Miscellaneous Pharmacology

Question 1

Tricyclic Antidepressant Overdose eg. amitriptyline

Answer 1

Early features relate to anticholinergic properties: dry mouth, dilated pupils, agitation, sinus tachycardia, blurred vision.

Features of severe poisoning include:
arrhythmias
seizures
metabolic acidosis
coma

ECG changes include:
sinus tachycardia
widening of QRS
prolongation of QT interval

Widening of QRS > 100ms is associated with an increased risk of seizures whilst QRS > 160ms is associated with ventricular arrhythmias

Management;

Management
IV bicarbonate- first-line therapy for hypotension or arrhythmias/ indications include widening of the QRS interval >100 msec or a ventricular arrhythmia
other drugs for arrhythmias
NB- intravenous lipid emulsion is increasingly used to bind free drug and reduce toxicity/ dialysis is ineffective in removing tricyclics

Question 2

Paracetamol Overdose

Answer 2

Increased risk of hepatotoxicity;
patients taking liver enzyme-inducing drugs (rifampicin, phenytoin, carbamazepine, chronic alcohol excess, St John’s Wort)
malnourished patients (e.g. anorexia nervosa) or patients who have not eaten for a few days
NB- acute alcohol intake is better than chronic alcohol excess (may be protective)

The minority of patients who present within 1 hour may benefit from activated charcoal to reduce absorption of the drug.

Acetylcysteine should be given if:
there is a staggered overdose* or there is doubt over the time of paracetamol ingestion, regardless of the plasma paracetamol concentration; or patients who present 8-24 hours after ingestion of more than 150mg/kg of paracetamol (otherwise, wait for paracetamol levels to return)

Acetylcysteine is now infused over 1 hour (rather than the previous 15 minutes) to reduce the number of adverse effects. Acetylcysteine commonly causes an anaphylactoid reaction (non-IgE mediated mast cell release). Anaphylactoid reactions to IV acetylcysteine are generally treated by stopping the infusion, then restarting at a slower rate.

When to give acetylcysteine 24 hours after ingestion;
The patent is clearly jaundiced
The patient has hepatic tenderness
The ALT is above the upper limit of normal
The INR is greater than 1.3
The paracetamol concentration is detectable

Liver transplant criteria;
Arterial pH < 7.3, 24 hours after ingestion

or all of the following:
prothrombin time > 100 seconds
creatinine > 300 µmol/l
grade III or IV encephalopathy

Question 3

Drug induced liver disease

Answer 3

The following drugs tend to cause a hepatocellular picture:
paracetamol
sodium valproate, phenytoin
MAOIs
halothane
anti-tuberculosis: isoniazid, rifampicin, pyrazinamide
statins
alcohol
amiodarone
methyldopa
nitrofurantoin

The following drugs tend to cause cholestasis (+/- hepatitis):
combined oral contraceptive pill
antibiotics: flucloxacillin, co-amoxiclav, erythromycin*
anabolic steroids, testosterones
phenothiazines: chlorpromazine, prochlorperazine
sulphonylureas
fibrates
rare reported causes: nifedipine

Liver cirrhosis
methotrexate
methyldopa
amiodarone

Question 4

Diclofenac

Answer 4

Diclofenac is now contraindicated with any form of cardiovascular disease

Question 5

Tetracycline SE

Answer 5

associated with sensitivity to light

Question 6

Ciprofloxacin

Answer 6

Ciprofloxacin is contraindicated in G6PD deficiency

Question 7

Heparin

Answer 7

Unfractionated, ‘standard’ heparin or low molecular weight heparin (LMWH) eg. fondaparinux/enoxaparin. Both activate antithrombin III

Adverse effects of heparins include:
-bleeding
-thrombocytopenia (HIT)
-osteoporosis and an increased risk of fractures
-hyperkalaemia - this is thought to be caused by inhibition of aldosterone secretion

Unfractionated/Standard heparin
-IV
-Short acting
-Activates antithrombin III. Forms a complex that inhibits thrombin, factors Xa, IXa, Xia and XIIa
-Requires monitoring: APTT
-Useful in situations where there is a high risk of bleeding as anticoagulation can be terminated rapidly. Also useful in renal failure

LMWH
-S/C
-Long acting
-Activates antithrombin III. Forms a complex that inhibits factor Xa
-Routine monitoring not required (although Anti-Factor Xa can be used)

Heparin overdose may be reversed by protamine sulphate, although this only partially reverses the effect of LMWH.

