Top 100 drugs Flashcards
What are the common indications for N-acetylcysteine?
An antidote for paracetamol poisoning
To help prevent renal injury due to radiographic contract material (contrast nephropathy)
To reduce the viscosity of respiratory secretions
What are the mechanisms of action of N-acetylcysteine?
Replenishing the body’s supply of glutathione
What are the important adverse effects of N-acetylcysteine?
Anaphylactic reaction
Bronchospasm
What are the common indications for adenosine?
Supraventricular tachycardia
What are the mechanisms of action of adenosine?
Increases AVN refractoriness, which breaks the circuit
What are the important adverse effects of adenosine?
Bradycardia Asystole Sinking feeling in the chest Breathlessness Sense of impending doom
What are the contraindications of adenosine?
Hypotension Coronary ischaemia Decompensated heart failure Asthma COPD Heart transplant
How is activated charcoal administered?
Usually mixed with 250mL of water to form a suspension, which the patient then drinks, if the patient is unconscious
How is adenosine administered?
Through a large bore cannula by an experienced physician. Initially 6mg over 2 seconds
What are the common indications for adrenaline?
Cardiac arrest
Anaphylaxis
Induce local vasoconstriction (e.g. mucosal bleeding)
What is the mechanism of action of adrenaline?
Potent agonist of the alpha and beta adrenoceptors
What are the important adverse effects of adrenaline?
Adrenaline-induced hypertension Anxiety Tremor Headache Palpitations Angina MI Arrhythmia
How is adrenaline administered?
Cardiac arrest: 10mL: 1mg in 10mL (1:10,000) pre-filled syringe
Anaphylaxis: 0.5mL: 1mg in 1mL (1:1000) IM injection into the anterolateral aspect of the thigh
What are the common aldosterone antagonists?
Spironolactone and elperonone
What are the common indications of aldosterone antagonists? (spironolactone and elperonone)
Ascites and oedema due to liver cirrhosis
Chronic heart failure (not first line)
Primary hyperaldosteronism
What is the mechanism of action of aldosterone antagonists?
They competitively bind to the aldosterone receptor
What are the important adverse effects of aldosterone antagonists?
Severe renal impairment
Hyperkalaemia
Addison’s disease
Pregnant or lactating women
What are some important interactions of aldosterone antagonists?
Other potassium elevating drugs such a ACE inhibitors and angiotensin receptor blockers.
How are aldosterone antagonists administered?
Spironolactone generally with food: 100-400mg daily
What are the common alginates and antacids?
Gaviscon
Peptac
What are the common indications for alginates and antacids?
GORD
Dyspepsia
What are the mechanism of actions of alginates and antacids?
Buffering stomach acids
Increase the viscosity of the stomach contents
What are the important adverse effects of alginates and antacids?
Diarrhoea
Constipation
What are the important interactions of alginates and antacids?
Reduces the concentration (so should be taken at different times) of ACE inhibitors, cephalosporins, bisphosphonates, digoxin, levothyroxine and PPIs.
How are alginates and antacids administered?
Following meals, before bedtime and/or when symptoms occur
What are the common indications of allopurinol?
Prevent acute attacks of gout
Prevent uric acid and calcium oxalate renal stones
Prevent hyperuricaemia and tumour lysis syndrome (associated with chemotherapy)
What is the mechanism of action of allopurinol?
Xanthine oxidase inhibitor
What are the important adverse effects of allopurinol?
A skin rash
Stevens-johnson syndrome
Toxic epidermal necrosis
Can trigger or worsen an acute attack of gout
What are the contraindications of allopurinol?
Acute attacks of gout
Recurrent skin rash
Dose should be reduced in renal or hepatic impairment
How is allopurinol administered?
Taken after meals and should be encouraged to maintain good hydration with fluid intake of 2-3 litres daily.
What are some common alpha blockers?
Doxazosin
Tamsulosin
Alfuzosin
What are the common indications for alpha blockers?
Benign prostatic hyperplasia
Resistant hypertension
What is the mechanism of action of alpha blockers?
Block alpha adrenoreceptor (usually alpha 1).
Vasodilation - reduced resistance to bladder outflow
What are the important adverse effects of alpha blockers?
Postural hypotension
Dizziness
Syncope
What are the contraindications of alpha blockers?
Postural hypotension
How are alpha blockers administered?
2-4mg daily
What are some common aminoglycosides?
Gentamicin
Amikacin
What are some common indications of aminoglycosides?
Severe sepsis
Pyelonephritis
Biliary (intra-abdominal) sepsis
Endocarditis
What is the mechanism of action of aminoglycosides?
Bind irreversibly to bacterial ribosomes and inhibit protein synthesis
What are the important adverse effects of aminoglycosides?
Nephrotoxicity
Ototoxicity
What are the important contraindications to aminoglycosides?
Neonates & elderly
Renal impairment
Myasthenia gravis
How are aminoglycosides administered?
Sepsis: 3-5mg/kg daily in 3 divided doses (IV injection)
Endocarditis: 1 mg/kg every 12 ours IV injection
What are some common aminosalicylates?
Mesalazine
Sulfasalazine
What are the common indications of aminosalicylates?
Ulcerative colitis
Rheumatoid arthritis
What is the mechanism of action of aminosalicylates?
They release 5-aminosalicylic acid, which has both anti-inflammatory and immunosuppressive effects
What are the important adverse effects of aminosalicylates?
GI upset and headache
Leucopaenia, thrombocytopaenia and renal imparirment
What are the contraindications of aminosalicylates?
Aspirin hypersensitivity
How are aminosalicylates administered?
Foam enemas or tablets
What are the common indications of amiodarone?
Tachyarrythmias such as AF and SVT
What is the mechanism of action of amiodarone?
Blocks sodium, potassium and calcium channels and antagonism of alpha and beta adrenergic receptors in the myocardial cells
What are the important adverse effects of amiodarone?
Acute: hypotension
Chronic: pneumonitis, bradycardia, AV block, hepatitis, photosensitivity
What conditions should amiodarone not be used in?
Severe hypotension
Heart block
Active thyroid disease
What are the important drug interactions of amiodarone?
Digoxin, diltiazem and verapamil should all be halved when taking amiodarone
What are some common ACE-inhibitors?
Ramipril, lisinopril, perindopril
What are the common indications of ACE inhibitors?
Hypertension
Chronic heart failure
Ischaemic heart disease
Diabetic nephropathy and CKD
What are the mechanisms of ACE inhibitors?
Blocks the action of ACE, which prevents the conversion of angiotensin I to angiotensin II
What are the important adverse effects of ACE inhibitors?
Hypotension Persistent dry cough Hyperkalaemia Renal failure Angioedema
In what conditions should ACE inhibitors not be used in?
Renal artery stenosis AKI Pregnancy Breastfeeding CKD
What are some important interactions of ACE inhibitors?
Potassium elevating drugs (potassium-sparing diuretics)
NSAIDs
What are some common angiotensin receptor blockers?
Losartan, candesartan, irbesartan
What are the common indications of angiotensin receptor blockers?
HTN
Chronic heart failure
Ischaemic heart disease
Diabetic nephropathy and CKD
What is the mechanism of action of angiotensin receptor blockers?
They block the action of angiotensin II on the AT receptor
What are the important adverse effects of angiotensin receptor blockers?
Hypotension
Hyperkalaemia
Renal failure
In what conditions are angiotensin receptor blockers not to be used?
Renal artery stenosis
AKI
Pregnancy/breastfeeding
CKD
What are the important interactions with angiotensin receptor blockers?
Potassium elevating drugs
What are some common SSRIs?
Citalopram
Fluoxetine
Sertraline
Escitalopram
What are some common indications of SSRIs?
Moderate to severe depression
Panic disorder
OCD
What is the mechanism of action of SSRIs?
Inhibit neuronal reuptake of serotonin
What are some important adverse effects of SSRIs?
GI upset, appetite and weight disturbance. Hypersensitivity Hyponatraemia Suicidal thoughts and behaviour Lower the seizure threshold Prolong the QT interval Risk of bleeding Serotonin syndrome
In what conditions should SSRIs not be used?
Epilepsy
Peptic ulcer disease
Hepatic impairment
What are the important drug interactions with SSRIs?
MOA inhibitors
Antipsychotics (drugs that also prolong the QT interval)
What are some common tricyclic antidepressants?
Amitriptyline
Lofepramine
What are some common indications for tricyclic antidepressants?
Moderate to severe depression
Neuropathic pain
What is the mechanism of action of tricyclic antidepressants?
