Prescribing safety assessment

Question 1

List drugs which can cause urinary retention

Answer 1

• Opioid analgesia, especially post-op
• Anticholinergics - antipsychotics, antidepressants, respiratory anti-muscarinics, detrusor relaxants
• General anaesthetics
• Alpha-adrenoreceptor agonists
• Benzodiazepines
• NSAIDs
• Calcium-channel blockers
• Antihistamines
• Alcohol

Question 2

List drugs which can cause confusion

Answer 2

• Opioids, benzodiazepines, Z-drugs
• Anticholinergics - antipsychotics, antidepressants, respiratory anti-muscarinics, detrusor relaxants
• Anticonvulsants
• Histamine H2 receptor antagonists
• Digoxin
• Beta-blockers
• Steroids
• NSAIDs
• Antibiotics - fluoroquinolones
• Lithium

Question 3

Monitoring required for statins

Answer 3

Liver enzymes measured pre-treatment, at 3 months and at 12 months

If transaminases raised but within 3x upper limit of normal no need to stop statin
If more than 3x upper limit of normal should discontinue

Question 4

When should gentamicin concentration be measured?

Answer 4

Trough levels - just before next dose

Question 5

If peak gentamicin concentration and trough gentamicin concentration are increased, how should the gentamicin prescription be adjusted?

Answer 5

Decrease dose, increase interval between doses

Question 6

Drug of choice for symptoms of acute heart failure (oedema, SOB)

Answer 6

IV furosemide

Question 7

Management for hypoglycaemia with reduced consciousness

Answer 7

IV glucose 20% - 50-100ml over 15 minutes
(10% if not available - 100-200ml over 15 minutes)

Question 8

Oral antibiotic for moderate - severe acne

Answer 8

Lymecycline
Oxytetracycline
Tetracycline

Question 9

List drugs which can cause hyperkalaemia

Answer 9

ACE inhibitors
ARBs
Potassium-sparing diuretics
Heparins
Beta-blockers
Digoxin
NSAIDs
Cyclosporin
Tacrolimus

Question 10

List drugs which should be stopped prior to surgery and when they should be stopped

Answer 10

Antiplatelets - stop 7-10 days prior to surgery, use LMWH/UFH instead if high risk
Combined hormonal contraceptive - stop 4 weeks prior to surgery (major elective surgery, surgery involving immobilisation of lower limbs, surgery to pelvis) and use alternative contraceptive
HRT - stop 4-6 weeks prior to surgery (major surgery under general anaesthesia)
Oral anti-hyperglycaemics - sometimes omit doses?

Question 11

List drugs which can cause hyperglycaemia

Answer 11

Steroids
Thiazide diuretics
Antipsychotics
Phenytoin
Protease inhibitors
Cyclosporin
Tacrolimus

Question 12

List drugs which can cause hyponatraemia

Answer 12

SSRIs
Thiazide diuretics (+ other diuretics)
Antipsychotics
Carbamazepine
Others (less common) - opioids, ACEi, ARBs, PPIs, anticonvulsants, amiodarone, theophylline, dopamine antagonists, antidiabetics, NSAIDs, MDMA, desmopressin, oxytocin

Question 13

Management of acute alcohol withdrawal

Answer 13

Long-acting benzodiazepine - chlordiazepoxide, diazepam
(+ lorazepam if seizures occur)

Prevention of Wernicke’s - IV pabrinex then oral thiamine

Question 14

List drugs which can cause hypoglycaemia

Answer 14

Insulin
Sulphonylureas - highest risk of oral antihyperglycaemics
Other oral antihyperglycaemics (DDP-4 inhibitors, pioglitazone, metformin, SGLT2 inhibitors, GLP-1 mimetics) usually low risk but can contribute when combined

Others:
Beta-blockers
Fluoroquinolones
ACE inhibitors

Question 15

How should contraception be managed in a woman taking the COCP and a liver enzyme-inducing drug concurrently?