Question 8

Warfarin: management of high INR

Answer 8

INR 5.0-8.0
No bleeding
-Withhold 1 or 2 doses of warfarin
-Reduce subsequent maintenance dose

INR 5.0-8.0
Minor bleeding
-Stop warfarin
-Give intravenous vitamin K 1-3mg
-Restart when INR < 5.0

INR > 8.0
No bleeding
-Stop warfarin
-Give vitamin K 1-5mg by mouth, using the intravenous preparation orally
-Repeat dose of vitamin K if INR still too high after 24 hours
-Restart when INR < 5.0

INR > 8.0
Minor bleeding
-Stop warfarin
-Give intravenous vitamin K 1-3mg
-Repeat dose of vitamin K if INR still too high after 24 hours
Restart warfarin when INR < 5.0

Major bleeding (Any INR)
-Stop warfarin
-Give intravenous vitamin K 5mg
-Prothrombin complex concentrate - if not available then FFP*

Question 9

SSRI and NSAID

Answer 9

Give a PPI

Question 10

Beta blockers and acute heart failure

Answer 10

in acute heart failure with the presence of either a heart rate<50 beats/min, 2nd or 3rd-degree AV block, or shock, beta-blockers should be stopped.

Question 11

Certain antiemetics to avoid in certain situations

Answer 11

Cyclizine is a H1-receptor antagonist that acts by blocking histamine receptors in the CTZ. It is safe to use in pregnancy. However, cyclizine can cause a drop in cardiac output and an increase in heart rate. For this reason, caution should be employed in patients with severe heart failure.

Dopamine antagonists, such as metoclopramide, are pro-kinetics and should therefore be avoided in intestinal obstruction. Dopamine antagonists should also be used with caution in patients with Parkinson’s disease.

Question 12

DOAC’s/NOAC’s in Pregnancy

Answer 12

Contraindicated- use LMWH instead

Question 13

IM Carboprost (uterine atony)

Answer 13

Avoid in asthmatics

Question 14

Mirtazapine

Answer 14

Antidepressant that causes weight gain
Fluoxetine- antidepressant that causes weight loss

Question 15

Adrenaline doses

Answer 15

anaphylaxis: 0.5ml 1:1,000 IM

cardiac arrest: 10ml 1:10,000 IV or 1ml of 1:1000 IV

Management of accidental injection- local infiltration of phentolamine

Question 16

Problematic drinking management

Answer 16

disulfiram- unpleasant reaction. Don’t use in IHD/psychosis

acamprosate- reduces craving, known to be a weak antagonist of NMDA receptors

Question 17

Allopurinol

Answer 17

works by inhibiting xanthine oxidase

Commencement of ULT is best delayed until inflammation has settled as ULT is better discussed when the patient is not in pain

urate-lowering therapy to all patients after their first attack of gout

adverse derm effects

interacts with- azathioprine, theophylline, cyclophosphamide

Question 18

Alpha blockers and cataracts

Answer 18

Caution should be exercised in patients who are having cataract surgery due to the risk of intra-operative floppy iris syndrome

Question 19

Amiodarone

Answer 19

Adverse effects of amiodarone use
thyroid dysfunction: both hypothyroidism and hyper-thyroidism
corneal deposits
pulmonary fibrosis/pneumonitis
liver fibrosis/hepatitis
peripheral neuropathy, myopathy
photosensitivity
‘slate-grey’ appearance
thrombophlebitis and injection site reactions
bradycardia
lengths QT interval

Important drug interactions of amiodarone include:
decreased metabolism of warfarin, therefore increased INR
increased digoxin levels

Question 20

Aspirin

Answer 20

Aspirin works by blocking the action of both cyclooxygenase-1 and 2. (non reversible)
Cyclooxygenase is responsible for prostaglandin, prostacyclin and thromboxane 2 synthesis.