Inhibit neuronal reuptake of serotonin and noradrenaline (also lots of other receptors)
What are the important adverse effects of tricyclic antidepressants?
Antimuscarinic side effects (dry mouth, constipation, urinary retention and blurred vision).
Sedation and hypotension
Arrhythmias and ECG changes
Convulsions, hallucinations and mania
Breast changes, sexual dysfunction.
Extrapyramidal side effects (tremor & dyskinesia)
Dangerous in overdose.
In what conditions should tricyclic antidepressants not be used?
Elderly CVD Epilepsy Constipation Prostatic hypertrophy Raised intraocular pressure
What are some important drug interactions with tricyclic antidepressants?
MOA inhibitors
What are some D2-receptor antagonists?
Metoclopramide
Domperidone
What are the common indications for using D2-receptor antagonists?
Nausea and vomiting, particularly in reduced gut motility
What is the mechanism of action of D2-receptor antagonists?
The D2 receptor is the main receptor in the chemoreceptor trigger zone, it promotes relaxation of the stomach and lower oesophageal sphincter. D2 receptors therefore have a pro kinetic effect and promote stomach emptying
What are the important adverse effects of D2 receptor antagonists?
Diarrhoea
Extrapyramidal syndromes
Acute dystonic reaction
In what conditions should D2-receptor antagonists not be used as anti-emetics?
Young adults and children
Gi obstruction
Performation
What are the some important drug interactions with D2-receptor antagonists?
Antipsychotics
Dopaminergic agents for Parkinson’s disease
What are some common H1-receptor antagonists (antiemetics)?
Cyclizine
Cinnarizine
Promethazine
What are the common indications of H1-receptor antagonists (antiemetics)?
Nausea & Vomiting
Motion sickness
Vertigo
What are the mechanisms of H1-receptor antagonists (antiemetics)?
Blocks both histamine and acetylcholine (muscarinic) receptors in the vomiting centre.
What are the important adverse effects of H1-receptor antagonists (antiemetics)?
Drowsiness
Dry throat and mouth
Tachycardia
Palpitations
What are the contraindications associated with H1-receptor antagonists (antiemetics)?
Sedation
Hepatic encephalopathy
Prostatic hypertrophy
What are the important interactions with H1-receptor antagonists (antiemetics)?
Greater sedation associated with benzodiazepines or opioids.
Anticholinergic effects may be more pronounced in patients taking ipratropium or tiotropium.
What are some common phenothiazines antiemetics?
Prochlorperazine and chlorpromazine
What are the common indications of phenothiazines antiemetics?
Nausea and vomiting, particularly due to vertigo.
Psychotic disorders, such as schizophrenia, where they are used as first-generation (typical) antipsychotics.
What is the mechanism of phenothiazine antiemetics?
Block lots of receptors, including dopamine, histamine, and acetylcholine.
What are the important adverse effects of phenothiazine antiemetics?
Drowsiness Postural hypotension Extrapyramidal syndromes Acute dystonic reaction Tardive dyskinesia Long QT interval
What are the contraindications of phenothiazine antiemetics?
Severe liver disease
Prostatic hypertrophy
Doses should be reduced in the elderly
What are the common examples of serotonin 5-HT3-receptor antagonists?
Ondansetron
Granisetron
What are the common indications of serotonin 5-HT3- receptor antagonists?
Nausea and vomiting, particularly in general anaesthesia and chemotherapy
What is the mechanism of serotonin 5-HT3-receptor antagonists?
It inhibits the serotonin 5-HT3-receptor in the gut, which means it is effective against sickness due to gut causes, but not in motion sickness.
What are the important adverse effects of serotonin 5-HT3-receptor antagonists?
Very rare!
Constipation
Diarrhoea
Headaches
What are the contraindications of serotonin 5-HT3-receptor antagonists?
Prolonged QT intervals
What are the important interactions of serotonin 5-HT3-receptor antagonists?
Avoid drugs that prolong the QT interval
What are some common antifungal drugs?
Nystatin
Clotrimazole
Fluconazole
What are some common indications for antifungal drugs?
Local fungal infections (oropharynx, vagina or skin).
May be applied topically (nystatin, clotrimazole) or taken orally (fluconazole)
What is the mechanism of action of antifungal drugs?
They can kill or slow the growth of the fungi
What are the important adverse effects of antifungals?
Local irritation where applied.
Fluconazole: GI upset, headache, hepatitis
What are the contraindications to fluconazole?
Liver disease
Moderate renal impairment
Pregnancy
What are the important interactions of antifungals?
Drugs that are metabolised by P450 enzymes (phenytoin, carbamepine, warfarin, diazepam, simvastatin, sulphonylureas)
Drugs that prolong the QT interval (amiodarone, antipsychotics, quinine, quinolone, macrolide antibiotics, SSRIs)
What are some examples of H1-receptor antagonists (antihistamines)?
Cetirizine, loratadine, fexofenadine, chlorphenamine
What are the common indications of H1-receptor antagonists (antihistamines)?
Allergies, particularly hay fever
Aid relief of itchiness and hives (pruritus, and urticaria)
What is the mechanism of action of H1-receptor antagonists (antihistamines)?
The block the histamine receptors.
What are the important adverse effects of H1-receptor antagonists (antihistamines)?
Sedation
What are the contraindications of H1-receptor antagonists (antihistamines)?
Severe liver disease
What are some common antimotility drugs?
Loperamide
Codeine phosphate
What are the common indications for antimotility drugs?
Symptomatic treatment for diarrhoea
What is the mechanism of action of antimotility drugs?
Agonist of the opioid receptors in the GI tract so transit of bowel contents is slowed and anal sphincter tone is increased
What are the important adverse effects of antimotility drugs?
GI effects such as constipation, abdominal cramping and flatulence
What are the contraindications to antimotility drugs?
Acute ulcerative colitis
C.diff colitis
Acute bloody diarrhoea
What are some common antimuscarinic bronchodilators?
Ipratropium
Tiotropium
Glycopyrronium
What is the mechanism of action of antimuscarinic bronchodilators?
They competitively inhibit acetylcholine, which reduced smooth muscle tone and reduces secretions
What are the important adverse effects of antimuscarinic bronchodilators?
very little, just a little dry mouth
What are some contraindications of antimuscarinics?
Patients susceptible to angle-closure glaucoma
What are some common antimuscarinics used in cardio?
Atropine
What are some common antimuscarinics used in GI?
Hyoscine butylbromide
What are some common antimuscarinics used in resp?
Glycopyrronium
What are the common indications of atropine?
Bradycardia
What are the common indications for hyoscine butylbromide?
IBS
What are the common indications for Glyopyrronium?
Copious respiratory secretions in palliative care
What is the common mechanism of action of antimuscarinics?
Competitive inhibitor of acetylcholine.
They increase heart rate and conduction; reduce smooth muscle tone and peristaltic contraction and reduce gland secretion.
What are some important adverse effects to antimuscarinic drugs?
Tachycardia Dry mouth Constipation Urinary retention Blurred vision Drowsiness Confusion
What are some important interactions to antimuscarinic drugs?
Adverse effects are more pronounced when they are combined with other drugs that have antimuscarinic effects, such as tricyclic antidepressants
What are some common antimuscarinics used in the genitourinary system?
Oxybutanin
Tolterodine
Solifenacin
What are the common indications of antimuscarinics used in the genitourinary system?
To reduce urinary frequency, urgency and urge incontinence in overactive bladder
What are some typical antipsychotics?
Haloperidol
Chlorpromazine
Prochlorperazine
What are some common indications of typical antipsychotics?
[1] Urgent treatment of severe psychomotor agitation
[2] Schizophrenia
[3] Bipolar disorder, particularly in acute episodes of mania or hypomania
[4] Nausea and vomiting, particularly in palliative care setting
What is the mechanism of action of typical antipsychotics?
They block post-synaptic dopamine D2 receptors
What are the important adverse effects of typical antipsychotics?
Extrapyramidal effects (acute dystonic reaction, akathisia, neuroleptic malignant syndrome and tardive dyskinesia) Drowsiness, hypotension, QT interval prolongation, erectile dysfunction, hyperprolactinaemia
What are the contraindications of typical antipsychotics?
Elderly
Dementia
Parkinsons disease
What are the important interactions of typical antipsychotics?
Drugs that prolong QT interval (amiodarone, macrolides)
What are some atypical antipsychotics?
Quetiapine
Olanzapine
Risperidone
Clozapine
What are some common indications of atypical antipsychotics?
