Year 3 Flashcards

Question

# Anaesthetics, local Anaesthetics, local : Lidocaine, bupivacaine, levobupivacaine

Answer 1

**M** reversibly inhibit voltage-gated sodium channels, prevents initiation and propagation of action potentials **I** Surface anaethesia such as urinary catheterisation and venepuncture, local anaesthesia for suturing and lumbar puncture, regional anaesthesia/analgesia such as epidural, lidocaine second line for ventricular tachycardia **C** Liver disease, cardiac failure (due to liver blood flow), duration of action can be overtly increased with vasoconstrictor (adrenaline) **R** Urinary catheter- Instilagel. Subcuntaneous 1%- 3mg/kg, topical creams, plasters. **NEVER IV** **A** stinging during administration, other affects are uncommon when care to avoid OD or IV administration. If OD- drowsiness, restlessness, tremor fits, hypotension, arrhythmia ## Footnote *Administer the local anaesthetic early, then complete any other preparatory work for your procedure. Wait 5 minutes before testing the effect.*

Answer 2

**M** bind to muscarinic receptors as competitive inhibitor of acetylcholine. promoting bladder relaxation increasing bladder capacity. May reduce urinary frequency, urgency, urge incontinence. Work in overactive bladder at antagnosim at M3 receptor. **I** urinary frequency urgency and urge incontinence in overactive bladder, if bladder training doesnt work **C** Adverse with other antimuscarinics like tricyclic antidepressants, UTI, dementia (cognitive effect), caution in those at risk of intraocular pressure, caution with arrhythmia risk and urinary retention **R** Immediate-release antimuscarinics should be taken at roughly equal intervals, with or without food. MR forms should be taken at a similar time each day and swallowed whole, not chewed. Oxybutinin available as a patch. **A** dry mouth, tachycardia, constipation, blurred vision, urinary retention may occur if there is bladder outflow obstruction. Oxybutiynin congnitive effects as ccrosses BBB acting at M1. ## Footnote *chewing gum good for dry mouth symptoms*

Answer 3

**M** DOACs act on the **final** common **pathway** of the coagulation cascade: Factor X, Thrombin and Fibrin. Dabigatran directly inhibits thrombin and the "xa" inhibit Factor Xa. And thus prevent fibrin formation. **I** VTE for Tx and recurrence, Atrial Fibrilation to prevent stroke and systemic embolism in non-valvular AF associated with a risk factor **C** Avoid in active clinically significant bleeding and those with risk of bleeding such as ulceration, cancer, recent surgery. Eliminates via CYP450 so reduce dose/ alternatives in those with hepatic and renal disease. Avoid in pregnancy and breastfeeding. The anticoagulant effect is increased by macrolides, protease inhibitors, and fluconazole and decreased by rifampicin and phenytoin. **R** PO. Rivaroxaban with food. Dabigatran cannot be crushed but 'xa' can. **A** Bleeding including greater risk of GI bleeds (less intercranial risk than warfarin), anaemia, GI upset, dizziness, elevate liver enzymes. ## Footnote *In emergencies, dabigatran can be reversed with idarucizumab (a humanised monoclonal antibody fragment that binds to dabigatran and its metabolites). Apixaban and rivaroxaban can be reversed with andexanet alfa (a recombinant, modified form of human factor Xa that acts as a ‘decoy receptor’ for factor Xa inhibitors).*

Answer 4

**M** Reduce size of prostate gland by inhibiting conversion of testosterone to dihydrotesterone but can take months for clinical difference to be seen. Hence second line **I** Benign prostatic hyperplasia Second line treatment after alpha blockers **C** Pregnancy **R** PO **A** Impotence, Reduced libido, Gynaecomastia, Can be used to help male pattern baldness as adrogen inhibition can help hair growth

Answer 5

**M** Metabolised in bacterial cells by nitrofuran reductase Damages the bacterial DNA and cause cell death Active against - E coli (g -ve) and staphcoc (g +ve) **I** Uncomplicated UTI first line treatment Because: Effective against most com uti patho Reaches therapeutic conc in urine through rental excretion Most bactericidal in acidic conditions - aka urine **C** Pregnancy, Babies < 3 mo, Renal impairement as impaired excretion increase tox and reduce effectivity Caution with long term use **A** GI upset Hypersensitivity Chronic pul reactions Hepatisis and peripheral neuropathy in long term Babies - haemolytic anaemia

Answer 6

**M** Phosphodiesterase inhibitor selective for type 5 This is mainly found in the SM of the corpus cavernosum of penis and arteries of lungs **I** Erectile dysfunction, Primary pulmonary hypertension **C**If vasodilation is risky aka, Recent stroke, ACS, significant CVD, Severe renal or hepatic impairment, dont give or lower the dose **A**Related to the fact its a vasodilator Flushing, Headaches, Dizzyness, nasal congestion More serious, Hypotension, tachy, palpilations If erection fails to subside - medical attention needed to prevent damage

Answer 7

**M** D2 receptors in the main receptor in the ctz. Dop also relaxes stomach and lower esophagus and inhibs gastoduodenal effects **I** Prophyaxis and treatment of nausea in many things but particulary reduced gut motilty **C** Gastrointenintal obstructions Perforation Extrapyraminal side effects more common in under 25 so avoid Dont combine with anti psycotics or dopmergic agents (park treatment) **A** Diarrhoea Extra pyrmindal sydrome Acute dystonic reaction

Answer 8

**M**H1 found in vomiting centre and in its comms with vestibular system **I** Proph and treatment of nausea and vomiting particaully in motion sickness and vertigo **C** Hepatic encephalopathy Avoid patient suseptiable to anticholeric side effect aka men with prostatic hypertrophy Sedation more if also on other sedative drugs Anticholergic effects more pronounced in patients taking antimusc, bronch dilators **A** Drowsiness Dry throat and mouth Tachy Palpitations

Answer 9

**M** High density of 5ht in ctz and seratonin is key NT released by gut in response to emetogenic stimulation **I** Nausea and vom, in context of GA and chemo **C** May prolong qt so just be caution Avoid taking with other drugs that prolong qt - antipsycotic, ssri **A** Rare but constipation, diarrhoea, and headache

Answer 10

**M** Targets γ-aminobutyric acid type A (GABAA) receptor in the brain. (Main inhibitory neurotransmitter) changes structure to facilitate binding odf GABA. **Depressant** effect on the synaptic transmission reduced anxiety, sleepiness, sedation, and anticonvulsive effects. **I** First line epilepsy and alcohol withdrawal. Sedation in palliatie care and inteventional procedures. Short term anxiety incl procedures. **C** additive to those of other sedating drugs, including alcohol and opioids. CYP inhibitors (e.g. amiodarone, diltiazem, macrolides, fluconazole, protease inhibitors) may increase their effects. **R** Oromucosal, IV, **A** dose-dependent drowsiness, sedation, and coma. There is relatively little cardiorespiratory depression in benzodiazepine overdose (in contrast to opioid overdose), but loss of airway reflexes can lead to airway obstruction and death. If used repeatedly for more than a few weeks, a state of dependence ## Footnote *Dont give Flumazenil- antagonist but can cause seizures that you cant fix becuase you block benzo receptor. *

Answer 11

**M**Infliximab & Adalimumab: Target TNF-α to reduce inflammation in autoimmune diseases. Denosumab: Inhibits RANKL, reducing bone resorption by inhibiting osteoclast activity. Rituximab: Binds to CD20 on B cells, leading to B-cell depletion. Omalizumab: Binds IgE, reducing allergic responses. **I**Infliximab & Adalimumab: Used in autoimmune diseases (e.g., rheumatoid arthritis, Crohn’s disease, psoriasis). Denosumab: Treats osteoporosis, bone metastases, and hypercalcemia of malignancy. Rituximab: Indicated for non-Hodgkin lymphoma, chronic lymphocytic leukemia, and some autoimmune conditions. Omalizumab: Treats allergic asthma and chronic urticaria not controlled by antihistamines. **C**All: Avoid in active infections due to immunosuppressive effects. Denosumab: Contraindicated in hypocalcemia. Omalizumab: Contraindicated in patients with a history of severe hypersensitivity to the drug. **R** Infliximab & Rituximab: IV infusion. Adalimumab, Denosumab, & Omalizumab: Subcutaneous (SC) injection. **A** Common: Infections (increased risk for all due to immunosuppression). Infliximab & Adalimumab: Infusion or injection reactions, headache, nausea. Denosumab: Hypocalcemia, osteonecrosis of the jaw, musculoskeletal pain. Rituximab: Infusion reactions, cytopenias, risk of progressive multifocal leukoencephalopathy (PML). Omalizumab: Injection site reactions, headache, rare risk of anaphylaxis.

Answer 12

**M** interact with receptors in the cytoplasm- pro inflammatory IL, cytokines, chemokines are downregulated whilst antiinflammatory proteins are upregulated. **I**: Asthma airway inflammation and shortterm control where B2 agonist is insufficient **C** In COPD risk of pneumonia. Risk of paradoxical bronchospasm w wheezing. Systemic corticosteroid has adrenal suppression, osteoporosis and in children growth stunting. If prescribed Cyp P450 inhibitors, inhibits inhaled corticosteroid metabolism (systemic symptoms) **R** Metered-dose Inhaler (MDI) or dry powder inhaler (DPI). Beclamethasone 'extrafine; is 3.5 times more potent than a standard inhaler, Fluticasone proprionate is 2 times more potent that budesonide **A** changes in taste sensation and voice, oral candidiasis.