Question 21

Beta blocker overdose

Answer 21

Management
if bradycardic then atropine
in resistant cases glucagon may be used

Haemodialysis is not effective in beta-blocker overdose

Question 22

Dihydropyridines

Answer 22

Nifedipine, amlodipine, felodipine

Affects the peripheral vascular smooth muscle more than the myocardium and therefore do not result in worsening of heart failure but may therefore cause ankle swelling

SE’s- Flushing, headache, ankle swelling

Non-dihydropyridines can cause heart failure/bradycardia/hypotension (and constipation-verapamil)

Question 23

Ciclosporin

Answer 23

nephrotoxicity
hepatotoxicity
fluid retention
hypertension
hyperkalaemia
hypertrichosis
gingival hyperplasia
tremor
impaired glucose tolerance
hyperlipidaemia
increased susceptibility to severe infection

Question 24

Cocaine

Answer 24

cocaine blocks the uptake of dopamine, noradrenaline and serotonin

Many SE’s during toxicity but some to remember;
both tachycardia and bradycardia may occur
hypertension
QRS widening and QT prolongation
aortic dissection
ischaemic colitis
hyperthermia
metabolic acidosis
rhabdomyolysis

Mx- benzodiazpines (GTN for chest pain, sodium nitroprusside for HTN), no beta blockers

Question 25

Diclofenac contraindications

Answer 25

ischaemic heart disease peripheral arterial disease cerebrovascular disease congestive heart failure (New York Heart Association classification II-IV)

Question 26

Digoxin and toxicity

Answer 26

Monitoring digoxin level is not monitored routinely, except in suspected toxicity if toxicity is suspected, digoxin concentrations should be measured within 8 to 12 hours of the last dose Precipitating factors classically: hypokalaemia digoxin normally binds to the ATPase pump on the same site as potassium. Hypokalaemia → digoxin more easily bind to the ATPase pump → increased inhibitory effects increasing age renal failure myocardial ischaemia hypomagnesaemia, hypercalcaemia, hypernatraemia, acidosis hypoalbuminaemia hypothermia hypothyroidism drugs: amiodarone, quinidine, verapamil, diltiazem, spironolactone, ciclosporin. Also drugs which cause hypokalaemia e.g. thiazides and loop diuretics

Question 27

Urticaria

Answer 27

aspirin penicillins NSAIDs opiates

Question 28

Drug-induced impaired glucose tolerance

Answer 28

thiazides, furosemide (less common) steroids tacrolimus, ciclosporin interferon-alpha nicotinic acid antipsychotics Beta-blockers cause a slight impairment of glucose tolerance. They should also be used with caution in diabetics as they can interfere with the metabolic and autonomic responses to hypoglycaemia

Question 29

Drug-induced thrombocytopenia

Answer 29

quinine abciximab NSAIDs diuretics: furosemide antibiotics: penicillins, sulphonamides, rifampicin anticonvulsants: carbamazepine, valproate heparin

Question 30

Drug-induced urinary retention

Answer 30

tricyclic antidepressants e.g. amitriptyline anticholinergics e.g. antipsychotics, antihistamines opioids NSAIDs disopyramide

Question 31

Drugs causing lung fibrosis

Answer 31

amiodarone cytotoxic agents: busulphan, bleomycin anti-rheumatoid drugs: methotrexate, sulfasalazine nitrofurantoin ergot-derived dopamine receptor agonists (bromocriptine, cabergoline, pergolide)

Question 32

Drugs causing ocular problems

Answer 32

steroids amiodarone indomethacin ethambutol amiodarone metronidazole chloroquine, quinine Sildenafil

Question 33

Drugs causing photosensitivity

Answer 33

thiazides tetracyclines, sulphonamides, ciprofloxacin amiodarone NSAIDs e.g. piroxicam psoralens sulphonylureas

Question 34

Ecstasy overdose

Answer 34

supportive dantrolene may be used for hyperthermia if simple measures fail

Question 35

Ethylene glycol toxicity

Answer 35

metabolic acidosis with high anion gap and high osmolar gap. fomepizole, an inhibitor of alcohol dehydrogenase, is now used first-line in preference to ethanol haemodialysis also has a role in refractory cases

Question 36

Finasteride

Answer 36

Indications benign prostatic hyperplasia male-pattern baldness Adverse effects impotence decrease libido ejaculation disorders gynaecomastia and breast tenderness Finasteride causes decreased levels of serum prostate-specific antigen

Question 37

Flecanide

Answer 37

Contraindications post myocardial infarction structural heart disease: e.g. heart failure sinus node dysfunction; second-degree or greater AV block atrial flutter Adverse effects negatively inotropic bradycardia proarrhythmic oral paraesthesia visual disturbances