Urgent treatment of severe psychomotor agitation
Schizophrenia (in prominent negative symptom present or if typical antipsychotics haven’t worked)
Bipolar disorder (particularly in acute episodes of mania or hypomania
What is the mechanism of action of atypical antipsychotics?
Block post-synaptic dopamine D2 receptors.
What are the important adverse effects of atypical antipsychotics?
Sedation
Extrapyramidal effects.
Can cause breast symptoms and sexual dysfunction
What are the contraindications of atypical antipsychotics?
CVD
Severe heart disease
Clozapine: NEUTROPAENIA
What are some important drug interactions of atypical antipsychotics?
Should not be combined with other dopamine-blocking antiemetics
Drugs that prolong the QT interval (amiodarone
, quinine, macrolides, SSRIs)
What are the common indications of aspirin?
[1] Acute coronary syndrome and acute ischaemic stroke
[2] Long term secondary prevention of thrombotic arterial events in cardiovascular, cerebrovascular and peripheral arterial disease
[3] Reduce risk of stroke in AF
[4] Control mild-to-moderate pain and fever
What is the mechanism of action of aspirin?
Irreversibly inhibits cyclooxygenase
Reducing platelet aggregation
What are the important adverse effects of aspirin?
GI irritation, possibly ulceration and bleeding
Bronchospasm
Tinnitus if used long term high dose
What are the contraindications to aspirin?
Not used in children (due to Reye's syndrome) Aspirin hypersensitivity Not in third trimester Peptic ulceration Gout
What are some important interactions for aspirin?
Antiplatelets (clopidogrel, dipyridamole)
Anticoagulants (heparin, warfarin)
What are some common benzodiazepines?
Diazepam Temazepam Lorazepam Chlordiazepoxide Midazolam
What are some common indications benzodiazepines?
[1] Seizure and status epilepticus
[2] Alcohol withdrawal reactions
[3] Sedation for interventional procedures
[4] Short-term treatment of severe, disabling or distressing anxiety
[5] Short-term treatment of severe, disabling or distressing insomnia
What is the common mechanism of action of benzodiazepines?
Facilitate and enhance binding of GABA to the GABA receptors
What are the important adverse effects of benzodiazepines?
Drowsiness, sedation and coma
Dependence
What are the contraindications of benzodiazepines?
Elderly
Respiratory impairment or neuromuscular disease (myasthenia gravis)
Liver failure
What are the important interactions of benzodiazepines?
Most depend on cytochrome P450 enzymes for elimination, so con-current use with cytochrome P450 inhibitors may increase their effect (amiodarone, diltiazem, macrolides, fluconazole)
What are some common beta2-agonists?
Salbutamol
Salmeterol
Formoterol
Terbutaline
What are some common indications of beta2-agonists?
Asthma
COPD
Hyperkalaemia
What is the mechanism of action of beta2-agonists?
Smooth muscle relaxation
Stimulate Na/K-ATPase pumps on cell surface, causing a shift of K from the extracellular to intracellular compartment.
What are the important adverse effects of beta2-agonists?
Tachycardia, palpitations, anxiety and tremor
What are the contraindications of beta2-agonists?
CVD in patients in whom tachycardia may provoke angina or arrhythmias
What are the important interactions of beta2-agonists?
Beta blockers may reduce the effectiveness of beta2-agonists.
If used with corticosteroids
What are some common beta blockers?
Bisoprolol
Atenolol
Propranolol
What are some common indications to beta blockers?
Ischaemic heart disease Chronic heart failure AF SVT HTN
What is the mechanism of beta blockers?
Reduce the force of contraction and speed of conduction in the heart.
Prolong the refractory period of the AV node.
Reduce renin secretion from the kidney
What are the important adverse effects of beta blockers?
Fatigue, cold extremities, headache, GI disturbance, sleep disturbance and nightmares, may cause impotence in men.
What are the contraindications of beta blockers?
Asthma
Haemodynamic instability
Heart block
What are some important drug interactions of beta blockers?
Do not use in non-dihydropyridine calcium channel blockers (verapamil, diltiazem)
What are some common bisphosphonates?
Alendronic acid
Zoledronic acid
What are some common indications for bisphosphonates?
Risk of osteoporotic fragility fractures
Severe hypercalcaemia of malignancy
Myeloma and breast cancer with bone metastases
Paget’s disease
What is the mechanism of action of bisphosphonates?
Reduce bone turnover by inhibiting the action of osteoclasts and promote apoptosis. Net effect is reduction in bone loss and improvement of bone mass.
What are the important adverse effects of bisphosphonates?
Oesophagitis
Hypophosphataemia
Rare but serious: osteonecrosis of the jaw
What are the contraindications of bisphosphonates?
Severe renal impairment
Hypocalcaemia
Oral administration is contraindication in patients with upper GI disorders.
Be careful in smokers and major dental disease
What are the important drug interactions of bisphosphonates?
Bisphosphonates absorption is reduced if taken with calcium salts as well as antacids and iron salts
What are some common calcium and vitamin D drugs?
Calcium carbonate
Calcium gluconate
Colecalciferol
Alfacalcidol
What are some common indications of calcium and vitamin D drugs?
Osteoporosis CKD Severe hyperkalaemia Hypocalcaemia Vitamin D deficiency
What are the important adverse effects of calcium and vitamin D drugs?
Dyspepsia and constipation
Cardiovascular collapse if IV administered too fast
Local tissue damage if accidentally given into SC tissue
What are some contraindications of calcium and vitamin D drugs?
Hypercalcaemia
What are some important drug interactions of calcium and vitamin D drugs?
Reduces the absorption of iron, bisphosphonates, tetracyclinesnad levothyroxine
Administered IV, calcium must not be allowed to mix with sodium bicarbonate
What are some calcium channel blockers?
Amlodipine
Nifedipine
Diltiazem
Verapamil
What are some common indications for calcium channel blockers?
HTN
Stable angina
Supraventricular arrythmias
What is the mechanism of action of calcium channel blockers?
Decrease calcium entry into vascular and cardiac cells, reducing intracellular calcium concentration. This causes relaxation and vasodilation in arterial smooth muscle.
Reduce myocardial contractility. Suppress cardiac conduction.
What are the important adverse effects of calcium channel blockers?
Ankle swelling, flushing, headache, palpitations and constipation.
Less often but more serious: bradycardia, heart block and cardiac failure
What are some contraindications of calcium channel blockers?
Verapamil and diltiazem used in caution in patients with poor left ventricular function.
Generally avoided in AV nodal conduction delay.
Amlodipine and nifedipine avoided in unstable angina and severe aortic stenosis
What are some important drug interactions of calcium channel blockers?
Non-dihydropyridine calcium channel blockers (verapamil and diltiazem) should not be prescribed with beta blockers.
What are the common indications of carbamazepine?
Epilepsy
Trigeminal neuralgia
Bipolar disorder
What is the mechanism of action of carbamazepine?
Incompletely understood, appears to inhibit neuronal sodium channels, stabilising resting membrane potentials and reduce neuronal excitability.
What are the important adverse effects of carbamazepine?
GI upset Neuro effects (dizziness and ataxia) Hypersensitivity Anti-epileptic hypersensitivity syndrome (severe skin reactions, fever and lymphadenopathy and systemic involvement) Oedema and hyponatraemia
What are the contraindications of carbamazepine?
Pregnancy
Prior anti epileptic hypersensitivity syndrome
Use caution in hepatic, renal or cardiac disease
What are the important drug interactions of carbamazepine?
Reduces efficacy of drugs that are metabolised by P450 enzymes (warfarin, oestrogen and progestogens).
Carbamazepine concentration increased by cytochrome P450 inhibitors (macrolides).
The efficacy of anti epileptic drugs is reduced by drugs that lower the seizure threshold (SSRIs, tricyclic antidepressants, antipsychotics, tramadol)
What are some cephalosporins and carbapenems?
Cefalexin
Cefotaxime
Meropenem
Ertopenem
What are some common indications for cephalosporins and carbapenems?
2nd and 3rd line treatment for urinary and respiratory tract infections
IV drugs used to treat very severe or complicated or cause by antibiotic-resistant organisms
What is the mechanism of action of cephalosporins and carbapenems?
Antimicrobial effect due to beta lactic ring, weakens bacterial cell walls, resulting in bacterial cell swelling, lysis and death.
What are the important adverse effects of cephalosporins and carbapenems?
GI upset common. Antibiotic-associated colitis less common.
Hypersensitivity
Risk of central nervous system toxicity including seizures.
What are some contraindications to cephalosporins and carbapenems?