Answer 13

**M**have antiinflammatory and vasoconstriction effects. in rhinitis this reduces mucosal inflammation, oedema and secretions. **I** Prevention and tx of seasonal or perennial allergic rhinitis where antihistamines are insufficient, first line tx to shrink nasal polyps **C** local adverse effects such as nasal irritation, epistaxis, pharyngisitis and change in sense of smell and taste. Occular adverse effects are rare. Systemic adverse effects are less common with mometasone and fluticasone as lesser bioavailability **R** Nasal Spray with fixed drug per spray. starting dose 100mcg, once daily for mometasone and fluticasone or 12-hrly for beclometasone **A**. DO NOT use in coexisting nasal infection, nasal trauma or surgery, avoid in Pulmonary TB

Answer 14

**M** in skin suppresses inflammation during flares and reduces recurrence but not curative. **I** Inflammatory skin conditions incl eczema and psoriasis to tx disease flares or control chronic disease where emollients alone are ineffective **C**do not use in untreated bacterial, fungal or viral infection as this can worsen spread. Avoid for *potent* for use on face, genitals and axillae where the skin is thin or flexural **R** potent (e.g. hydrocortisone 0.1%–2.5%), moderately potent (e.g. betamethasone valerate 0.025%) potent (e.g. betamethasone valerate 0.1%) or very potent (e.g. clobetasol propionate 0.05%). **A** usually limited to site of application- skin thinning, striae, telangiectasia, contact dermatitis, worsening/spreading untreated infection. On face they can cause perioral dermatitis or acne. Withdrawal can occur with skin flare. Emollients increase efficacy of topical corticosteroids so may allow a lower-potency drug to be used reducing adverse effects. Seperate application by *15* minuets to allow for absorption ## Footnote Think as finger tip unit- 5mm tube should cover palms and fingers of both hands.

Answer 15

**M** bind to cytosolic glucocorticoid receptors to regulate gene expression. modifies immune response. Upreg antiinfl. genes and downreg pro-infl. genes **I** allergic or inflammatory disorders, anaphylaxis, exacerbations of asthma or COPD; suppression of AutoIx disease; reduce tissure damage in response to infection- bacterial meningitis, COVID19; some cancers or to reduce tumour associated swelling; hormone replacement in adrenal insufficiency or hypopituitarism. **C** prescribe with caution in people with infection and children (suppress growth). Caution with NSAIDS as can increase risk of peptic ulceration and GI bleeding. Can increase hypokalaemia when used with B2 agonists, loop or thiazide diuretics. Efficacy can be reduced with cP450 inducers. **R** Once-daily corticosteroid treatment should be taken in the morning, to mimic the natural circadian rhythm and reduce insomnia. antiinflammatory activity of hydrocortisone 100 mg is approximately equivalent to prednisolone 25 mg and dexamethasone 4 mg. If PO inappropriate (ibd, anaphylaxis) IV hydrocortisone may be used. **A** immunosuppresion risk of infection. metabolic effects of diabetes mellitus and osteoporosis. Increased catbaolism causes proximal muscle weakness and skin thinning. Mood and behavioural changes include insomnia, confusion, psychosis. Hypertension, hypokalaemia, oedema can result from mineralocorticoid actions. Can suppress ACTH in prolonged tx this can cause adrenal atrophy. If then, corticosteroid is removed, adrenal crisis with CVS collapse may occur. ## Footnote Can reduce immune response to vaccine.

Answer 16

**M** B2 found in s.m of bronchi gut uterus and blood vessels. Stimulation leads to smooth muscle relaxation and bronchodilation. ALSO stimulates Na/K-ATPase pumps on cell membranes can be adverse or benefit as hyperkalaemia treatment **I** Asthma (SABA) to relieve bronchospasm LABA added to Inhaled cortiocosteroids. COPD SABA relieves breathlessness and exercise limitation. If SABA inefficient, combine LABA or inhaled cortiocosteroid. **C** LABA should only be used in asthma if inhaled corticosteroid part of therapy as LABA without is associated with increased asthma deaths. Caution in CVS disease as tachycardia may provoke angina or arrhythmia especially at high dose. **R** inhaled as aerosol metered-dose or dry powder inhalers. In hospital tx regular nebulised therapy is used acutely. Inhalation via spacer also appropriate. **A** tachycardia, palpitation, anxiety, tremor, headache. Hypokalaemia and elevated serum lactate at high doses. Promotes glycofenolysis so may cause hyperflycaemia. LABA can cause muscle cramps. ## Footnote Spacers also reduce oropharyngeal deposition and therefore oral adverse effects.

Answer 17

**M** Incretins such as GLP1 and GIP are released by the intestine throughout the day. Incretins are rapidly inactivated by hyrolysis by the enzymes DPP4. DPP4 inhibitors lower blood glucose by preventing incretin degradation and increasing plasma concentrations of their active forms. Actions are glucose dependents. Less likely to cause hypoglycaemia than sulphonylurea. **I**T2 diabetes,options for combination therapy with metformin if blood glucose not adequateky controlled or monotherapy if metformin is contraindicated/not tolerated. **C** contra in people with hypersensitivity to the drug class. DO NOT use in tx of T1 diabetes or ketoacidosis. DO NOT use in pregnancy or breastfeeding. Caution in age > 80 and those with Hx of pancreatitis. Dose reduction advised in moderate to severe renal impairment. Saxagliptin avoid in hepatic impairment. Hypoglycaemia risk increased with coprescription of other antihyperglycaemics. **R** PO t.d.s or fixed dose with metformin combination to time with metformin doses. **A** GI upset, headache, nasopharyngitis, peripheral oedema. Hypoglycaemia can occur. Small risk of acute pancreatitis so stop drug if persistent abdo pain. ## Footnote The efficacy of DPP-4 inhibitors is reduced by drugs that elevate blood glucose, e.g. prednisolone, thiazide, and loop diuretics. no evidence that they reduce the risk of vascular complications.

Answer 18

**M**: inhibits neuronal sodium channels, stabilising resting membrane potentials **I** seizure prophylaxis in epilepsy, trigeminal neuralgia **C** absence and myoclonic seizures, tetarogenic (neural tube defect), Steven Johnson syndrome risk in Han CHinese and Thai origin, Hepatic, renal, cardiac disease, CYP inhibitors, other antiepileptic, antipsychotics, tramadol **R** PO, PR, low dose increased gradually **A** GI upset, neurological effect incl dizziness and ataxiam oedema, hyponatraemia, hypersensitivity

Answer 19

**M** negatively chronotropic (reduces HR) and positively inotropic (increases contractile folce), increases vagal tone in AF In HF, inhibits Na+/K+ ATPase pumps to increase contractile force of myocytes **I** AF to reduce ventricular rate, in severe HF, may be added if Tx not efficient **C** Loop and thiazide, Amiodarone, CCB, spironolactone and quinine can increase toxicity Second degree Heart block, intermittant block, ventricular arrhytmia, lower dose in renal failure **R** PO, IV **A** bradycardia, GI upset, rash, dizziness, visual disturbance Is ## Footnote Foxglove- has a tight therapuetic margin

Answer 20

**M** inhibit prostaglandin synthesis from arachidonic acid by inhibiting cyclo-oxygenase (COX). COX-2 is expressed in response to inflammatory stimuli. It stimulates production of prostaglandins that cause inflammation and pain **I** As needed for mild moderate pain and fever Regular treatment for pain due to inflammation incl RA, severe OA, acute gout **C** contraindicated in ✖ severe renal impairment, ✖ heart failure, ✖ liver failure and known ✖ NSAID hypersensitivity. They should be avoided in ▲ peptic ulcer disease ▲ cardiovascular disease and milder forms of ▲ renal impairment. **R** PO, Gel, Suppositories, Injectible **A** Diclofenac suppository only hospital as BP drop GI toxicity, renal impairment, and major adverse cardiovascular events renal impairment. Other adverse effects include hypersensitivity reactions, e.g. bronchospasm and angioedema, and fluid retention ## Footnote therapeutic benefits of NSAIDs are principally mediated by COX-2 inhibition, and adverse effects by COX-1 inhibition

Answer 21

**M** inhibits the cholinesterase enzymes that break down acetylcholine in the CNA and increases availability for neurotransmission **I** mild to mod alzheimers, mild to mod parkinsons (rivastigimine) **C** use with caution in asthma and COPD and those risk of peptic ulcers, AVOID in heart block or sick sinus, NSAIDs and ▲ systemic corticosteroids may increase the risk of peptic ulceration. Use alongside ▲ antipsychotics may increase the risk of neuroleptic malignant syndrome. **R** Tablets, capsules, liquids, Rivastifmine as a patch. Donepezil should be taken at night (vivid dreams may occur) **A** GI upset (increased cholinergic activity), those with asthma or COPD may experience bronchospasm, peptic ulcers, bleeding, bradycardia, heart block, hallucinations and altered aggressive behaviour. Small risk of extrapyramidal symptoms and neuroleptic malignant syndrome

Answer 22

**M** an acetylcholinesterase inhibitor. cant cross BBB **I** Myasthenia gravis, underactive bladder, with atropine to reverse neuromuscular blocking medication, off-labels POTS **C**contraindicated in cases of mechanical intestinal or urinary obstruction and should be used with caution in patients with bronchial asthma **R** PO, IV **A** Sweating, Diarrhea, Nausea, Vomiting, Abdominal cramps, Increased salivation, Tearing Increased bronchial secretions, Constricted pupils, Facial flushing due to vasodilation, Erectile dysfunction

Answer 23

**M** Replenishes the glutathoine which clears NAPQI, with mucus it breaks disulfide bonds and reduces mucus viscocity **I** IV acetylcysteine is the antidote for paracetamol Oral carbocisteine and acetylcysteine as mucolytics **C** Peptic ulcer disease, consider paracetamol poisioning use even if previous anaphylactoid reaction (check with superior) **R** Acetylcysteine is diluted in glucose 5% for IV infusion. Oral carbocisteine is available as capsules or oral solution **A** anaphylactoid in IV after paracetamol poisoning, NOT Anaphylaxis, GI upset, GI bleeding, bronchospasm (use bronchodilator first) ## Footnote Expensive BUT acetylcysteine is also available as eye drops (artificial tears). It reduces the viscosity and tenacity of mucus in the eye and is of potential benefit in the treatment of dry eye syndromes.