Question 38

Gentamicin

Answer 38

both peak (1 hour after administration) and trough levels (just before the next dose) are measured Myasthenia gravis is a contraindication

Question 39

Hypomagnesia

Answer 39

drugs diuretics proton pump inhibitors total parenteral nutrition diarrhoea may occur with acute or chronic diarrhoea alcohol hypokalaemia hypercalcaemia Features may be similar to hypocalcaemia: paraesthesia tetany seizures arrhythmias decreased PTH secretion → hypocalcaemia ECG features similar to those of hypokalaemia exacerbates digoxin toxicity <0.4 mmol/L or tetany, arrhythmias, or seizures intravenous magnesium >0.4 mmol/l oral magnesium salts diarrhoea can occur

Question 40

Lithium toxicity

Answer 40

Toxicity may be precipitated by: dehydration renal failure drugs: diuretics (especially thiazides), ACE inhibitors/angiotensin II receptor blockers, NSAIDs and metronidazole. mild-moderate toxicity may respond to volume resuscitation with normal saline haemodialysis may be needed in severe toxicity

Question 41

Macrolides (erythromycin/clarithromycin/azithromycin)

Answer 41

Adverse effects prolongation of the QT interval gastrointestinal side-effects are common. Nausea is less common with clarithromycin than erythromycin cholestatic jaundice: risk may be reduced if erythromycin stearate is used P450 inhibitor (see below) azithromycin is associated with hearing loss and tinnitus Common interactions statins should be stopped whilst taking a course of macrolides. Macrolides inhibit the cytochrome P450 isoenzyme CYP3A4 that metabolises statins. Taking macrolides concurrently with statins significantly increases the risk of myopathy and rhabdomyolysis.

Question 42

Metformin

Answer 42

Contraindications chronic kidney disease: NICE recommend that the dose should be reviewed if the creatinine is > 130 µmol/l (or eGFR < 45 ml/min) and stopped if the creatinine is > 150 µmol/l (or eGFR < 30 ml/min) metformin may cause lactic acidosis if taken during a period where there is tissue hypoxia. Examples include a recent myocardial infarction, sepsis, acute kidney injury and severe dehydration iodine-containing x-ray contrast media: examples include peripheral arterial angiography, coronary angiography, intravenous pyelography (IVP); there is an increasing risk of provoking renal impairment due to contrast nephropathy; metformin should be discontinued on the day of the procedure and for 48 hours thereafter Starting metformin metformin should be titrated up slowly to reduce the incidence of gastrointestinal side-effects if patients develop unacceptable side-effects then modified-release metformin should be considered

Question 43

Organophosphate insecticide poisoning

Answer 43

Features Salivation Lacrimation Urination Defecation/diarrhoea cardiovascular: hypotension, bradycardia also: small pupils, muscle fasciculation Management atropine

Question 44

Overdose and poisoning page

Answer 44

Look at all the antidotes for all these poisons

Question 45

CP450 System

Answer 45

CRAP GPs induce SICKFACES.com to inhibit their clinical reasoning skills CRAP GPs can be used to easily remember common CYP450 inducers (reduced treatment efficacy) Carbemazepines Rifampicin Alcohol Phenytoin Griseofulvin Phenobarbitone Sulphonylureas The mnemonic SICKFACES.COM can be used to easily remember common CYP450 inhibitors (increased toxicity- builds up in blood) Sodium valproate Isoniazid Cimetidine Ketoconazole Fluconazole Alcohol & Grapefruit juice Chloramphenicol Erythromycin Sulfonamides Ciprofloxacin Omeprazole Metronidazole Common Interactions Exampled of drugs (substrates) that commonly interact with CYP450 enzyme inhibitors and inducers are; Warfarin the Combined Contraceptive Pill, Theophylline, Corticosteroids, Tricyclics, Pethidine, and Statins.