Used with caution in people at risk of C.diff, particularly those in hospital and the elderly.
History of allergy to penicillin, cephalosporin or carbapenems.
Carbapenems used with caution in those with epilepsy
What are the important drug interactions with cephalosporin and carbapenems?
They can enhance the anticoagulant effect of warfarin.
Increase nephrotoxicity of aminoglycosides.
Carbapenems reduce plasma concentration and efficacy of valproate
What are the common indications of clopidogrel?
Acute coronary syndrome
Prevent occlusion of coronary artery stenosis
Long term secondary prevention of thrombotic arterial events in patients with CV, cerebrovascular and peripheral arterial disease
Reduce thrombotic risk in AF
What is the mechanism of action of clopidogrel?
Prevents platelet aggregation and reduces the risk of arterial occlusion by binding irreversibly to ADP receptors (P2Y12) on the surface of platelets
What are the important adverse effects of clopidogrel?
Important: bleeding
Common: GI upset, including dyspepsia, abdominal pain and diarrhoea
Thrombocytopaenia
What are the contraindications of clopidogrel?
Significant active bleeding
Stop 7 days before elective surgery
Use with caution in renal and hepatic impairment
What are the important drug interactions of clopidogrel?
Clopidogrel efficacy reduced by cytochrome P450 inhibitors (omeprazole, ciprofloxacin, erythromycin, antifungals and SSRIs).
Co-prescription of clopidogrel with other anti platelet drugs (aspirin), anticoagulants (heparin) or NSAIDs increase the risk of bleeding
What are some common beta2 agonist corticosteroid inhalers?
Seretide
Symbicort
What are some common indications of beta2 agonist corticosteroid inhalers?
Asthma (used in step 3-4)
COPD (controls symptoms)
What is the mechanism of action of beta2 agonist corticosteroid inhalers?
Corticosteroid suppresses airway inflammation and long acting beta2 agonist stimulates bronchodilation
What are the important adverse effects of beta2 agonist corticosteroid inhalers?
Oral thrush, hoarse voice.
Increase risk of pneumonia in people with COPD.
Tremor, tachycardia, arrhythmias and muscle cramps
What are the contraindications of beta2 agonist corticosteroid inhalers?
Used in caution with COPD patients with a history of pneumonia and children and patients with cardiovascular disease
What are the important drug interactions of beta2 agonist corticosteroid inhalers?
Beta blockers may reduce the effectiveness of the inhaler
What are some common systemic glucocorticoids?
Prednisolone
Hydrocortisone
Dexamethosone
What are some common indications for systemic glucocorticoids?
To treat allergic or inflammatory disorders
Suppress autoimmune disease
In the treatment of some cancers as part of chemotherapy or to reduce tumour associated swelling.
Hormone replacement in adrenal insufficiency or hypopituitarism
What is the mechanism of action of systemic glucocorticoids?
Immunosuppression: Modify the immune response, upregulate anti-inflammatory genes and down regulate pro-inflammatory genes.
Metabolic effects: increased gluconeogenesis, increased catabolism
Mineralocorticoid effects: stimulate Na and water retention and K excretion in the renal tubule
What are the important adverse effects of systemic glucocorticoids?
Immunosuppression Metabolic: diabetes mellitus and osteoporosis, increased catabolism causes proximal muscle weakness, skin thinning with easy bruising and gastritis. Mood and behavioural changes. HTN, hypokalaemia and oedema Adrenal atrophy
What are the contraindications of systemic glucocorticoids?
Use in caution in people with infection and in children
What are the important drug interactions with systemic glucocorticoids?
Increases the risk of G ulcer and bleeding when used with NSAIDs and enhance hypokalaemia in patients taking beta2 agonists, theophylline, loop or thiazide diuretics.
Efficacy may be be reduced by cytochrome P450 inducers (phenytoin, carbamazepine, rifampicin)
What are some common inhaled glucocorticoids?
Beclometasone
Budesonide
Fluticasone
What are some common indications for inhaled glucocorticoids?
Asthma (step 2)
COPD
What is the mechanism of action of inhaled glucocorticoids?
In the airways they reduce mucosal inflammation, widens the airways, and reduces mucus secretion. This improves symptoms and reduces exacerbations.
What are the important adverse effects of inhaled glucocorticoids?
Oral candidiasis
Hoarse voice
Increased risk of pneumonia
What are the contraindications of inhaled glucocorticoids?
History of pneumonia and in children
What are some topical glucocorticoids?
Hydrocortisone
Betamethasone
What is a common indications of topical glucocorticoids?
Used in inflammatory skin conditions e.g. eczema where emollients alone are ineffective
What is the mechanism of action of topical glucocorticoids?
Immunosuppression: Modify the immune response, upregulate anti-inflammatory genes and down regulate pro-inflammatory genes.
Metabolic effects: increased gluconeogenesis, increased catabolism
Mineralocorticoid effects: stimulate Na and water retention and K excretion in the renal tubule
What are the important adverse effects of topical glucocorticoids?
Local adverse effects such as skin thinning, striae, telangiectasia and contact dermatitis.
When used on the face can cause personal dermatitis and acne.
What are the contraindications of topical glucocorticoids?
Do not use where infection is present or facial lesions are present.
What are the common indications of digoxin?
AF and atrial flutter
Severe heart failure
What is the mechanism of action of digoxin?
Negatively chronotropic (reduces heart rate) and positively inotropic (increases force of contraction).
What are the important adverse effects of digoxin?
Bradycardia GI disturbance Rash Dizziness A wide range of arrhythmias can occur in digoxin toxicity
What are the contraindications of digoxin?
Second degree heart block/intermittent complete heart block
Ventricular arrhythmias
Reduced dose in renal failure
Increased risk of digoxin toxicity if hypokalaemia, hypomagnesaemia and hypercalcaemia
What are the important drug interactions of digoxin?
Loop and thiazide diuretics increase risk of digoxin toxicity.
Amiodarone, calcium channel blockers, spironolactone and quinine increase risk of digoxin toxicity
What are some common loop diuretics?
Furosemide
Bumetanide
What are some common indications of loop diuretics?
Relieves breathlessness in pulmonary oedema
Fluid overload in chronic heart failure and other oedematous states
What is the mechanism of action of loop diuretics?
Inhibits the Na/K/Cl co-transporter on the loop of Henle, stopping the water that follows from the tubular lumen into epithelial cells, having a potent diuretic effect
What are the important adverse effects of loop diuretics?
Dehydration and hypotension
Low electrolytes
Hearing loss and tinnitus
What are the contraindications to loop diuretics?
Hypovolaemia and dehydration
Hepatic encephalopathy
Hypokalaemia and hyponatraemia
Gout
What are the important drug interactions with loop diuretics?
Affect drugs that are excreted by the kidney (lithium, digoxin)
What are some potassium sparing diuretics?
Amiloride
Spironolactone
What are some common indications of potassium sparing diuretics?
Combination therapy for the treatment of hypokalaemia caused by loop diuretics
What is the mechanism of action of potassium sparing diuretics?
Weak diuretic when used alone but in combination they can counteract potassium loss. They act on the distal convoluted tubules and inhibit the reabsorption of sodium and therefore water
What are some important adverse effects of potassium sparing diuretics?
GI upset
Dizziness, hypotension and urinary symptoms.
What are the contraindications to potassium sparing diuretics?
Severe renal impairment and hyperkalaemia
Avoided in states of volume depletion
What are the important drug interactions with potassium sparing diuretics?
Do not use in combination with other potassium-elevating drugs including potassium supplements and aldosterone antagonists
Digoxin and lithium doses may need to be altered.
What are some common thiazide diuretics?
Bendroflumethiazide
Indapamide
What are the common indications of thiazide diuretics?
HTN where calcium channel blockers are contraindicated or all alternative therapies don’t work
What is the mechanism of action of thiazide diuretics?
Inhibit the Na/Cl co-transporter in the distal convoluted tubule of the nephron
What are the important adverse effects of thiazide diuretics?
Hyponatraemia
Hypokalaemia, which may lead to arrhythmias
Impotence in men
What are the contraindications with thiazide diuretics?
Hypokalaemia and hyponatraemia
Gout
What are the important drug interactions with thiazide diuretics?
Effectiveness may be reduced by NSAIDs.
What are the common dopaminergic drugs used in Parkinson’s?
Levopoda
Ropinirole
Pramipexol
What is the mechanism of action of dopaminergic drugs used in Parkinson’s?
Levodopa is a pre-cursor of dopamine.