Answer 24

**M** mineralocorticoid receptors in the distal tubules of the kidney to ***increase the activity of luminal epithelial sodium (Na+) channels (ENaC)*** inhibit the effect of aldosterone by competitive inhibition at mineralocorticoid receptors. This ***increases sodium and water excretion and potassium retention*** **I** Ascites and oedema, chronic HF, primary hyperaldosteronism *eplerenone is licensed for the treatment of heart failure only* **C** ✖ severe renal impairment, ✖ hyperkalaemia, and ✖ adrenal insufficiency, avoid in pregnant and lactating. combination of an aldosterone antagonist with other ▲ potassium-elevating drugs, including ▲ ACE inhibitors and ▲ angiotensin receptor blockers (ARBs), increases the risk of hyperkalaemia. **R** Taken with food, PO **A** hyperkalaemia, gynaecomastia, liver impariment and jaundice. Spironolactone is a cuase of SJS

Answer 25

**M** inhibits xanthine oxidase. Xanthine oxidase metabolises xanthine (produced from purines) to uric acid **I** prevent recurrent attacks of gout, prevent uric acid and calcium oxalate renal stones, prevent hyperuricaemia dn tumour lysis syndrome in chemo **C** should not be started during an ✖ acute attack of gout, Recurrent skin rash or signs of more ✖ severe hypersensitivity to allopurinol are contraindications to therapy, ▲ renal impairment or ▲ hepatic impairment. **R** PO, after meals with good hydration **A** can trigger a gout attack, but can be reduced with NSAID or cholchine during initiation Skin rash- SJS or TENS risk Allopurinol hypersensitivity syndrome is rare ## Footnote Co-prescription of allopurinol with ▲ angiotensin-converting enzyme (ACE) inhibitors or thiazides increases the risk of hypersensitivity reactions,

Answer 26

**M** soothing effect, help protect eye from abrasive damage. Usually an electrolyte with a viscocity agent like cellulose polymer. **I** First-line dry eyes, including keratoconjunctovitis sicca, Sjögrens **C** Preservative-free products are preferable for long-term or frequent application (more than four times daily), to avoid adverse reactions to the preservative. **R** liquid- *hypromellose*; Gels - *carbomers*, Oitnments- *liquid paraffin* (last longer but with blurred vision) **A** Stinging, Blurring, if not preservative free may cause local inflammatory reaction ## Footnote Eye care is therefore an essential component of good-quality intensive care. Prescription of an ocular lubricant, e.g. hypromellose 0.3%, 1 drop per eye 4-hrly, should be considered for all patients with impaired consciousness (including due to sedation).

Answer 27

**M** to suppress LH/FSH release and hence ovulation. In symtpom relief, they can eleviate vaginal dryness, vasomotor instability. Offers reduced menstrual pain and improvements in acne **I** Hormonal contraception AND Hormone replacement therapy, **C** ✖ breast cancer, should be avoided with personal or family Hx of VTE, thrombogenic mutation or risks for CVD Cytochrome P450 inducers (e.g. rifampicin, carbamazepine) may reduce contraceptive efficacy **R** PO/ If a COC pill is started within the first 6 days of the woman’s cycle, no additional contraception is needed. Beyond this, a barrier method should be used or sex avoided for the first 7 days **A** may cause irrefular bleeding, mood change, NO WEIGHT GAIN, doubles risk of VTE but risk is low, ## Footnote POP do not increase risk of VTE or CVD Continuous or extended use of the COC pill (i.e. without pill-free intervals) is unlicensed for most brands, but is safe and effective

Answer 28

**M** Clinical effects are usually not apparent until the serum potassium falls below 3 mmol/L (normal range 3.5–5.0 mmol/L) Potassium supplementation results simply in increased potassium excretion and only minimal effect on serum concentration therefore MUST start potassium sparing diuretic or similar **I** Prevention and Tx of potassium depletion and hypokalaemia. Addition of potassium sparing diuretic is preferred. IV KCl is preferred in initial severe hypokalaemia **C** contraindicated in ✖ hyperkalaemia and take care when risk of ▲ renal impairment. Contra with drugs that increaese potassium incl ACEi NSAID etc. **R** Effervescent tablets (e.g. Sando-K®) are stirred in about half a glassful of water for administration. **A** Unpalatable, may inadvertently increase intake.

Answer 29

**M** **Prostaglandin** F2α analogues act via prostaglandin receptors to increase expression of matrix metalloproteinases, reducing resistance to aqueous humour outflow **carbonic** anhydrase inhibitors reduce aqueous humour production. **I** first line to lower intraocular pressure in open-angle glaucome and ocular hypertension. Preferred over β blockers as less side effects. **C** Caution is lens is absent and with those at risk of iritis uveitis or macular oedema **R** eye drops (best in evening, remove contact lenses) **A** Local eye discomfort and blurred vision. Prostaglandin cause conjunctival reddening and change in eye colour (1/3 people) ## Footnote Advice that may be given for all eye drops is that it is helpful to gently compress the medial canthus (the nasal ‘corner’) of the eye for about 1 minute, immediately after instilling the drop. This reduces drainage through the lacrimal duct, lowering systemic absorption of the drug.

Answer 30

**M** * **PGE2** synthesised in uterine mucosa and stimulated contraction and thins the cervix, * **PGE1** in sm muscle stimulates cAMP and vasodilation/relaxation except in the penis with erection * **PGI2** has vasodilatory effects **I** Induction of labour (dinoprostone), Erectile Dysfunction (alprostadil), Termination of pregnancy (Misoprostol), Vasodilator in Pulmonary HTN, and PVD (iloprost) **C** Induction of labour with dinoprostone should not be attempted if there are ✖ risk factors for difficult delivery prostaglandins should be used with caution in people with ▲ severe cardiac disease. Iloprost contra in bleeding risk and DOACs and warfarin **R** * Dinoprostone is administered as a gel, pessary or vaginal tablet. * Alprostadil is prescribed for urethral application. Misoprostol and iloprost are used in specialist practice **A** * Dinoprostone may cause uterine hyperstimulation increase the risk of uterine rupture. * Alprostadil may cause prolonged painful erections (priapism) that can lead to tissue ischaemia. * Iloprost may cause problematic hypotension when given systemically. * Prostaglandins may cause nausea and vomiting from stimulation of gastro-intestinal smooth muscle. ## Footnote misoprostol is an alternative for people who cannot tolerate PPIs.

Answer 31

**M** They act by irreversibly inhibiting H+/K+-ATPase in gastric parietal cells and supresses gastric acid production nearly completely **I** Prevention of peptic ulcer disease, incl NSAID, Tx of GORD and dyspepsia incl Barretts, eradicated H Pylori (w/ Abx) **C** may mask symptoms of gastric and oes cancer and ulcer disease w H Pylori. PPI can increase risk of fracture so caution in risk of osteoporosis Warning with Clopidogrel as may reduce effect of antiplatelet **R** Oral PPI with food, a.m. IV slow injection or infusion **A** GI upset, headache, may increase C diff colitis risk. Hypomagnesaemia if long term -> caution for neuromuscular symptoms and arrhythmias. ## Footnote PPIs should preferably be withheld for 2 weeks before testing. This is because they increase the chance of a false-negative result

Answer 32

**M** Agonist of adenosine receptors. Increases refractoriness (resistance) in the AV node temporarily allowing circiut to resume at the SA node (Cardioversion) 10 second half life **I** Diagnostic and therapeutic for Supraventricular tachycardia **SVT** (if shock present, prefer electrical cardioversion) **C** contraindicated in ✖ hypotension, ✖ coronary ischaemia or ✖ decompensated heart failure. May induce bronchospasm in susceptible individuals, so should be avoided in ✖ asthma and ▲ COPD. Use lower dose in heart transplant pat. ▲ Dipyridamole, an antiplatelet agent, blocks cellular uptake of adenosine **R** large-bore cannula (e.g. 18 G [green] or bigger), sited as proximally as possible (e.g. in the antecubital fossa). Rapid injection, followed with Sodium chloride flush. Seen on ECG 10-15 seconds. **A** can induce bradycardia and even asystole and feeling of impending doom and breathlessness

Answer 33

**M** catalyse conversion of plasminogen to plasminogen and dissolve fibrinous clots. **I** acute iscahemic stroke within 4.5 hours, in ST elevation acute coronary syndrome within 12 hours, for massive PE **C** factors that predispose to ✖ bleeding, bleeding disorders, severe hypertension. In acute stroke, ✖ intracranial haemorrhage. ✖ Previous streptokinase treatment is a contraindication to repeat dosing (Abs) Risk of haemorrhage is increased in people taking anticoagulants and antiplatelet **R** high-dependency area, powder reconstituted with sterile water as injuction of IV infusion with 0.9% NaCl **A** nausea, vomitting, bruising, hypotension STOP if bleeding, allergic reaction, cardiogenic shock and cardiac arrest.

Answer 34

**M** binds to opioid (especially μ) receptors as competitive antagonist. Little effect if opioid not present. **I** Acute treatment of opioid toxicity associated with respiratory or neurological depression. **C** caution should be exercised in people with ▲ opioid dependence as could cause opioid withdrawal. Lower doses should be used in ▲ palliative care to reduce the risk of complete reversal of analgesia. **R** pre filled syringe or IV, IM, SC, intranasally **A** Withdrawal may be significant: presents with pain (if the opioid was being taken for its analgesic effect), restlessness, nausea and vomiting, dilated pupils, and cold, dry skin with piloerection (‘cold turkey’).