Answer 15

Use alternative contraception for duration of treatment and until 4 weeks after enzyme-inducing drug stopped

Question 16

How should contraception for a woman taking a teratogenic drug be managed?

Answer 16

Preferred method is copper or progestogen coil

Question 17

List drugs which can precipitate/worsen heart failure

Answer 17

NSAIDs
Anaesthesia
Oral antihyperglycaemics - metformin, pioglitazone, DPP-4 inhibitors
Antiarrhythmics - flecainide, dronedarone
Alpha blockers - doxazosin
Calcium channel blockers - diltiazem, verapamil, nifedipine
Antifungals - intraconazole, amphotericin B
Chemotherapy - doxorubicin, cyclophosphomide, mitomycin
Biologics
Antiepileptics - carbamazepine
Citalopram
Antiparkinsons
Antipsychotics - clozapine
Lithium
Hydroxychloroquine

Question 18

List drugs that can cause cough

Answer 18

ACE inhibitors
Beta-blockers
NSAIDs
Calcium channel blockers

Question 19

List drugs that can cause oedema

Answer 19

Calcium channel blockers - amlodipine, nifedipine, felodipine
Insulin
Pioglitazone
NSAIDs
Steroids
Sex hormones e.g. COCP, HRT
Antipsychotics
Bisphosphonates
Chemotherapy
Anticonvulsants - gapapentin, pregabalin
MAOIs

Question 20

List drugs which can cause hypokalaemia

Answer 20

Diuretics - thiazide + loop
Beta-agonists e.g. salbutamol, salmeterol
Insulin
Theophylline
Steroids
Laxatives
Antibiotics - penicillin, aminoglycosides
Antifungals - amphotericin B
Aciclovir
Verapamil overdose

Question 21

List drugs that can cause myopathy

Answer 21

Statins (+ drugs which interact with and increase exposure to statins)
Steroids
Immunosuppressants
Antibiotics - ciprofloxacin, norfloxacin, ofloxacin
Chemotherapy agents - docetaxel, vincristine
Bisphosphonates

Question 22

List drugs which commonly cause diarrhoea

Answer 22

PPIs
H2 receptor antagonists
SSRIs
Antibiotics
Metformin, sulphonylureas
Methotrexate
Iron
NSAIDs
Magnesium containing antacids

Question 23

List drugs that commonly cause dyspepsia

Answer 23

Aspirin
NSAIDs
Iron
Antibiotics
Alpha-blockers
Antimuscarinics
Benzodiazepines
Beta-blockers
Bisphosphonates
Calcium channel blockers
Steroids
Nitrates
Theophylline
Tricyclic antidepressants

Question 24

List drugs that commonly cause bradycardia

Answer 24

Beta-blockers
Calcium channel blockers
Alpha-blockers
Digoxin
Phenytoin
Tricyclic antidepressants
Lithium

Question 25

List drugs that can cause bleeding

Answer 25

Anticoagulants - heparin, warfarin, DOACs Antiplatelets - aspirin, clopidogrel, dipyridamole, prasugrel, ticlopidine NSAIDs SSRIs/SNRIs + Drugs that interact with and increase exposure (e.g. warfarin and liver enzyme inhibitors)

Question 26

List drugs that commonly cause constipation

Answer 26

Opiates Anticholinergics Antimuscarinics Antimotility e.g. loperamide Antipsychotics e.g. clozapine Benzodiazepines Iron Tricyclic antidepressants Antihistamines

Question 27

List drugs which should be witheld/altered in AKI

Answer 27

Drugs which can cause renal toxicity: Contrast media ACEi NSAIDs Diuretics ARBs Bisphosphonates Colchicine Drugs which may accumulate due to reduced renal excretion and cause toxicity: Opioids Benzodiazepines Antibiotics - aminoglycosides, penicillins, tetracyclines, trimethoprim, vancomycin Antifungals - amphotericin, fluconazole Antivirals - aciclovir, ganciclovir Phenytoin Pregabalin, gapapentin Levetiracetam Hypoglycaemis Calcineurin inhibitors - ciclosporin, tacrolimus Methotrexate Allopurinol Antihistamines Antipsychotics Digoxin Statins, fibrates Lithium LMWH Warfarin Risk of hyperkalaemia: Trimethoprim ACEi/ARBs Potassium-sparing diuretics Calcineurin inhibitors - ciclosporin, tacrolimus Digoxin

Question 28

When is oxycodone used instead of morphine for pain management?