Question 46

Sildenafil

Answer 46

Side-effects visual disturbances blue discolouration non-arteritic anterior ischaemic neuropathy nasal congestion flushing gastrointestinal side-effects headache priapism nb- contraindicated by nitrates and nicorandil

Question 47

Drugs to avoid in pregnancy

Answer 47

Antibiotics tetracyclines aminoglycosides sulphonamides and trimethoprim quinolones: the BNF advises to avoid due to arthropathy in some animal studies Other drugs ACE inhibitors, angiotensin II receptor antagonists statins warfarin sulfonylureas retinoids (including topical) cytotoxic agents The majority of antiepileptics including valproate, carbamazepine and phenytoin are known to be potentially harmful. The decision to stop such treatments however is difficult as uncontrolled epilepsy is also a risk

Question 48

Quinolones (ciprofloxacin levofloxacin)

Answer 48

Adverse effects lower seizure threshold in patients with epilepsy tendon damage (including rupture) - the risk is increased in patients also taking steroids cartilage damage has been demonstrated in animal models and for this reason quinolones are generally avoided (but not necessarily contraindicated) in children lengthens QT interval Contraindications Quinolones should generally be avoided in women who are pregnant or breastfeeding avoid in G6PD

Question 49

Salicylate (aspirin) overdose

Answer 49

salicylate overdose leads to a mixed respiratory alkalosis and metabolic acidosis. Early stimulation of the respiratory centre leads to a respiratory alkalosis whilst later the direct acid effects of salicylates (combined with acute renal failure) may lead to an acidosis Features hyperventilation (centrally stimulates respiration) tinnitus lethargy sweating, pyrexia* nausea/vomiting hyperglycaemia and hypoglycaemia seizures coma Treatment general (ABC, charcoal) urinary alkalinization with intravenous sodium bicarbonate - enhances elimination of aspirin in the urine haemodialysis Indications for haemodialysis in salicylate overdose serum concentration > 700mg/L metabolic acidosis resistant to treatment acute renal failure pulmonary oedema seizures coma

Question 50

Side effects pages

Answer 50

look at these

Question 51

Tamoxifen SE's

Answer 51

menstrual disturbance: vaginal bleeding, amenorrhoea hot flushes - 3% of patients stop taking tamoxifen due to climacteric side-effects venous thromboembolism endometrial cancer Raloxefine lowers endometrial cancer risk

Question 52

Teratogens page

Answer 52

look at this

Question 53

Theopylline toxicity

Answer 53

Regardless of the time of presentation give activated charcoal to reduce absorption Definitive treatment is with haemodialysis

Question 54

Prescribing in people with asthma and COPD

Answer 54

A number of drugs should be used with caution in patients with asthma: NSAIDs beta-blockers adenosine (usde verapamil instead)

Question 55

Timing of prescription

Answer 55

The following medications are usually taken at night: statins amitriptyline

Question 56

Frequency of prescriptions

Answer 56

The following medications are usually prescribed weekly in the UK: bisphosphonates methotrexate

Question 57

Drugs and potassium

Answer 57

Decrease K Thiazide diuretics Loop diuretics Acetazolamide Increase K ACE inhibitors Angiotensin-2 receptor blockers Spironolactone Potassium sparing diuretics (amiloride, triamterene) Potassium supplements (Sando-K, Slow-K)

Question 58

Peripheral neuropathy

Answer 58

amiodarone isoniazid vincristine nitrofurantoin metronidazole

Question 59

Ivabradine

Answer 59

Adverse effects visual effects, particular luminous phenomena, are common headache bradycardia, heart block

Question 60

Loop diuretics (furosemide and bumetanide)

Answer 60

Adverse effects hypotension hyponatraemia hypokalaemia, hypomagnesaemia hypochloraemic alkalosis ototoxicity hypocalcaemia renal impairment (from dehydration + direct toxic effect) hyperglycaemia (less common than with thiazides) gout

Question 61

Methotrexate

Answer 61

Adverse effects mucositis myelosuppression pneumonitis pulmonary fibrosis liver fibrosis Interactions avoid prescribing trimethoprim or co-trimoxazole concurrently - increases risk of marrow aplasia high-dose aspirin increases the risk of methotrexate toxicity secondary to reduced excretion Methotrexate toxicity the treatment of choice is folinic acid

Question 62

Nicorandil

Answer 62

Adverse effects headache flushing skin, mucosal and eye ulceration gastrointestinal ulcers including anal ulceration Contraindications left ventricular failure

Question 63

Nitrates

Answer 63

Side-effects hypotension tachycardia headaches flushing Nitrate tolerance many patients who take nitrates develop tolerance and experience reduced efficacy the BNF advises that patients who develop tolerance should take the second dose of isosorbide mononitrate after 8 hours, rather than after 12 hours. This allows blood-nitrate levels to fall for 4 hours and maintains effectiveness this effect is not seen in patients who take modified release isosorbide mononitrate