Answer 35

**M** Supplemental oxygen therapy increases PO2 in alveolar gas (PAO2), driving more rapid diffusion of oxygen into blood. **I** acute hypoxaemia, and chronic hypoxaemia, accelerate reabsorption of pleural gas in pneumothorax, reduce carboxyhaemoglobin in CO poisoning **C** chronic type 2 respiratory failure (shut off carbonic drive) **A** discomfort of the mark,

Answer 36

* Reservoir Marks (continuous, 15L/min) * Venturi (blends air) * Nasal cannulae (24-50% O2 at 2-6 L/min) * Humidified high-flow (warmed can provide high FiO2) ## Footnote Oxygen therapy should always be guided by a written prescription, except in emergencies when it may be administered first and prescribed later.

Answer 37

**M** Antacids buffer stomach acids, alginates increase viscocity of stomach contents preventing reflux **I** GORD heartburn symptom relief; dyspepsia short term indigestion **C** Caution if containing Na and K in hyperkalaemia, fluid overload, renal failure Can interact with ACEi, some Abx, bisphosphonates, digoxin, levothyroxin, PPI and can increase excretion of aspirin and lithium **R** PO or chewable tablets, Taken following meals, for infants oral powder can be mixed with feeds or waters BUT NOT thickened infant milk **A** Magnesium salts can cause diarrhoea, whereas aluminium salts can cause constipation.

Answer 38

**M** Similar to benzodiazepines, GABA (a) receptor with allosteric modulation to increase GABA binding. Depressent effect including sleepiness. **I** Short term treatment of insomnia which is debilitating or distressing **C** caution in older people as more sensitve to neuro effect, AVOID ✖ obstructive sleep apnoea, ✖ respiratory muscle weakness or ✖ respiratory depression Enhances antihistamines and benzodiazepine so avoid or warning. **R** PO tablets or capsules **A** Daytime sleepiness, rebound insomnia, neuro incl headache, confusion, nightmares and rarely amnesia. Zopiclone can cause taste disturbance where zolpidem causes Gi upset. Prolonged use leads (4weeks) to dependence and withdrawal incl headache, muscle pain, anirty ## Footnote not useful anticonvulsants, as they cannot be given by injection.

Answer 39

**M** Clotting factors 2,7,10 (vit K reliant) are prevented from forming through vitamin k epoxide reductase inhibition. **I** treat and prevent VTE recurrence (DOACS preferred), prevent arterial abolism from AF, prevent arterial embolisn from mechanical heart valves. **C** ontraindicated if there is ✖ active bleeding, avoided in the first trimester of ✖ pregnancy due to teratogenicity Interacts with CYP inducers and CYP inhibitros so caution on administration. **R** PO at 18:00 daily **A** Bleeding ## Footnote effect of warfarin can be reversed with phytomenadione (vitamin K1)

Answer 40

**M** Facilitates cell proliferation, possibly aiding neural tube closure by supporting normal cell division during early pregnancy. **I**: Prevention of neural tube defects in pregnancy. Treatment of megaloblastic anaemia due to folate deficiency. **C**: Avoid sole replacement in combined vitamin B12 and folate deficiency to prevent worsening of neurological damage. **R** Oral (400 micrograms daily preconception/first trimester; 5 mg daily for high-risk pregnancies or folate deficiency anaemia). **A** Rarely toxic.

Answer 41

**M**Cobalamin is a cofactor in DNA synthesis and myelin production, critical for red blood cell formation and neurological function. **I**Megaloblastic anaemia due to vitamin B12 deficiency. Subacute combined degeneration of the cord. **C**Ensure folate is replaced concurrently in combined deficiencies to avoid neurological progression. **R**IM (e.g., hydroxocobalamin for initial treatment). Oral (e.g., cyanocobalamin in cases of mild deficiency without malabsorption). **A**Rarely toxic.

Answer 42

**M**Restores vitamin K-dependent clotting factor synthesis, reversing warfarin's effects and preventing vitamin K deficiency bleeding. **I**Prophylaxis of vitamin K deficiency bleeding in neonates. Reversal of over-warfarinisation. **C**Less effective in severe liver disease due to impaired clotting factor synthesis. **R**IM (e.g., 1 mg in neonates). IV (e.g., 10 mg for major bleeding). Oral (e.g., low doses for mild over-warfarinisation). **A**Rare risk of anaphylaxis with IV administration.

Answer 43

**M** Increases activity of GAD to increase GABA, inhibits VGNaC. Reduces neuronal excitability, supressing seizure discharge and propagation **I** seizure prophylaxis in epilepsy, selected cases of established convulsive status epilepticus that hasnt responded to benzodiazepine, bipolar disorder, prevent frequent migraine attacks **C** valproate should be avoided in ✖ girls and women who could become pregnant particularly around the time of ✖ conception and in the ✖ first trimester of pregnancy. Avoided in ▲ hepatic impairment and dose reduction is required in ▲ severe renal impairment. Inhibits hepatic enzymes so avoid lamotrigine and CYP drugs such as warfarin and carbapenems **R** enteric-coated tablets, capsules, granules, and oral solutions **A** GI upset, neurological and psychiatric effects incl tremor, ataxia, behavioural disruebances, thrombocytopenia and incredible liver enzymes. ## Footnote The efficacy of antiepileptic drugs is reduced by ▲ drugs that lower the seizure threshold (e.g. antipsychotics, tramadol).

Answer 44

**M** Should be broad activity (E Coli) but is limited by resistance. Combinational with sulfamethoxaole (co-trimoxazole) extends activity to fungus pneumocystis jirovecii Inhibits bacterial folate synthesis, with sulfamethoxazole inhibiting another part of the same pathway. **I** first line for acute lower UTI, prevention of recurrent UTI. Option for acne vulgaris and prostatitis. co-trimoxazole for precention of pneymocytis pneumonia in immune compromised. **C** DO NOT USE in **first trimester** as is a folate antagonist, use with caution in folate deficiency and renal impaitment. Neonates, older people and HIV more suscpetible to adverse effects ▲ potassium-elevating drugs (e.g. aldosterone antagonists, ACE inhibitors, ARBs) predisposes to hyperkalaemia. **R** PO tablets and suspension, IV must be diluted in NaCl 0.9 or Gluc 5 over 60-90 min. **A** GI upset and skin rash. Can impair haematopoiesis with megaloblastic anaemia, leukopenia and thrombocytopaenia. Can cause hyperkalamia.

Answer 45

**M** antifibrolynitic that binds to plasma inhibiting activation of plasmin. Promote haemotasis. **I** Second line treatment for menorrhagia, for epistasis, in major trauma to reduce mortality and postpartum haemorrhage in addition to other drugs **C**Avoid in people with a history of seizures and VTE disease. Avoided in DIC. Investigate for abnormal menstrual bleeding first. Can increase the risk of thromboembolism when combined with other drugs that have an increased risk risk such as COC **R** Tablet or injection. In trauma IV **A**GI upset, rash with IV use. Rare effects include DVT PE seizures and visual disturbances.

Answer 46

**M** Levothyroxine is synthetic T4, liothyronine is synthetic T3. Levothyroxine is preferred For long-term years, as liothyronine has a small short life and quick onset (trauma use) **I**Primary hypothyroidism, hypothyroidism secondary to hypopituitarism **C** Excessive doses give symptoms of hyperthyroidism. In people with coronary artery disease cautiously monitor as risk of cardiac ischaemia. In hypopituitarism Treat with corticosteroids first to avoid Addisonian crisis **R** PO, tablet **A** GI upset palpitations, arrhythmia angina tremor, restlessness, insomnia. weight loss is expected.

Answer 47

**M** Ford spectrum with activity against both g + and g -. Resistance is common but less problematic for Tigecycline. Inhibit bacterial protein synthesis binds to ribosomal 30 S so is **bacteriostatic** **I** Acne Bulgars, lower respiratory tract infections including infective exacerbation of COPD and pneumonia chlamydia infection including PID infection such as typhoid malaria and Lyme disease. Severe skin soft tissue and abdominal infections when other options are limited. **C** Avoid in pregnancy breastfeeding and children under 12 years of age as binds to bone and teeth. caution in renal impairment **R** PO, but Tigecycline available as IV infusion **A**GI upset But with a lower risk of CDiff infection than other broad spectrum. Oesophageal ulceration and dysphasia, photosynthesis activity, discolouration and all hyperplasia of tooth enamel in children. Rare effects include hepatotoxicity and interocranial hypertension.

Answer 48

**M** Find irreversibly to bacterial ribosomes 30 S subunit and inhibits protein synthesis. Streptococci and anaerobic bacteria do not have the transport system required and so are aminoglycoside resistant. G -ve negative aerobic bacteria **I** Sepsis, pyelonephritis and complicated UTI, intra abdominal infection, endocarditis, topical neomycin an option for otitis externa **C** ddose adjust to prevent renal, cochlear, and vestibular damage, particularly in ▲ neonates, ▲ older people and those with ▲ renal impairment. can impair neuromuscular transmission **R** IVI and parenterally (no gut absorption) **A** Nephrotoxicity and ototoxicity, ## Footnote Aminoglycosides have a narrow therapeutic index, meaning that there is little ‘safety margin’ between the clinically effective dose and the toxic dose. One means of tailoring the dose to the individual is to base it on body weight

Answer 49

**M** In UC, releases 5- amino salicylic acid which is anti-inflammatory and immunosuppressive to act on the gut. **I** First line option for mild moderator UC, Sulfasalazine Is option for rheumatoid arthritis used with a DMARD **C** contraindicated with aspirin hypersensitivity **R** Enema or suppository As first line or oral formulation may be used **A** Mesalazine generally causes fewer side effects than sulfasalazine. GI upset, headache. RARE leukaemia thrombocytopenia and renal impairment. Reversible oligospermia. Hypersensitivity reactions. ## Footnote Drugs which adapt pH such as PPI and lactulose may affect medications with pH sensitive coating

Answer 50

**M** Many effects on myocardial cells including blockade of sodium, calcium and potassium channels and antagonism of alpha and beta adrenergic receptors. This reduces automaticity, slows conduction velocity and increases resistance to depolarisation (refractoriness) Including at the AV node. Can help convert and maintain sinus rhythm. **I** Atrial fibrillation, atrial flutter, supraventricular tachycardia, ventricular tachycardia, refractory ventricular fibrillation **C** avoided in ▲ severe hypotension, ▲ heart block, and ▲ active thyroid disease. Avoid/ rethink doses in digoxin, diltiazem, verapamil. Reduce grape juice bracket CP450 3A4 **R** IV bolus **A** Hypertension, pneumonitis, bradycardia, AV block, hepatitis, photosynthesis activity and grey discolouration to skin. Thyroid abnormalities (contains iodine). ## Footnote in cardiac arrest, in which it is given for VF or pulseless VT immediately after the third shock in the Advanced Life Support (ALS) algorithm. The dose is 300 mg IV, followed by 20 mL of 0.9% sodium chloride or 5% glucose as a flush.