Ropinirole and pramipexol are selective agonists for the D2 receptor
What are the important adverse effects of dopaminergic drugs used in Parkinson’s?
Nausea, drowsiness, confusion, hallucinations and hypotension
Wearing off effect where drugs stop working
What are the important contraindications to dopaminergic drugs use in Parkinson’s?
Used cautiously with elderly and those with existing cognitive or psychiatric disease and those with cardiovascular disease
What are the important drug interactions with dopaminergic rugs used in Parkinsons?
Not usually combined with antipsychotics or metoclopramide
What are some common fibrinolytics?
Alteplase
Streptokinase
What are the common indications for fibrinolytics?
Acute ischaemia stroke (within 4.5 hours stroke) Acute STEMI (but now often replaced with PCI)
What is the mechanism of action of fibrinolytics?
Catalyse the conversion of plasminogen to plasmin, which acts to dissolve fibrinous clots and re-canalise occluded vessels
What are the important adverse effects of fibrinolytics?
Nausea and vomiting
Bruising around injection site
Hypotension
Serious bleeding, allergic reaction, cardiogenic shock and cardiac arrest
What are the contraindications of fibrinolytics?
Bleeding
Intracranial haemorrhage
Previous streptokinase treatment
What are the important drug interactions with fibrinolytics?
The risk of haemorrhage is increased in patients taking anticoagulants and anti platelet agents.
What are the common indications for gabapentin and pregabalin?
Focal epilepsies
Neuropathic pain
Migraine prophylaxis
Generalised anxiety disorder
What is the mechanism of action of gabapentin and pregabalin?
Binds with voltage dependent calcium channels, preventing inflow of calcium and inhibits neurotransmitter release
What are the important adverse effects of gabapentin and pregabalin?
Drowsiness, dizziness and ataxia
What are the contraindications to gabapentin and pregabalin?
Renal impairment
What are the important drug interactions with gabapentin and pregabalin?
Avoid use with benzodiazepines due to extreme sedation
What is a common H2 receptor antagonist?
Ranitidine
What are the common indications for a H2 receptor antagonists?
Peptic ulcer disease
GORD/dyspepsia
What is the mechanism of action of H2 receptor antagonists?
Reduce gastric acid secretion
What are the important adverse effects of H2 receptor antagonists?
Generally very few side effects
GI disturbance, headache and dizziness
What are warnings of H2 receptor antagonists?
They can disguise the symptoms of gastric cancer
What are the common heparins and fondaparinux drugs?
Enoxaparin
Dalteparin
Fondaparinux
Unfractioned heparin
What are the common indications for heparin and fondaparinux?
VTE/DVT/PE
Acute coronary symptoms
What is the mechanism of action of heparins and fondaparinux?
Inactivates clotting factor Xa with or without thrombin depending on which drug you are using
What are the important adverse effects of heparins and fondaparinux?
Bleeding
Injection site reactions
Rarely: heparin-induced thrombocytopaenia
What are the contraindications to heparin and fondaparinux?
Clotting disorders
Severe uncontrolled hypertension
Recent surgery or trauma
Avoid around invasive procedures
What are the important drug interactions with heparin and fondaparinux?
Combining antithrombotic drugs increases the risk of bleeding.
What are the common types of insulin?
Insulin aspart
Insulin glargine
Biphasic insulin
Soluble insulin
What are common indications for insulin?
Insulin replacement in DM
IV in the treatment of diabetic emergencies such as DKA and hyperglycaemic hyperosmolar syndrome and for perioperative glycemic control
Alongside glucose to treat hyperkalaemia
What is the mechanism of action of insulin?
It stimulates glucose uptake from the circulation into the tissues, including skeletal muscle and fat and increases use of glucose as an energy source. Stimulates glycogen, lipid and protein synthesised inhibits gluconeogenesis and ketogenesis.
It drives K+ into the cells
What are the important adverse effects of insulin?
Hypoglycaemia
What are some contraindications to insulin?
In renal impairment, insulin clearance is reduced, and there is an increased risk of hypoglycaemia
What are the important drug interactions with insulin?
Concurrent therapy with systemic corticosteroids increases insulin requirements
What are the common iron medications?
Ferrous fumarate
Ferrous sulfate
What are the common indications for iron?
Treatment and prophylaxis of iron-deficiency anaemia
What is the mechanism of action of iron?
It is absorbed by the duodenum and jejunum. Once absorbed into the blood stream it is bound by transferrin, where it is transported to either the bone marrow or stored as ferritin.
What are the important adverse effects of iron?
GI upset, stools may turn black, nausea, epigastric pain, constipation and diarrhoea
What are the contraindications of iron?
Oral iron therapy may exacerbate bowel symptoms in patients with intestinal disease including IBD, diverticular disease and intestinal strictures.
IV iron should be used with caution in patients with an atopic predisposition
What are the important drug interactions with iron?
Iron can reduce the absorption of other drugs such as levothyroxine and bisphosphonates.
What are some bulk-forming laxatives?
Ispaghula husk
Methylcellulose
Sterculia
What are the common indications for bulk-forming laxatives?
Constipation and faecal importation
Mild chronic diarrhoea
What is the mechanism of action of bulk-forming laxatives?
They contain a hydrophilic substance, which is not absorbed into the gut. This attracts water into the stool and increases its mass. Increased stool bulk stimulates peristalsis.
What are the important adverse effects of bulk-forming laxatives?
Generally well tolerated. Common adverse effects include mild abdominal distention and flatulence.
Rare but serious: faecal importation and GI obstruction
What are the important contraindications to bulk-forming laxatives?
Not used in patients with subacute or established intestinal obstruction or faecal impactation. generally not used in patients with ileus
What are some common osmotic laxatives?
Lactulose
Macrogol
Phosphate enema
What are the common indications of osmotic laxatives?
Constipation and faecal impactation
Bowel preparation prior to surgery or endoscopy
Hepatic encephalopathy
What is the mechanism of action of osmotic laxatives?
Based on osmotically active substances (sugars or alcohols) that are not digested, they hold water in the stool, maintaining its volume and stimulating peristalsis.
What are the important adverse effects of osmotic laxatives?
Flatulence, abdominal cramps and nausea.
Diarrhoea is possible.
Phosphate enemas can cause local irritation and electrolyte disturbances
What are the contraindications of osmotic laxatives?
Intestinal obstruction
Phosphate enemas can cause significant fluid shifts so should be used in caution in heart failure, ascites and electrolyte disturbance
What are the important drug interactions with osmotic laxatives?
Can slightly increase the effects of warfarin
What are some common stimulant laxatives?
Senna
Bisacodyl
Glycerol suppositories
Docusate sodium
What are some common indications for stimulant laxatives?
Constipation
Suppositories for faecal impactation
What is the mechanism of action for stimulant laxatives?
Stimulant laxatives increase water and electrolyte secretion from the colonic mucosa, thereby increasing volume of colonic content and stimulating peristalsis
What are the important adverse effects of stimulant laxatives?
Abdominal pain or cramping may occur. Diarrhoea
What are the contraindications of stimulant laxatives?
Intestinal obstruction - could induce perforation
Rectal preparations are usually avoided if haemorrhoids or anal fissures are present
What are the common indications of lidocaine?
Local anaesthetic
What is the mechanism of action of lidocaine?
Blocks voltage-gated sodium channels on the surface membrane of the cell. Prevents initiation and propagation of action potentials in nerves and muscle.
What are the important adverse effects of lidocaine?
Initial stinging sensation
Drowsiness, restlessness, tremor and fits
What are the contraindications of lidocaine?
The dose should be reduced in states of reduced cardiac output
What are the important drug interactions with lidocaine?
Co-administration with a vasoconstrictor (adrenaline) produces a desirable interaction that may prolong the local anaesthetic effect
What are the common macrolides?
Clarithromycin
Erythromycin
Azithromycin
What are the common indications for macrolides?
Respiratory and skin and soft tissue infections
Severe pneumonia
Eradication of H.pylori in combination with PPI and either amoxicillin and metronidazole
What is the mechanism of action of macrolides?
Inhibit bacterial protein synthesis
What are the important adverse effects of macrolides?
Irritant, causing nausea, vomiting abdo pain and diarrhoea.
Allergy, antibiotic-associated colitis, cholestatic jaundice, prolongation of the QT interval and ototoxicity
What are the contraindications of macrolides?
Macrolide hypersensitivity
Caution required in severe hepatic impairment and dose reduction in severe renal impairment
What are the important drug interactions of macrolides?