Question 64

Phenytoin adverse effects

Answer 64

Acute initially: dizziness, diplopia, nystagmus, slurred speech, ataxia later: confusion, seizures Chronic common: gingival hyperplasia (secondary to increased expression of platelet derived growth factor, PDGF), hirsutism, coarsening of facial features, drowsiness megaloblastic anaemia (secondary to altered folate metabolism) peripheral neuropathy enhanced vitamin D metabolism causing osteomalacia lymphadenopathy dyskinesia Idiosyncratic fever rashes, including severe reactions such as toxic epidermal necrolysis hepatitis Dupuytren's contracture* aplastic anaemia drug-induced lupus Teratogenic associated with cleft palate and congenital heart disease

Question 65

Valproate

Answer 65

Adverse effects teratogenic P450 inhibitor gastrointestinal: nausea increased appetite and weight gain alopecia: regrowth may be curly ataxia tremor hepatotoxicity pancreatitis thrombocytopaenia hyponatraemia hyperammonemic encephalopathy:

Question 66

Sulfonylureas

Answer 66

Common adverse effects hypoglycaemic episodes (more common with long-acting preparations such as chlorpropamide) weight gain Rarer adverse effects hyponatraemia secondary to syndrome of inappropriate ADH secretion bone marrow suppression hepatotoxicity (typically cholestatic) peripheral neuropathy Sulfonylureas should be avoided in breastfeeding and pregnancy.

Question 67

Thiazide diuretics (bendroflumethiazide)

Answer 67

Common adverse effects dehydration postural hypotension hyponatraemia, hypokalaemia, hypercalcaemia* gout impaired glucose tolerance impotence Rare adverse effects thrombocytopaenia agranulocytosis photosensitivity rash pancreatitis

Question 68

Triptans

Answer 68

Contraindications patients with a history of, or significant risk factors for, ischaemic heart disease or cerebrovascular disease

Question 69

General factors that may potentiate warfarin

Answer 69

liver disease P450 enzyme inhibitors (see below) cranberry juice drugs which displace warfarin from plasma albumin, e.g. NSAIDs inhibit platelet function: NSAIDs

Question 70

5-HT3 antagonists

Answer 70

5-HT3 antagonists are antiemetics used mainly in the management of chemotherapy-related nausea. They mainly act in the chemoreceptor trigger zone area of the medulla oblongata. Examples ondansetron palonosetron second-generation 5-HT3 antagonist main advantage is reduced effect on the QT interval Adverse effects prolonged QT interval constipation is common

Question 71

ACE-I

Answer 71

Side-effects: cough occurs in around 15% of patients and may occur up to a year after starting treatment thought to be due to increased bradykinin levels angioedema: may occur up to a year after starting treatment hyperkalaemia first-dose hypotension: more common in patients taking diuretics Cautions and contraindications pregnancy and breastfeeding - avoid renovascular disease - may result in renal impairment aortic stenosis - may result in hypotension hereditary of idiopathic angioedema specialist advice should be sought before starting ACE inhibitors in patients with a potassium >= 5.0 mmol/L

Question 72

Suxamethanium and the eye

Answer 72

contraindicated for patients with penetrating eye injuries or acute narrow angle glaucoma, as suxamethonium increases intra-ocular pressure

Question 73

Drug Monitoring

Answer 73

See passmed page

Question 74

Malignant hyperthermia

Answer 74

Malignant hyperthermia (MH) is a rare, serious side effect of volatile liquid anaesthetics (isoflurane, desflurane, sevoflurane), which cause all skeletal muscle to rapidly contract, including during a neuromuscular blockade. MH is a genetic disorder, manifesting due to calcium overload in the skeletal muscle causing sustained muscular contraction and rhabdomyolysis, resulting in excess anaerobic metabolism causing acidosis. End-tidal CO2 increases as a result, along with body temperature which causes diaphoresis (excess sweating).