Answer 51

**M** Inhibits reuptake of 5HT increasing its availability **I** First line for moderate to severe depression and in mild depression. Panic disorder, OCD. **C** Caution on epilepsy and peptic ulcer disease. Caution in young people as increased risk of self harm and suicidal thoughts. Caution in people with hepatic impairment Do not give with monoamine oxidise inhibitors and other serotonergic drugs. Bleeding risk is increased if taken with anticoagulant aspirin or NSAID, do not use with drugs that prolong the QT interval **R** Tablets and oral drops **A** GI upset, appetite changes, weight changes and hypersensitivity reactions. Hyponatraemia in older people, suicidal thoughts and behaviour, may lower seizure threshold, prolonged QT interval, increase risk of bleeding. Sudden withdrawal can cause GI upset neurological and flu like symptoms and sleep disturbance ## Footnote Fluoxetine interacts with tamoxifen

Answer 52

**M** Venlafaxine and duloxetine are a serotonin–noradrenaline reuptake inhibitors (SNRIs), Mirtazapine is a tetracyclic antidepressant Increases availability of mono means which improves mood. Tricyclic antidepressants can also be an antagonist of histamine and muscarinic receptors **I** Major depression if SSRI ineffective, generalised anxiety disorder ( venlafaxine duloxetine) And diabetic neuropathy (duloxetine) **C** Reduce dose in hepatic and renal impairment. Avoid duloxetine and severe renal impairment. Caution with venlafaxine in people at risk of arrhythmias. Can interact with SSRI **R** PO, Mirtazapine should be taken at night to mitigate (or benefit from) its sedative effects. **A** GI upset, dry mouth, neurological effects including headache. Less common: hyponatraemia, serotonin syndrome. Suicidal fault and behaviour may increase. Then affecting prolonged QT interval. Sudden drug withdrawal can cause GI upset neurological and flu like symptoms Mitrazepine may cause bone marrow suppression. ## Footnote Counterintuitively, some evidence suggests that mirtazapine’s sedative effects are less severe at higher doses. This may be because at low dose its (sedating) antihistamine effect predominates, while at higher doses this is counteracted by increased monoaminergic effect

Answer 53

**M** Tricyclic antidepressants inhibit re-uptake of 5HT and no adrenaline from the synaptic cleft. They also block macaronic histamine alpha-adrenergic and dopamine receptors (extensive adverse effects). **I** Second line treatment for moderate to severe depression where SSRIs are ineffective, neuropathic pain, IBS, amitriptyline to prevent frequent migraine and attacks **C** Caution required an older people and those with epilepsy of CVS disease. Antimuscarinic affects me worse and constipation, glaucoma and prostatic enlargement. Do not give with monoamine oxidase inhibitor **R** Tablet or oral solution **A** Blockage of anti-muscular and a receptors causes dry mouth, constipation, urinary retention, blurred vision and can exacerbate cognitive impairment. Blockage of histamine and uric receptors cause a sedation and hypertension This can also cause cardiac adverse effects, including prolongation of the QT and QRS duration. In the brain seizures hallucinations in mania Blockage of dopamine receptors can cause breast changes sexual dysfunction and rarely extrapyramidal symptoms (tremor, dyskinesia) Tricyclic antidepressants are dangerous and overdose and sudden withdrawal can cause GI upset neurological and flu like symptoms

Answer 54

**M** Ergosterol is only on fungal cell membranes and is a target. polyene antifungals (nystatin) binds to ergosterol creating a pore so ions leak out. Clotrimazole and Triazole antifungals inhibit ergosterol synthesis impairing the cell membrane. **I** Treatment of local fungal infections include an or referring, vagina or skin. Systemic treatment of invasive or disseminated fungal infections (specialist). **C**Fluconazole should be prescribed with caution and liver disease and cutie interval prolongation. A dose reduction is required in moderate renal impairment. Avoid in pregnancy. Fluconazole inhabits P4 50 caution with carbamazepine, warfarin, diazepam, simvastatin, sulphonylureas **R** Topical, PO, IV **A** Local irritation for creams, PO with GI upset, headache, increase in liver enzymes, hypersensitivity. Rare includes severe hepatic toxicity, prolonged QT interval, severe hypersensitivity.

Answer 55

**M** Find some muscarinic receptors acting as a competitive inhibitor of acetylcholine. Increases heart rate and conduction (M2), reduces smooth muscle tone in respiratory tract, gut and urinary tract (M3), and reduces secretions from glands in the respiratory tract and gut (M1, M3). In the eye causing relaxation of the pupillary constrictor and celery muscles (M3). Inhaled antimuscarinic relieve airway obstruction in COPD and asthma **I** In COPD LAMA, an acute severe asthma SAMA and LAMA if control is insufficient with ICS **C** Use with caution and people susceptible to angle closure glaucoma, at risk of arrhythmias, urinary retention. Interactions are unproblematic. **R** Inhaled medication **A** Dry mouth is common. Inhalation may irritate respiratory tract with cough or horse voice. Can cause tachycardia, constipation, retention, blurred vision. Inhaled therapy Delivers lower dose to systemic circulation

Answer 56

**M** Find muscular receptors acting as competitive inhibitors of acetyl: **I** Atropine and glycopyrronium our first line options in the management of severe bradycardia, first line for irritable bowel syndrome and in palliative care to prevent respiratory secretions **C** No contra indications for life-threatening bradycardia. Caution should be excised in angle closure glaucoma, avoid in arrhythmia risk. May causes urinary retention in BPH. **R** IV, PO, SC **A** Can cause tachycardia, dry mouth, constipation. Urinary retention by blocking the Truse muscle, blurred vision due to oculus effects. M1 in the brain has central effects including drowsiness and confusion. Hyoscine butylbromide, glycopyrronium Are less lipid soluble and so have less brain effects ## Footnote Take care not to confuse hyoscine butylbromide and hyoscine hydrobromide.

Answer 57

**M** ADP receptor antagonist prevent platelet aggregation by binding irreversibly to ADP receptors on the surface of platelets **I** Acute coronary syndrome treatment, prevent coronary artery stent occlusion, secondary prevention of major adverse cardiovascular events **C** Should not be prescribed for people with active bleeding may need to be stopped before elective surgery. Caution in renal and hepatic impairment. Clopidogrel is a pro drug and is affected by CYP inhibitors. Choice of PPI is important as may inhibit Clopidogrel Prescription with other anti-drugs anticoagulants and NSAID can increase bleeding risk **R** PO **A** Most common effect is bleeding. GI upset, dyspepsia, Abdo pain, diarrhoea is also common. Rare thrombocytopenia.

Answer 58

**M** Irreversibly inhibits COX to reduce production of thromboxane and reduces platelet aggregation. Lifetime 7-10 days. **I** Tx ACS and acute ischaemic stroke, secondary prevention of major CVS events, at high dose for mile to moderate pain and fever **C** Risk of Reyes under 16 y.o, avoid in aspirin hypersensitivity, avoid in 3rd trimester (premature closure of ductus arteriosus). Caution in peptic ulcer disease and gout. Acts synergistically w other antiplatelets- caution in dosing for at risk groups **R** PO, PR **A** GI upset, peptic ulceration and haemorrhage, hypersensitivity incl bronchospasm. In regular high dose can cause tinnitus. Overdose is life-threatening. ## Footnote In the UK, aspirin is not recommended or licensed for use in primary prevention of cardiovascular disease (i.e. in people who have not previously had an event). The reason is that large-scale, randomised controlled trials and meta-analyses have found that the absolute risk of major adverse cardiovascular events in this group is low (around 1/500), and the benefits of preventing a proportion of these with aspirin are offset by the increased risk of serious bleeding (around 1/1000).