Erythro- and clarithromycin inhibit cytochrome P450 enzymes. Increases plasma concentrations and risk of adverse effects with drugs metabolised by P450 enzymes (warfarin, statins)
Use caution with other drugs that prolong QT interval
What is the common indication for metformin?
T2DM
What is the mechanism of action of metformin?
Lowers blood glucose by increasing the response (sensitivity) to insulin. Suppresses hepatic glucose production, increases glucose uptake and utilisation by skeletal muscle and suppresses intestinal glucose absorption
What are the important adverse effects of metformin?
GI upset, nausea, vomiting, taste disturbance, anorexia and diarrhoea.
Lactic acidosis
What are the contraindications to metformin?
Severe renal impairment AKI Severe tissue hypoxia (cardiac or respiratory failure or MI) Acute alcohol intoxication Caution in hepatic impairment
What are the important drug interactions to metformin
Must be withheld before and for 48 hours after injection of IV contrast media.
Other drugs which impair renal function should also be used with caution (ACE inhibitors, NSAIDs, diuretics)
Prednisolone, thiazide and loop diuretics elevate blood glucose, hence oppose the actions and reduce the efficacy of metformin
What are the common indications of methotrexate?
Rheumatoid arthritis
As part of chemotherapy in leukaemia, lymphoma and some solid tumours
To treat severe psoriasis
What is the mechanism of action of methotrexate?
Inhibits dihydrofolate reductase, which prevents cellular replication
What are the important adverse effects of methotrexate?
Mucosal damage and bone marrow suppression.
Hypersensitivity reaction.
Long term use can cause hepatic, cirrhosis or pulmonary fibrosis
What are the contraindications of methotrexate?
Pregnancy
Severe renal impairment
Abnormal liver function
What are the important drug interactions of methotrexate?
Methotrexate toxicity is more likely if it is prescribed with drugs that inhibit its renal excretion (NSAIDs, penicillins).
Co-prescription with other folate antagonists (trimethoprim, phenytoin) increases the risk of haematological abnormalities
What are the common indications of metronidazole?
Antibiotic-associated colitis caused by C-diff.
Oral infections (dental abscess) or aspiration pneumonia
Surgical and gynaecological infections
Protozoal infections
What is the mechanism of action of metronidazole?
In anaerobic bacteria, reduction of metronidazole generates nitroso free radical. This binds to DNA, reducing synthesis and causing widespread damage, DNA degradation and cell death.
What are the important adverse effects of metronidazole?
GI upset (nausea and vomiting) Immediate and delayed hypersensitivity reactions Used long term - peripheral and optic neuropathy, seizures and encephalopathy
What are the contraindications of metronidazole?
Dose should be reduced in severe liver disease
Do not drink alcohol with it
What are the important drug interactions of metronidazole?
Inhibitory effect on cytochrome P450 enzymes, reducing metabolism of warfarin and phenytoin.
Increases the risk of toxicity of lithium
What the common indications of naloxone?
Opioid toxicity associated with respiratory and/or neurological depression
What is the mechanism of action of naloxone?
Binds to opioid receptors which it acts as a competitive antagonist. It has no effect in the absence of exogenous opioid, however if an opioid is present, naloxone displaces it.
What are the contraindications of naloxone?
Opioid dependence
Lower doses should be used in palliative care
What is the common indication of Nicorandil?
For prevention and treatment of chest pain in people with stable angina (after beta-blockers and CCBs)
What is the mechanism of action of Nicorandil?
Causes arterial and venous vasodilation through its action as a nitrate and by activating K+-ATP channels and inactivating Ca channels, causing smooth muscle contraction, relaxation and vasodilation.
What are the important adverse effects of Nicorandil?
Flushing, dizziness and headache.
Nausea, vomiting and hypotension.
GI, skin or mucosal ulceration
What are the contraindications of Nicorandil?
Poor left ventricular function
Hypotension
Pulmonary oedema
What are the important drug interactions of Nicorandil?
As with nitrates, the hypotensive side effects of nicorandil are significantly enhanced by phosphodiesterase inhibitors (sildenafil).
What is the common indication for nitrofurantoin?
Uncomplicated lower UTI
What is the mechanism of action of nitrofurantoin?
Its active metabolite damages bacterial DNA and causes cell death
What are the important adverse effects of nitrofurantoin?
GI upset (nausea and diarrhoea) and immediate and delayed hypersensitivity reactions.
Can turn urine dark yellow or brown.
Long term use - chronic pulmonary reactions, hepatitis and peripheral neuropathy.
What are the contraindications of nitrofurantoin?
Pregnant women towards term or for babies in the first 3 months of life.
Renal impairment
What are some common NSAIDs?
Naproxen
Ibuprofen
What are the common indications for NSAIDs?
Mild to moderate pain
Pain related to inflammation
What is the mechanism of action of NSAIDs?
Inhibit synthesis of prostaglandins from arachidonic acid by inhibiting COX
What are the important adverse effects of NSAIDs?
GI toxicity, renal impairment and increased risk of cardiovascular events.
Hypersensitivity reactions and fluid retention
What are the contraindications of NSAIDs?
Severe renal impairment, heart failure, liver failure and NSAID hypersensitivity.
Peptic ulcer disease, GI bleeding, cardiovascular disease, renal impairment
What are the important drug interactions with NSAIDs?
Many drugs increase the risk of NSAID-related adverse effects including GI ulceration: aspirin, corticosteroids; GI bleeding: anticoagulants, SSRIs, venlafaxine; Renal impairment: ACE inhibitors, diuretics
What are the common ocular lubricants?
Hypromellose, carbomers, liquid and white soft paraffin
What are the common indications for ocular lubricants?
Keratoconjunctivitis sicca and Sjogren’s syndrome
What is the mechanism of action of ocular lubricants?
Soothing effect and help protect the eye surfaces from abrasive damage
What are the important adverse effects of ocular lubricants?
Few side effects other than mild stinging on application and temporary blurring of vision.
May incite inflammatory reaction in some patients
What are the common indications for oestrogen and progestogens?
Hormonal contraception
Hormone replacement therapy
What is the mechanism of actions of oestrogen and progestogens?
Given to suppress LH/FSH release and hence ovulation
What are the important adverse effects of oestrogen and progestogens?
Irregular bleeding and mood changes.
Can double the risk of VTE, increase the risk of CVD and stroke.
Increased risk of breast and cervical cancer
What are the important contraindications of oestrogen and progestogens?
Breast cancer
Increased risk of VTE or CVD
What are the important drug interactions with oestrogen and progestogens?
Concurrent use of cytochrome P450 inhibitors (rifampicin) may reduce the efficacy of hormonal contraception, particularly progestogen-only forms
What are some common opioid compound preparations?
Co-codamol
Co-dydramol
What are some common indications of opioid compound preparations?
Mild-moderate pain - second on the WHO pain ladder
What is the mechanism of action of opioid compound preparations?
Paracetamol : weak COX inhibitor
Opioid: agonists of opioid u-receptors
What are the important adverse effects of opioid compound preparations?
Nausea, constipation and drowsiness
What are the contraindications of opioid compound preparations?
Significant respiratory disease
Doses reduced in renal impairment, hepatic impairment and in the elderly
What are the important drug interactions with opioid compound preparations?
Should not ideally be used with other sedating drugs (antipsychotics, benzodiazepines and tricyclic antidepressants)
What are some common strong opioids?
Morphine, oxycodone
What are the common indications for strong opioids?
Acute severe pain (post-op and MI)
Chronic pain (rung 3 of WHO pain ladder)
Breathlessness in end of life care
Relieve breathlessness and anxiety in acute pulmonary oedema alongside oedema, furosemide and nitrates
What is the mechanism of action of strong opioids?
Activation of opioid (mu) receptors, reduce sympathetic nervous system activity
What are the important adverse effects of strong opioids?
Respiratory depression Neurological depression Nausea and vomiting Pupillary constriction Constipation, itching Tolerance and dependence
What are the contraindications of strong opioids?
Reduced dose in hepatic failure, renal impairment and the elderly.
Respiratory failure and biliary colic
What are important drug interactions with strong opioids?
Should not be used with other sedating drugs (antipsychotics, benzodiazepines and tricyclic antidepressants)
What are some weak opioids?
Tramadol
Codeine
Dihydrocodeine
What is the common indication for weak opioids?
Mild-moderate pain including post-op pain (second rung of WHO pain ladder)
What is the mechanism of action of weak opioids?
Agonists of opioid (mu) receptors
What are the important adverse effects of weak opioids?