Question 75

Cardiac arrest due to opioid toxicity

Answer 75

400 microgram bolus of naloxone

Question 76

Etomidate

Answer 76

Adrenal suppression

Question 77

Suxamethonium

Answer 77

Good for rapid induction of anaesthesia Can cause irreversible muscle twitching

Question 78

Opioids in renal failure

Answer 78

Oxycodone if renal impairment is more severe, alfentanil, buprenorphine and fentanyl are preferred

Question 79

Antiemetics for certain situations

Answer 79

Raised ICP- cyclizine Chemo-induced- ondansetron, haloperidol and levomepromazine Reduced gastric motility- metoclopramide (not in obstruction however) Vestibular- cyclizine PD- domperidone

Question 80

Drugs that can cause urinary retention

Answer 80

Opioids, tricyclic antidepressants, anticholinergics, and NSAIDs.

Question 81

Domperidone

Answer 81

domperidone, another dopamine antagonist licensed for the treatment of nausea, is safe to use for patients with Parkinson’s disease as it does not cross the blood-brain barrier).

Question 82

Combination antiplatelet and anticoagulant therapy

Answer 82

Secondary prevention of stable cardiovascular disease with an indication for an anticoagulant normally in this situation, all patients are recommended to be prescribed an antiplatelet if an indication for anticoagulant exists (for example atrial fibrillation) it is indicated that anticoagulant monotherapy is given without the addition of antiplatelets Post-acute coronary syndrome/percutaneous coronary intervention in these patients, there is a much stronger indication for antiplatelet therapy generally patients are given triple therapy (2 antiplatelets + 1 anticoagulant) for 4 weeks-6 months after the event and dual therapy (1 antiplatelet + 1 anticoagulant) to complete 12 months

Question 83

Vitamin D and bisphosphonates

Answer 83

vitamin D and calcium have to be corrected first before giving bisphosphanates

Question 84

Hyoscine

Answer 84

respiratory secretions & bowel colic may be treated by hyoscine hydrobromide, hyoscine butylbromide, or glycopyrronium bromide

Question 85

Hydrocortisone supplementation

Answer 85

Hydrocortisone supplementation is required prior to surgery for patients taking prednisolone

Question 86

Carbon monoxide poisoning

Answer 86

Smokers may normally have carboxyhaemoglobin levels of up to 10%

Question 87

methaemaglobin

Answer 87

Nitrates, including recreational nitrates such as amyl nitrite ('poppers') may cause methaemoglobinaemia

Question 88

ciclosporin SE's

Answer 88

everything is increased - fluid, BP, K+, hair, gums, glucose

Question 89

General rules diabetes and surgery

Answer 89

patients treated with insulin who have good glycaemic control (HbA1c < 69 mmol/mol) and are undergoing minor procedures, can be managed during the operative period by adjustment of their usual insulin regimen (surgery requiring a long fasting period of more than one missed meal) or whose diabetes is poorly controlled, will usually require a variable rate intravenous insulin infusion (VRIII)

Question 90

Metformin and surgery

Answer 90

If taken once or twice a day - take as normal If taken three times per day, omit lunchtime dose

Question 91

Sulfonylureas

Answer 91

If taken once daily in the morning - omit the dose that day If taken twice daily - omit the morning dose that day If afternoon operation- omit both doses

Question 92

DPP4-I and surgery

Answer 92

Take as normal

Question 93

GLP-1 analogues

Answer 93

Take as normal

Question 94

SGLT-2 inhibitors

Answer 94

Omit on the day of surgery

Question 95

SGLT-2 inhibitors

Answer 95

Omit on the day of surgery

Question 96

Once daily insulins eg. lantus and levemir

Answer 96

Reduce dose by 20%

Question 97

Twice daily insulins eg. novomix and humulin

Answer 97

Halve the usual morning dose. Leave evening dose unchanged

Question 98

amiloride

Answer 98

potassium sparring diuretic

Question 99

Cytotoxic agents main SE's

Answer 99

cyclophosphamide- bladder doxorubicin- cardiomyopathy methotrexate/5-fu- mucositis vincristine/cisplatin- peripheral neuropathy cisplatin- ototoxic, hypomagnesia

Question 100

sedating antihistamine

Answer 100

Chlorphenamine Cyproheptadine Hydroxyzine Promethazine

Question 101

non sedating antihistamines

Answer 101

Cetirizine Fexofenadine Loratadine

Question 102

Booster pneumococcal vaccine

Answer 102

Every 5 years to people with spleen issues/CKD NB- given once only to others eg. cardioresp disease: COPD/asthma/CHF (no booster)

Question 103

Pain relief in severe renal disease

Answer 103

eGFR <10- fentanyl or buprenophine eGFR 10-50- oxycodone