Answer 59

**M** block post synaptic D2 receptors. Acts on the **Mesolimbic**(main mode)/mesocortical, **nigrostriatal** and **tuberohypophyseal** pathways (accounts for side effects too) Acts on D2 in the CTZ to reduce nauea and vomitting. All are sedative to an effect. **I** Rapid tranquilisation, schizophrenia (where 2nd gen problematic), bipolar disorder, nausea and vomiting (incl palliative care) **C** Older people are sensitive to antipsychotics, avoid in dementia (risk of death and stroke), avoid in parkinsons (extrapyramidal effect) Long list of contra drugs including prolong QT interval. **R** PO, IM, IV Haloperidol (acute effects, specialist use only) **A** Extraoyramidal effects (nigrostirtiatal) incl acute dystonic reactions, akathisia, neurolepticmalignant syndrome. Tardive duskinesia is a late adverse effect (months or years). Drowsiness, hypotension, QT prolongation, arrhythmia, erectile dysfunction. Hyperprolactinaemia (tuberohypophyseal blockade)(incl menstrual change and breast pain)

Answer 60

**M** Same as first line BUT second-generation antipsychotics have greater activity at other receptors (particularly 5-HT2A antagonism), and a **characteristic of ‘looser’ binding to D2 receptors** (in the case of clozapine and quetiapine). This may explain why they have a lower risk of extrapyramidal symptoms. **I** Schizophrenia, especially where extrapyramidal side effects prevent use of first gen. Bipolar disorder **C** caution in CVS disease, clozapine must not be used in severe heart disease or nuetropenia Hx **R** PO, IM **A** extrapyramidal effect (less common), metabolic disturbances, weight gain, DM, lipid changes. Can prolong QT and arrhythmia. Risperidone acts on tuberohypophyseal pathway with prolactin secretion - breast symptoms and sexual dysfunction. Clozapine can cause neutrophil deficiency (agranulocytosis) in 1%

Answer 61

**M** HSV 1 &2 have DsDNA which has a HSVDNA polymerase. Aciclovir inhibits the herpes-DNApolymerase. **I** Tx of herpesvirus infections, HSV and VCZ, supression of reccurent herpes simplex attacks **C** crosses placenta and breast milk so caution in pregnancy and breastfeeding. Caution in severe renal impariment Renal function should be monitored when prescribed with drugs that increase nephrotoxicity risk **R** PO, IV **A** headache, dizziness, GI upset, skin rash, IV can cause phlebitis. ## Footnote Aciclovir is relatively water insoluble. During high-dose IV therapy, delivery of a high concentration of aciclovir into the renal tubules can cause precipitation, leading to crystal-induced acute renal failure

Answer 62

**M** * oseltamivir and zanamivir inhibit neuraminidases, viral surface enzymes important for entry into and release from host cells. * molnupiravir and remdesivir are nucleotide analogues that block viral RNA synthesis, * nirmatrelvir (with ritonavir) is a protease inhibitor that inhibits viral replication. * nucleoside/nucleotide (e.g. emtricitabine, tenofovir) and non-nucleoside (e.g. efavirenz) reverse transcriptase inhibitors (NRTIs and NNRTIs, respectively) * Protease inhibitors (e.g. atazanavir) inhibit the enzyme which cleaves inert polyproteins into structural and functional viral proteins **I** acute tx of viral incl influenza, SARS-CoV-2, PrEP, PEP, chronic tx to supress viral load in Hep B, c, HIV inf. **C** increased bronchospasm risk with inhaled zanamvir in asthma and copd. NNRTI and protease inhibitor are contra in acute porphyria. Cuation with QT prolongation. **R** PO, inhaled, **A** GI upset, skin reactions, dizziness, and sleep problems. Inhaled zanamivir may cause bronchospasm. Immune-mediated effects include hypersensitivity. Long-term treatment can cause dyslipidaemia, hyperglycaemia, hypertension, and weight gain, increasing cardiovascular risk.

Answer 63

**M** Muscle, nerve, and bone function, Blood clotting Calcium homeostasis is primarily regulated by: Parathyroid hormone and vitamin D, which: Increase intestinal calcium absorption Enhance renal calcium reabsorption Promote bone resorption Impaired phosphate excretion and reduced vitamin D activation cause: Hyperphosphataemia Hypocalcaemia Calcium raises myocardial threshold potential, reducing excitability and arrhythmia risk (does not lower potassium) **I** Osteoporosis for calcium balance, CKD to tx and prevent 2' hyperparathyroidism and renal osteodystrophy, severe hyperkalaemia, calcium in hypocalcaemia, vit d in vit d deficiency **C**. Also reduces the absorption of many drugs, including iron, bisphosphonates, tetracyclines, and levothyroxine **avoid in hypercalcaemia** **R** PO calcium salt dissolves in stomach, calcium gluconate IV **A** may cause dyspepsia and constipation. When administered IV for the treatment of hyperkalaemia, calcium gluconate can cause hypotension and local tissue injury if subcut ## Footnote Administered IV, calcium must not be allowed to mix with ✖ sodium bicarbonate due to the risk of precipitation.

Answer 64

**M** Via **β1-adrenoreceptors,** which are located mainly in the heart, β-blockers reduce force of cardiac contraction and speed of conduction. In AF, it reduces ventricular rate by prolonging the refractory period of the atrioventricular (AV) node. In thyrotoxicosis, they offset the effect of β-adrenoreceptor upregulation, which causes symptoms such as tremor and palpitations. **I** IHD to improve angina and acs, chronic HF to improve prognosis, AF reduce ventricular rate, SVT restore sinus, resistant hypertension, prophylaxis of migraine, thyrotoxicosis **C** ✖ asthma, β-blockers can cause life-threatening bronchospasm and should be avoided. ▲ heart failure, β-blockers should be started at a low dose and increased slowly. contraindicated in ✖ heart block and severe ✖ hypotension must not be used with ✖ non-dihydropyridine calcium channel blockers **R** PO,IV **A** Fatigue, cold extremities, headache, and GI upset are common. β-blockers can also cause sleep disturbance, nightmares, and impotence.

Answer 65

**M** Redue bone turnover by inhibiting osteoclasts, also inhibits osteoclasts and promote apoptosis **I** Alendronic acid and risedronate sodium are first line for osteoporotic fragility fractures Pamidronate and zoledronic acid are used in severe hyperclacaemia of malignancy Myeloma and breast cacncer with bone mets First line in metbaolically active pagets disease **C** Avoid in severe renal impairement, contra in hypocalaemia. PO contra in active upper GI disorders, CARE in smokers and people witg major dental disease as risk of jaw osteonerosis absorption is reduced if taken with calcium salts (including milk), as well as antacids and iron salts **R** PO, IV slow **A** oesophagitis, hypophosphataemia. Osteonecrosis of teh jaw liekly wiht high dose IV therapy. Atypical femoral fracture in long-term Tx

Answer 66

**M** **Broad spectrum** Cephalosporins and carbapenems are naturally more resistant to β-lactamases than penicillins. Inhibit enzymes responsible for cross-linking peptidoglycans in bacterial cell walls **I** PO 2nd and 3rd line for UTI, pneumonia and other RTI. Parenteral for severe, complicated or Abx resistant infections. **C** Caution in those at risk of C Diff, elderly and hospital. Allergy of β lactam. Reduce dose in renal impairment Enhance the anticoagulant effect of warfarin by killing flora for Vit K. **R** PO, IV **A** GI upset ommon. Disrupt of flora -> C Diff overgrowth with toxin and Abx associated olitis. Hypersensitivity reaction. Rarely in parenteral, cause seizures.

Answer 67

**M** **Broad spectrum** binds to bacterial ribosomes inhibiting protein synthesis= bacteriostatic. **I** Bacterial conjunctivitis eye drops or ointment, ear drops for otitis externa. **C** contraindicated in people with previous ✖ hypersensitivity reactions or a personal or family history of ✖ bone marrow disorders. Systemic chloramphenicol is contraindicated in the ✖ third trimester of pregnancy, ✖ breastfeeding, and ✖ children < 2 years because of the risk of grey baby syndrome **R** Optic and Otic drops (different formula do not mix) **A** Stinging, burning, itching, Dose-related bone marrow suppression is more likely with high-dose therapy, Systemic- aplastic anaemia is rare. Grey baby syndrome. Optic and peripheral neuritis. ## Footnote Systemic (oral or IV) chloramphenicol is rarely used due to toxicity. In the UK, it is restricted to the treatment of life-threatening infection (Haemophilus influenzae) and typhoid fever (Salmonella spp.).

Answer 68

**M** Gram positive aerobes. binds to bacterial ribosomes and inhibits the early stages of bacterial protein synthesis. bacteriostatic **I** topical for acne vulgaris and vaginal for bacterial vaginosis, PO or parenteral for cellulitis, osteomyelitis, septic arthritis, intraabdo inf. Tx plasmodium falciparum malaria w quinine **C** Hx of hypersensitivity to clindamycin, caution in IBS, avoid in acute porphyria Enhanes neuromuscular blockers **R** PO, PV, IM,IV **A** diarrhoea, abdo pain, skin rash, abdnormal liver enzymes, Abx associated collitis, RARE- blood dyscrasias, SJS, DRESS ## Footnote useful option where penicillin is contraindicated by allergy, as there is no cross-sensitivity between these drug classes

Answer 69

**M** Ascending limb inhibit Na+/K+/2Cl− co-transporter. **I** relief of breathlessness in acute pulmonary oedema, Tx of fluid overload in CHF, Tx of fluid overload in other oedmatous states eg) renal disease, liver failure. **C** Lithium increased due to reduced excretion and risk of digoxin toxicity. Increase ototoxicity and nephrotoxicity of aminoglycosides Contra in severe hypovolaemia and dehydration. Caution in hypokalameia, hyponatraemia and risk of hepatic encephalopathy. Worsens gout **R** PO, IV **A**Deydration and hypotension, low electrolyte states. At high doses can effect endolymph w hearing loss and tinnitus

Answer 70

**M** Treatment seeks to increase dopaminergic stimulation to the striatum. D2 doesnt cross BBB so LDopa precursor enters via membrane transporter. Ropinirole and pramipexol are relatively selective agonists for the D2 receptor, **I** Improve motor sympx in Parkison's Disease. Levodopa is preferred if motor sympx impacting QOL. Options for Secondary parkinsonism **C** Caution in older people and those with existing cognitive or psychiatric disease due to risk of confusion and hallucinations. Caution in CVD as risk of hypotension **R** PO Modified release for on-off effect **A** Nausea and hypotension, sleepiness confusion and hallucinations Dyskinesias more problematic with levodopa and wearing off effect.