Nausea, constipation, dizziness and drowsiness
Neurological and respiratory depression
Codeine and dihydrocodeine must never be given IV
What are the contraindications of weak opioids?
Significant respiratory disease
Doses should be reduced in renal impairment and hepatic impairment and in the elderly.
Tramadol lowers the seizure threshold so is best to avoid in patients with epilepsy and certainly should not be used in those with uncontrolled epilepsy
What are the important drug interactions with weak opioids?
Other sedating drugs (antipsychotics, benzodiazepines and tricyclic antidepressants)
Tramadol should not be used with other drugs that lower the seizure threshold, such as SSRIs and tricyclic antidepressants
What are the common indications for oxygen?
To increase tissue oxygen delivery in states of hypoxaemia
To accelerate reabsorption of pleural gas in pneumothorax
To reduce the half-life of carboxyhemoglobin in carbon monoxide poisoning
What is the mechanism of action of oxygen?
Increases delivery of oxygen to the tissues.
Accelerates the diffusion of nitrogen out of the body.
Shortens the half-life of carboxyhaemoglobin
What are the important adverse effects of oxygen?
Dry throat
What are the contraindications of oxygen?
Chronic type 2 respiratory failure
Heat source or naked flame
What are the common indications of paracetamol?
Acute and chronic pain, first rung on the WHO ladder.
Paracetamol is an antipyretic that can reduce fever and its associated symptoms
What is the mechanism of action of paracetamol?
Poorly understood - weak COX inhibitor
What are the important adverse effects of paracetamol?
Very few side effects. In overdose, can cause liver failure
What are the contraindications of paracetamol?
Dose should be reduced in people at increased risk of liver toxicity (chronic excessive alcohol use, malnutrition, low body weight, severe hepatic impairment)
What are some common penicillins?
Benzylpenicillin, piperacillin with Tazobactam (Tazocin), amoxicillin, co-amoxiclav, flucloxacillin
What are the common indications for penicillin?
Streptococcal and staphylococcal infection, tonsillitis, pneumonia, endocarditis and skin and soft tissue infections Tetanus Meningitis, septicaemia H.pylori-associated peptic ulcers UTI Osteomyelitis and septic arthritis
What is the mechanism of action of penicillin?
Weakens cell walls, preventing them from maintaining an osmotic gradient. Uncontrolled entry of water into bacteria causes cell swelling, lysis and death. Contain a beta-lactam ring, which is responsible for their antimicrobial activity
What are the important adverse effects of penicillin?
GI upset.
Penicillin allergy.
Liver toxicity
Central nerve system toxicity
What are the contraindications of penicillin?
Dose reduction in renal impairment
History of penicillin allergy
What are the important drug interactions with penicillin?
Reduce renal excretion of methotrexate, increasing the risk of toxicity.
Tazocin and co-amoxiclav can enhance the anticoagulant effect of warfarin
What are the common indications for phenytoin?
To control seizures in status epilepticus where benzodiazepines are ineffective
What is the mechanism of action of phenytoin?
Incompletely understood.
Reduced neuronal excitability, binds to neuronal Na channels in their inactive state, prolonging inactivity and preventing Na influx into the neuronal.
What are the important adverse effects of phenytoin?
Change in appearance: skin coarsening, acne, hirsutism and gum hypertrophy.
Haematological disorders and osteomalacia.
Hypersensitivity
What are the contraindications to phenytoin?
Therapeutic dose is low, implying that the safety margin between therapeutic and toxic doses is narrow. Dose should be reduced in hepatic impairment.
Pregnancy
What are the important drug interactions with phenytoin?
Reduces plasma concentrations and efficacy of drugs metabolised by P450 enzymes (warfarin and oestrogen and progestogens).
Phenytoin concentration and adverse effects are increased by cytochrome P450 inhibitors (amiodarone, diltiazem and fluconazole)
The efficacy of antiepileptic drugs is reduced by drugs that lower the seizure threshold (SSRIs, tricyclic antidepressants, antipsychotics and tramadol)
What is a common phosphodiesterase inhibitor?
Sildenafil
What are the common indications for phosphodiesterase inhibitors?
Erectile dysfunction
Primary pulmonary hypertension
What is the mechanism of action of phosphodiesterase inhibitors?
Selective inhibitor for DPE-type-5. Sildenafil increases cGMP concentrations, improving penile blood flow and erection quality
What are the important adverse effects of phosphodiesterase inhibitors?
Flushing, headache, dizziness and nasal congestion.
Hypotension, tachycardia and palpitations and a small associated risk of vascular events.
What are the important contraindications of phosphodiesterase inhibitors?
Recent stroke or ACS or significant cardiovascular disease. Lower dose needed in people with hepatic or renal impairment
What are the important drug interactions of phosphodiesterase inhibitors?
Do not give drugs that increase nitric oxide, particular nitrates or nicorandil.
Prescribe sildenafil with caution in patients taking other vasodilators.
Plasma concentrations and adverse effects of sildenafil are increased by cytochrome P450 inhibitors (amiodarone, diltiazem and fluconazole)
What are some common types oral potassium?
Potassium chloride and potassium bicarbonate
What are some common indications for oral potassium?
Treatment and prevention of potassium depletion (low serum potassium concentration)
What are the important adverse effects of oral potassium?
Not very well tolerated, they are unpalatable and cause GI disturbance including nausea, vomiting, pain diarrhoea and flatulence. Overtreatment may lead to hyperkalaemia and a resultant risk of arrhythmias
What are the important contraindications of oral potassium?
Used with caution in renal impairment, avoided in severe renal impairment.
What are the important drug interactions with oral potassium?
Additive effects with other potassium-elevated drugs, including IV potassium chloride, aldosterone antagonists, potassium-sparing diuretics, ACE inhibitors and angiotensin receptor blockers
What are some common prostaglandin analogue eye drops?
Latanoprost
Bimatoprost
What are the common indications for prostaglandin analogue eye drops?
First-line agents to lower intraocular pressure in open-angle glaucoma and ocular hypertension.
What is the mechanism of action of prostaglandin analogue eye drops?
Analogues of prostaglandin reduce intraocular pressure by increasing outflow of aqueous humour via the oveoscleral pathway.
What are the important adverse effects of prostaglandin analogue eye drops?
Few systemic side effects. Local effects: blurred vision, conjunctival reddening and ocular irritation and pain. May also cause a permanent change in eye colour.
What are the important contraindications of prostaglandin analogue eye drops?
Aphakia
Iritis
Uveitis
Macular oedema
What are some common proton pump inhibitors?
Lanzoprazole
Omeprazole
Pantoprazole
What are some common indications for PPIs?
Prevention and treatment of peptic ulcer disease, including NSAID-associated ulcers
Relief of dyspepsia and GORD
Eradication of H.pylori infection
What is the mechanism of action of PPIs?
Reduce gastric acid secretion. Act by irreversibly inhibiting H+/K+-ATPase in gastric parietal cells.
What are the important adverse effects of PPIs?
GI disturbances and headache
Long term use - hypomagnesaemia
What are the contraindications of PPIs?
May disguise symptoms of gastric cancer so ensure you ask about alarm symptoms.
Long term - osteoporosis and increase the risk of fracture
What are the important drug interactions with PPIs?
Reduce the antiplatelet effect of clopidogrel by decreasing its activation by cytochrome P450 enzymes.
What are some common quinolones?
Ciprofloxacin
Moxifloxacin
Levofloxacin
What are some common indications of quinolones?
UTI
Severe GI infection (shigella/campylobacter)
LRTI
Ciprofloxacin is the only oral antibiotic in common use with activity against pseudomonas aeruginosa
What is the mechanism of action of quinolones?
Kill bacteria by inhibiting DNA synthesis
Bacteria rapidly develop resistance
What are the important adverse effects of quinolones?
Generally well tolerated - GI upset (nausea and diarrhoea)
Hypersensitivity reaction
Neurological effects (lowering of seizure threshold and hallucinations)
Prolong the QT interval and increase risk of arrhythmias
Promote C.diff colitis
What are the contraindications of quinolones?
People with or at risk of seizures
Who are growing
Risk factors for QT prolongation
What are the important drug interactions with quinolones?
Ciprofloxacin inhibits cytochrome P450 enzymes, increasing toxicity of some drugs (theophylline)
Co-prescription of NSAIDs increases the risk of seizures and of prednisolone increases the risk of tendon rupture
What are some common statins?
Simvastatin
Atorvastatin
Pravastatin
What are some common indications for statins?
Primary prevention of CVD
Secondary prevention of CVD
Primary hyperlipidaemia
What is the mechanism of action of statins?
They inhibit 3-hydroxy-3-methyl-glutaryl coenzyme A (HMG CoA) reductase, an enzyme involved in making cholesterol
What are the important adverse effects of statins?
Headache, GI disturbance
Simple aches, serious myopathy or, rarely, rhabdomyolysis
Rise in liver enzymes
What are some contraindications of statins?
Used in caution with hepatic impairment.
Reduced dose in renal impairment
Not used in pregnancy or breastfeeding
What are some important drug interactions with statins?
Metabolism of statins is reduced by cytochrome P450 inhibitors, such as amiodarone, diltiazem, itraconazole, macrolides and protease inhibitors
What are some common sulphonylureas?
Gliclazide
What is the common indication for sulphonylureas?
T2DM
What is the mechanism of action of sulphonylureas?
Lower blood glucose by stimulating pancreatic insulin secretion
What are the important adverse effects of sulphonylureas?
GI upset (nausea, vomiting, diarrhoea, constipation) usually mild and infrequent
Hypoglycaemia
Rare hypersensitivity reactions
What are the contraindications of sulphonylureas?
Reduced dose in hepatic and renal impairment
What are some important drug interactions with sulphonylureas?
Risk of hypoglycaemia is increased by co-prescription of other antidiabetic drugs including metformin, thiazolidinediones and insulin.
The efficacy of sulphonylureas is reduced by drugs that elevate blood glucose (prednisolone, thiazide and loop diuretics)
What are some common tetracyclines?
Doxycycline
Lymecycline
What are some common indications for tetracyclines?
Acne vulgaris
LRTI including infective exacerbations of COPD, pneumonia and atypical pneumonia
Chlamydial infection including PID
What is the mechanism of action of tetracyclines?
They inhibit bacterial protein synthesis
What are the important adverse effects of tetracyclines?
Nausea, vomiting and diarrhoea.
Hypersensitivity reactions
Oesophageal irritation, ulceration and dysphagia
Photosensitivity and discolouration and/or hypoplasia of tooth enamel if prescribed for children
What are the contraindications of tetracyclines?
Pregnancy
Breastfeeding
Children <12 years of age
Renal impairment
What are some important drug interactions with tetracyclines?
Should not be given within 2 hours of calcium, antacids or iron, they prevent antibiotic absorption
Can enhance the anticoagulant effect of warfarin
What is a common thiazolidinedione?
Pioglitazone
What are the common indications for a thiazolidinedione?
As a single agent in overweight patients where metformin is contraindicated or not tolerated
Added as a second agent to metformin or a sulphonylurrea
Added as a third agent to metformin and a sulphonylurea
What is the mechanism of action of thiazolidinediones?
Insulin sensitisers.
What are the important adverse effects of thiazolidinediones?
Weight gain.
GI upset, anaemia and minor neurological disturbances (dizziness, headache and disturbed vision)
Oedema and cardiac failure
Bladder cancer, bone fractures
What are the contraindications of thiazolidinediones?
Heart failure and CVD.
Bladdercancer
Caution in use in elderly and hepatic impairment
What are the important drug interactions of thiazolidinediones?
Usually prescribed with other anti diabetic drugs, so adverse effects such as hypoglycaemia and cardiac failure are increased
What are some common thyroid hormones?
Levothyroxine
Liothyroxine
What are the common indications for thyroid hormones?
Primary hypothyroidism
Hypothyroidism secondary to hypopituitarism
What is the mechanism of action of thyroid hormones?
Regulate metabolism and growth. Levothyroxine is synthetic T4, liothyroxine is synthetic T3
What are the important adverse effects of thyroid hormones?
Usually due to excessive doses so are similar to hyperthyroidism
What are the contraindications to thyroid hormones?
Coronary artery disease.
In hypopituitarism, corticosteroids must be started first to avoid precipitating Addisonian crisis
What are the important drug interactions with thyroid hormones?
Absorption reduced by antacids, calcium or iron salts, need to separated by 4 hours.
Increased dose may be needed in patients taking cytochrome P450 inducers (phenytoin, carbamazepine).
Changes in metabolism caused by these drugs can increase insulin or oral hypoglycaemic requirements in DM and enhance the effects of warfarin
What is the common indications for trimethoprim?
UTI
What is the mechanism of action of trimethoprim?
Inhibits bacterial folate synthesis, slowing bacterial growth
What are the important adverse effects of trimethoprim?
GI upset (nausea, vomiting, sore mouth) and skin rash are common. Can cause haematological disorders and hyperkalaemia
What are the contraindications of trimethoprim?
First trimester of pregnancy
Folate deficiency
Dose reduced in elderly, renal impairment, neonates and HIV infection
What are the important drug interactions with trimethoprim?
Use with potassium elevating drugs (ACEi, aldosterone antagonists and angiotensin receptor blockers) can cause hyperkalaemia.
Use with other folate antagonists (methotrexate) and drugs that increase folate metabolism (phenytoin) increases the risk of adverse haematological effects.
Can increase anticoagulant effect on warfarin
What are some common valproate?
Sodium valproate and valproic acid
What are the common indications for valproate?
Epilepsy
Bipolar disorder, for the acute treatment of a manic episode and prophylaxis against recurrence
What is the mechanism of action of valproate?
Not fully understood. Inhibits neuronal sodium channels, increases GABA
What are the important adverse effects of valproate?
GI upset (nausea, gastric irritation, diarrhoea)
Neuronal and psychiatric effects (tremor, ataxia and behavioural disturbances)
Thrombocytopaenia and increase in liver enzymes
Rare, life threatening idiosyncratic adverse effects: severe liver injury, pancreatitis, bone marrow failure and anti epileptic hypersensitivity syndrome
What are the contraindications to valproate?
Women of child-bearing age, conception, pregnancy
Hepatic and renal impairment
What are the important drug interactions with valproate?
Inhibits cytochrome P450 enzymes, increasing plasma concentration and toxicity of drugs metabolised by P450 (warfarin)
Concentration reduced by cytochrome P450 inducers (phenytoin, carbamazepine, carbapenems)
The efficacy of antiepileptic drugs is reduced by drugs that lower seizure threshold (SSRIs, tricyclic antidepressants, antipsychotics, tramadol)
What are the common indications for vancomycin?
Treatment of gram positive infection (severe endocarditis or if penicillins can’t be used)
Treatment of antibiotic-associated colitis caused by C.diff
What is the mechanism of action of vancomycin?
Inhibiting the synthesis of the cell wall of gram-positive bacteria
What are the important adverse effects of vancomycin?
Most common is thrombophlebitis (inflammation round cannula)
If infused rapidly anaphylactoid reaction can occur.
IV vancomycin can cause nephrotoxicity, ototoxicity and blood disorders
What are the contraindications of vancomycin?
Renal impairment and the elderly
What are the important drug interactions with vancomycin?
Increases the risk of ototoxicity and/or nephrotoxicity when prescribed with aminoglycosides, loop diuretics or ciclosporin
What are the common indications for warfarin?
Prevent clot extension and recurrence in DVT and PE
Prevent embolic complications in AF
Prevent embolic complications after heart valve replacement
What is the mechanism of action of warfarin?
Inhibits vitamin K epode reductase, preventing reactivation of Vitamin K and coagulation factor synthesis
What are the important adverse effects of warfarin?
Bleeding
What are the contraindications to warfarin?
Immediate risk of haemorrhage
Liver disease
Pregnancy
What are the important drug interactions of warfarin?
Cytochrome P450 inhibitors (flucanazole, macrolides, protease inhibitors) decrease warfarin metabolism and increase bleeding risk
Cytochrome P450 inducers (phenytoin, carbamazepine, rifampicin) increase warfarin metabolism and risk of clots
Many antibiotics can increase anticoagulation in patients with warfarin
What are the Z-drugs?
Zopiclone
Zolpidem
What are the common indications for Z drugs?
Short-term treatment of insomnia
What is the mechanism of action of Z drugs?
Similar to Benzos. Facilitate and enhance the binding of GABA to the GABA receptor.
What are the important adverse effects of Z drugs?
Daytime sleepiness Rebound insomnia CNS effects (headache, confusion, nightmares) Zopiclone : taste disturbance. Zolpidem: GI upset Dependence and withdrawal symptoms
What are the contraindications of Z drugs?
Elderly
Obstructive sleep apnoea
Respiratory muscle weakness
Respiratory depression
What are the important drug interactions with Z drugs?
P450 inhibitors can enhance sedation.
P450 inducers can impair sedation.