Answer 71

**M** replace water content in dry skin by reducing water loss **I** dry or scaling skin disorders- emollient can be used in combo w topical corticosteroids for eczema. Can reduce dryness and cracking in psoriasis **C** paraffin-based emollients are a significant fire hazard. when using more than one topical product, applications should be separated in time **R** Topical. semi-solid creams (50% oil, 50% water), semi-liquid lotions (less oil, more water) or ointments (80% oil, 20% water) **A** greasiness of the skin Emollient ointments can exacerbate acne vulgaris and folliculitis by blocking pores

Answer 72

**M** Related to γ-aminobutyric acid (GABA), the major inhibitory neurotransmitter in the brain but DO NOT BIND. ? inhibition of pre-synaptic VGCaC neocortex and hippocampus. **I** Neuropathic pain, prevention of focal seizures, GAD **C** doses should be reduced in ▲ renal impairment. identify risk factors for ▲ substance misuse. sedative effects of gabapentinoids may be enhanced when combined with other ▲ sedating drug **R** PO **A** drowsiness, impaired concentration, dizziness, and ataxia, Weight gain, recognised as drugs of misuse and dependency ## Footnote Gabapentin may cause false-positive results for detection of protein on urine dipstick testing

Answer 73

**M** relatively narrow spectrum of activity against Gram-positive bacteria inhibit growth and cross-linking of peptidoglycan chain= bacteriocidal **I** complicated skin and soft tissue, bone and joint infections, infective endocarditis, Vancomycin is a first-line treatment for Clostridioides difficile colitis. **C** caution in people with ▲ immune-mediated hypersensitivity, risk in ▲ hearing impairment. ▲ reduced renal function, including ▲ neonates and ▲ older adults, are at increased risk of nephrotoxicity. Ototoxicity and/or nephrotoxicity when prescribed with other drugs that cause these effects, particularly ▲ loop diuretics, ▲ aminoglycosides, ▲ NSAIDs, and ▲ ciclosporin **R** parenterally, vancomycin PO **A** Pain and thrombophlebitis from vancomycin infusion are common. vancomycin flushing syndrome. cause nephrotoxicity and ototoxicity Rare: blood dyscrasias (neutropenia, thrombocytopenia) and severe cutaneous adverse reactions.

Answer 74

**M** reduce gastric acid secretion via H2 receptor antagonists, but cannot completely suppress gastric acid production **I** Peptic ulcer disease where PPI inadequate. GORD and Dyspepsia where PPI inadequate **C** Dose reduced in renal impaired, Can mask GORDor ulcer diseasde. Inhibits cyp P450 so interacts with ▲ aminophylline/theophylline, ▲ amiodarone, ▲ citalopram, ▲ phenytoin, ▲ quinine, and ▲ warfarin **R** PO w food **A** Side effects are usually mild and include bowel disturbance (diarrhoea or, less often, constipation), headache, and dizziness. ## Footnote At the time of writing, ranitidine is unavailable due to safety concerns as products have been found to contain low levels of an impurity called N-nitrosodimethylamine, a substance that could cause cancer

Answer 75

**M** . Antithrombin inactivates clotting factors, particularly factors IIa (thrombin) and Xa, providing a natural break to the clotting process. Heparins and fondaparinux enhance the anticoagulant effect of antithrombin unfractionated heparin (UFH) promotes inactivation of both factors IIa and Xa, whereas LMWH is more specific for factor Xa **I** LMWH (preferred) prevention of VTE. acute coronary syndrome (ACS) to reduce clot progression. **C** ▲ clotting disorders and ▲ severe uncontrolled hypertension. withheld immediately before and after ▲ invasive procedure. ▲ renal impairment, LMWH and fondaparinux accumulate **R** SC, IV **A** haemorrhage, Bruising, Hyperkalaemia occurs occasionally, due to an effect on adrenal aldosterone secretion. RARE: (heparin-induced thrombocytopenia (HIT) less likely with LMWH than UFH

Answer 76

**M** * Tamoxifen is a selective oestrogen receptor modulator * Anastrozole and letrozole are aromatase inhibitors * 90-percent of prostate cancers will respond to hormone therapies that suppress androgens * Androgen receptor inhibitors like bicalutamide directly block androgen **I** Tamoxifen, anastrozole, and letrozole are used in estrogen (oestrogen)-receptor positive (ER-positive) breast cancer, as an adjuvant (after surgery) Leuprorelin, bicalutamide, and goserelin are used in prostate cancer, **C** Tamoxifen is contraindicated in ✖ pregnancy and ✖ breastfeeding. Aromatase inhibitors should not be used in ✖ pre-menopausal women Initial overstimulation of LH production by goserelin and leuprorelin may stimulate tumour growth **R** Tamoxifen, bicalutamide, and aromatase inhibitors PO. GnRH analogues may be formulated as implants or suspension for injection SC or IM **A** are symptoms of oestrogen depletion (e.g. vaginal dryness, hot flushes, loss of bone density) Tamoxifen increases the risk of venous thromboembolism and endometrial cancer. agranulocytosis and liver failure. Antiandrogen therapy may lead to hair loss, gynaecomastia, and mood disturbance. ## Footnote Tamoxifen inhibits a cytochrome P450 enzyme (CYP2C9) responsible for metabolising ✖ warfarin, increasing the risk of bleeding. The selective serotonin reuptake inhibitors (SSRIs) ✖ fluoxetine, and ✖ paroxetine inhibit hepatic activation of tamoxifen

Answer 77

**M** functions similarly to endogenous insulin Insulin also activates Na+/K+-ATPase, driving K+ into cells, and reducing serum K+ concentrations **I** insulin replacement in type 1 diabetes, and control of blood glucose in type 2 diabetes IV, in the Tx of diabetic emergencies such as diabetic ketoacidosis and hyperosmolar hyperglycaemic state, and for peri-operative glycaemic control Tx Hyperkalaemia, with IV glucose. **C** ▲ renal impairment, insulin clearance is reduced, so there is an increased risk of hypoglycaemia. therapy with systemic corticosteroids increases insulin requirements. **R** SC or smart pumps **A** hypoglycaemia, insulin can cause fat overgrowth (lipohypertrophy),

Answer 78

**M:** replenish iron for erythropoesis. Is absorbed best in **Fe2**+ state in **duodenum** and **jejenum**. Vit C increases absorption. Transferrin transports **I:** Iron deficiency anaemia, prophylaxis. **C:** Reduce absoprtion of levothyroxine and bisphosphonates. May exacerbate bowel symptoms in intestinal disease. Caution in atopic predisposition for anaphylaxis risk **R:** IV or PO. IV so correction and in end-stage renal disease w/ erythropoeitin **A:**GI upset, incl nausea, epigastric pain, constipation, diarrhoea. Black stool ## Footnote Ferrous sulfate 200 mg contains 65 mg elemental iron. Ferrous Fumarate 200mg contains 60mg of Iron

Answer 79

Ferinject 50 mg iron/mL dispersion for injection/infusion. One mL of dispersion contains ferric carboxymaltose corresponding to 50 mg iron. – there is a clinical need to deliver iron rapidly. Iron deficiency occurring in the first trimester of pregnancy can in many cases be treated with oral iron. Treatment with Ferinject should be confined to the second and third trimester if the benefit is judged to outweigh the potential risk for both the mother and the foetus.

Answer 80

**M:** Voltage sensitive neuronal Na+ channels producing Na+ influx. Impedes repetitive neuronal firing. **I:** seizure prophylaxis in epilepsy. First line monotherapy or add on in focal seizures and generalised tonic-clonic For bipolar depression **C** * avoid in people with a prior history of ▲ hypersensitivity to other antiepileptic drugs. * metabolised by hepatic glucuronidation, so dosage reduction in ▲ hepatic impairment. * Drugs that induce glucuronidation include ▲ carbamazepine, ▲ phenytoin, ▲ oestrogens, ▲ rifampicin, and ▲ protease inhibitors * Glucuronidation is inhibited by ▲ valproate, causing lamotrigine concentration to rise **R:** PO standard swallow w water whole but chewable/ dispersible forms too. **A:** headache, drowsiness, irritability, blurred vision, dizziness, and GI upset. A minority develop a skin rash within a few weeks ## Footnote Lamotrigine appears to be unique among agents used in bipolar disorder, in that it effectively treats depressive symptoms but does not increase the risk of a switch to mania.

Answer 81

**M** Osmotic laxatives substances remain in gut lumen to move water in to lumen and stimulate peristalsis * macrogol 3350 is a non-absorbable polymer of ethylene glycol * Lactulose has a useful additional effect of reducing ammonia absorption by increasing gut transit rate and acidifying the stool **I:** Constipation, bowel prep for surgery/endoscopy. Hepatic encephalopathy (lactulose reduce ammonia) **C** contraindicated in ✖ intestinal obstruction as there is a risk of perforation. **R** Oral solutions can be taken as they are or diluted in another liquid; powdered forms are dissolved in water. **Macrogols must not be administered** with feeds that contain a **starch**-based thickener **A** Flatulence, abdominal cramps, diarrhoea, and nausea

Answer 82

**M** * increase water and electrolyte secretion from the colonic mucosa, thereby increasing the volume of colonic content and stimulating peristalsis. * direct pro-peristaltic action, * bacterial metabolism of senna in the intestine produces metabolites that have a direct action on the enteric nervous system, stimulating peristalsis. **I:** Constipation **C** contraindicated in ✖ intestinal obstruction as there is a risk of perforation. **R** Oral solutions can be taken as they are or diluted in another liquid; powdered forms are dissolved in water. **A** Flatulence, abdominal cramps, diarrhoea, and nausea

Answer 83

**M** * glycerol is osmotic laxative with lubricant and faecal dotening effects with mild irritant effect on rectal mucosa with stimulates peristalsis. **I:** Constipation, faecal impaction, bowel preparation, hepatic encephalopathy (lactulose) **C** Phosphates enemas can cause **significant** **fluid** **shifts**, so should be used with caution in ▲ heart failure, ▲ ascites and when ▲ electrolyte disturbances are present. **R** Enemas and suppositories are generally used when there is constipation complicated by faecal impaction **A** Flatulence, abdominal cramps, diarrhoea, and nausea. * Enemas in particular can be uncomfortable because of the relatively large volume that must be instilled into the rectum. * Phosphates enemas can cause pain, volume depletion (leading to hypotension), and electrolyte disturbances, including hyperphosphataemia and hyper- or hypokalaemia.

Answer 84

**M:** In asthma, LT produced by mast cells and eosinophils active receptor CysLT1 -> inflammation and bronchoconstriction. BLOCKS the CysLT1 so dampens inflammatory cascade. **I** Add on for chronic asthma, allergic chinitis in those who have asthma and nasal symptoms have not responded to antihistamines etc. **C** Drugs that induce the cytochrome P450 enzymes that metabolise montelukast can cause a reduction in plasma levels **R** PO **A** Headache, abdominal pain, and GI upset. Neuropsychiatric reactions, including sleep disturbance, depression, and agitation occur in up to 1 in 100 of those taking montelukast.

Answer 85

**M** * broad spectrum of activity against Gram-positive and some Gram-negative organisms * inhibit bacterial protein synthesis * bacteriostatic **I** resp, skin, soft tissue infectio when penicillin contraindicated. Added to penicillin in severe pneumonia to cover atypical, Eradication of h pylori **C** * ✖ macrolide hypersensitivity, * Caution in ▲ severe hepatic impairment, and doses should be reduced in ▲ severe renal impairment. * Erythromycin and clarithromycin (but not azithromycin) inhibit cytochrome P450 (CYP) enzymes so caution for warfarin. * Also caution ▲ drugs that prolong the QT interval or cause arrhythmias, **R** PO or IV (dilute in large water) NEVER IV bolus or IM (irritant) **A** , causing nausea, vomiting, abdominal pain, and diarrhoea. IV thrombophlebitis

Answer 86

**M** * anaerobic bacteria and protozoa * passive diffusion, generates nitroso free radicals, binds to DNA, damage **I:** oropharyngeal Gram-negative anaerobes, including dental infections, infected human/animal bites and aspiration pneumonia. Eradicate Hpylori, Intraabdominal inf and PID, protozoa incl trichomonal vaginal inf and giardiasis, C diff if IV **C** inhibitory effect on CYP enzymes, reducing metabolism of warfarin dose should be reduced in ▲ severe liver disease. Avoid alcohol as inhibits acetaldehyde dehydrogenase. **R** PO preferred but IV for severe, PR is available. Can be topical for bacteria vaginosis etc. **A** GI upset (such as nausea, vomiting, metallic taste) and immediate and delayed hypersensitivity reaction High dose: peripheral and optic neuropathy, seizures, and encephalopathy.

Answer 87

**M** NO increases cyclic guanosine monophosphate (cGMP) synthesis and reduces intracellular Ca2+ in vascular smooth muscle cells, causing them to relax and ARTERIAL VASOCILATION. Reduces preload. **I** short- ACS acute angina. long- prophylaxis of angina where Bblocker. CCB are insufficient. IV for ACS, pulmonary oedema, and hypertensive emergencies **C** ✖ severe aortic stenosis, Nitrates should be avoided in ✖ hypotension. ✖ phosphodiesterase (PDE) inhibitors (e.g. sildenafil) as acts on metabolising cGMP **R** GTN spray, IV infusion, immediate release tablets. **A** flushing, headaches, light-headedness, and hypotension

Answer 88

**M** * **Cramp**: reducing the excitability of the motor end plate in response to acetylcholine stimulation. * **Malaria**: detox cant occur so haem monomers accumulate, impairing membrane integrity and killing the parasites in the schizont stage **I** Nocturnal leg cramps, first line for malaria P. falciparum **C** caution in people with existing ▲ hearing or visual loss. It is teratogenic, so should not be used in the ▲ first trimester of pregnancy, avoid in G6PD deficiency (haemolysis) **R** PO, IV slow infusion, **A** tinnitus, deafness and blindness (which may be permanent), GI upset, and hypersensitivity reactions. Quinine prolongs the QT

Answer 89

**M** * Broad spectrum G- and G+ * Ciprofloxacin= Pseudomonas aeruginosa * Moxi and Levo enhanced G+ activity * inhibiting DNA synthesis **I:** UTI (G-), Severe gastroenteritis (shigella, campylobacter), LRTI incl IECOPD, Pneumonia **C** calcium, iron, antacids reduce absorption and efficacy Ciprofloxacin inhibits certain cytochrome P450 (CYP) enzymes, increasing risk of toxicity ▲ drugs that prolong the QT interval Co-prescription of ▲ NSAIDs increases the risk of seizures ▲ prednisolone increases the risk of tendon rupture **R** PO and IV (over 60min) **A** GI upset and immediate- and delayed-type hypersensitivity, Clostridioides difficile colitis

Answer 90

**M:** synaptic vesicle protein 2A (SV2A) expressed in excitatory and inhibitory synases. inhibits synchronised epileptiform burst firing and reduces propagation of seizure activity. **I** Seizure prophylaxis in epilepsy. Levetiracetam is increasingly the preferred option for treating established convulsive status epilepticus, following inadequate response to a benzodiazepine. **C** ▲ renal impairment. ▲ hepatic impairment. Brivaracetam has potential to interact with cytochrome P450 inducers **R** PO, IV (15 min) **A** Drowsiness (affecting about 10%), weakness, dizziness, and headache are the most common adverse effects. Mood disturbance. Suicidal ideation and serious hypersensitivity reactions have been reported rarely.

Answer 91

**M** Triptans are thought to act by inhibiting neurotransmission in the peripheral trigeminal nerve and in the trigeminocervical complex (via 5-HT1B and 5-HT1D receptors) and constricting cranial blood vessels (via 5-HT1B receptors). **I** In acute migraines to reduce duration and symptoms. **C** Vasoconstriction: ✖ ischaemic heart disease, ✖ cerebrovascular disease, ✖ peripheral vascular disease, and ✖ uncontrolled hypertension. Triptans should also not be used in ✖ hemiplegic migraine or ✖ migraine with brainstem aura. may increase the risk of serotonin toxicity and serotonin syndrome when given in combination with other serotonergic drugs **R** Tablets, nasal spray **A**chest and throat discomfort, angina and myocardial infarction due to coronary vasospasm, nausea and vomiting, tiredness, dizziness, and transient high blood pressur

Answer 92

**M** Stimulate an adaptive immune response by exposing the immune system to an antigen, leading to memory cell formation for future protection. **I**: Prevention of infectious diseases (e.g., MMR, DTP, HPV, influenza). **C**: Severe allergic reaction (anaphylaxis) to a previous dose or component, immunocompromised states for live vaccines, pregnancy for certain live vaccines (e.g., MMR, varicella). **R**: Intramuscular (e.g., DTP, HPV), subcutaneous (e.g., MMR, varicella), oral (e.g., rotavirus), intranasal (e.g., live attenuated influenza vaccine). **A**: Local site reactions (pain, swelling, redness), fever, mild systemic symptoms, rare serious reactions (e.g., anaphylaxis, Guillain-Barré syndrome).

Answer 93

**M** Provides passive immunity by supplying pre-formed antibodies that neutralize pathogens or modulate immune function. **I**: Immune deficiency disorders (e.g., primary immunodeficiency, hypogammaglobulinemia), autoimmune conditions (e.g., Kawasaki disease, immune thrombocytopenic purpura), post-exposure prophylaxis (e.g., hepatitis A, measles in immunocompromised patients). **C**: IgA deficiency with anti-IgA antibodies (risk of anaphylaxis), hypersensitivity to human immunoglobulin. **R**Intravenous (IV) or subcutaneous (SC). **A**Headache, fever, chills, infusion-related reactions, thromboembolic events, hemolysis, renal impairment.

Answer 94

**M**: Provides passive immunity by neutralizing tetanus toxin, preventing disease progression. **I**: Post-exposure prophylaxis for tetanus-prone wounds (e.g., deep, contaminated wounds in unvaccinated or incompletely vaccinated individuals). **C**: Hypersensitivity to human immunoglobulin, IgA deficiency with anti-IgA antibodies. **R**: Intramuscular (IM). **A**: Local injection site reactions, fever, rare anaphylaxis.

Answer 95

**M** selectively and reversibly inhibit the sodium–glucose co-transporter 2 (SGLT2) in the proximal convoluted tubule of the nephron. SGLT2 inhibition impairs glucose reabsorption in the nephron, increasing renal excretion of glucose (glycosuria) and treating hyperglycaemia **I** T2DM, symptomatic chronic inadequately controlled HFrEF, CKD w albuminuria w ACEi/ARB **C** withheld during ▲ intercurrent illness that causes or presents a risk of ✖ volume depletion or hypotension. augment the effects of other glucose-lowering drug **R** Canagliflozin and dapagliflozin are formulated as tablets. **A** Osmotic diuresis can cause thirst and, in the context of intercurrent illness, increase the risk of hypovolaemia and electrolyte disturbance Increased risk of UTI and genital infection. Rare ketoacidosis w normal glucose (mainly T1DM)

Answer 96

**Azoles**: Hepatotoxicity, QT prolongation, drug interactions. **Echinocandins**: Generally well tolerated, rare liver toxicity. **Polyenes** (Amphotericin B): Nephrotoxicity, electrolyte disturbances (hypokalemia, hypomagnesemia). **Terbinafine**: GI upset, liver toxicity (monitor LFTs).

Answer 97

**M** **Anticholinergic**; blocks **muscarinic** receptors in the CNS, reducing cholinergic activity. **I** Parkinson’s disease, drug-induced extrapyramidal symptoms (e.g., from antipsychotics). **C**: Narrow-angle glaucoma, urinary retention, GI obstruction. **R**: Oral, IM. **A**: Dry mouth, blurred vision, urinary retention, confusion, tachycardia, raised intraocular pressure.

Answer 98

**M** Partial **agonist** at D2 and 5-HT**1**A receptors, **antagonist** at 5-HT**2**A receptors. **I**: Schizophrenia, bipolar disorder, adjunct in major depressive disorder. **C**: Hypersensitivity, caution in elderly with dementia (↑ stroke risk), liver impairment **R**: Oral, IM (long-acting depot available). **A** Akathisia, weight gain, insomnia, nausea, headache, QT prolongation (rare). ***PARKINSONISM***