Answer 28

Morphine not tolerated e.g. nausea, anorexia, GI discomfort Severe renal failure - GFR below 30

Question 29

Describe a typical analgesia regimen for pain in palliative care

Answer 29

Initially titrate dose of regular immediate-release morphine Breakthrough doses of immediate-release morphine given at one tenth to one sixth of regular 24-hour dose, repeated 2-4 hourly as required Can also use nasal, buccal or sublingual fentanyl for breakthrough Once pain controlled can be switched to equivalent modified- release morphine with 12-hourly or 24-hourly administration Can give continuous subcutaneous infusion of morphine (or diamorphine) if patient becomes unable to swallow Can give transdermal fentanyl or buprenorphine, not used for acute pain or rapidly changing analgesia requirements as long time to steady state, with immediate-release morphine or nasal/buccal/sublingual fentanyl given for breakthrough pain

Question 30

Describe VTE prophylaxis for surgical patients

Answer 30

Pharmacological prophylaxis for patients undergoing general or orthopaedic surgery LMWH suitable for all general/orthopaedic - dalteparin, enoxaparin (dose and regimen dependent on risk level) UFH better if renal impairment Specific regimens for elective knee and hip replacements

Question 31

Describe VTE prophylaxis for medical patients

Answer 31

Acutely ill and high risk VTE - pharmacological prophylaxis with LMWH or fondaparinux for a minimum of 7 days If renal impairment - LMWH or UFH

Question 32

Describe VTE prophylaxis for pregnant patients

Answer 32

LMWH started 4-8 hours post-birth/miscarriage/termination, continued for minimum of 7 days if risk of VTE outweights risk of bleeding

Question 33

Resuscitation fluids adult

Answer 33

500ml 0.9% saline in less than 15 minutes 250ml if heart/renal failure

Question 34

Maintainance fluids adult

Answer 34

25-30ml/kg/day of fluid 1mmol/kg/day sodium, potassium, chloride 50-100g/day glucose (need more if losses e.g. vomiting, diarrhoea, will need extra potassium if deplete) e.g. 25-30ml/kg/day 0.18% sodium chloride in 4% glucose with potassium added

Question 35

Which fluids should be given with a variable rate insulin infusion for diabetic patients undergoing surgery?

Answer 35

Potassium chloride with glucose and sodium chloride

Question 36

Maintainence fluids for children

Answer 36

100ml/kg for 1st 10kg 50ml/kg for next 10kg 20ml/kg for further weight Fluid of choice is usually 0.9% saline with 5% glucose, usually given with 20mmol of potassium (pre-mixed)

Question 37

Resuscitation fluids for children

Answer 37

10ml/kg 0.9% saline

Question 38

Rehydration fluids for children

Answer 38

Calculate deficit - weight x % dehydration x 10 Total requirement = maintenance + replacement of deficit + replacement of ongoing losses

Question 39

Target INR for patients taking warfarin undergoing surgery

Answer 39

Less than 1.5 - give oral vitamin K if INR 1.5 or higher Can give bridging LMWH if high risk for VTE

Question 40

List common drugs which require therapeutic monitoring

Answer 40

Antiepileptics - carbamazepine, phenobarbitol, phenytoin, sodium valproate Antibiotics - gentamicin, tobramycin, vancomycin Lithium Theophylline Clozapine

Question 41

List drugs which can cause urinary retention

Answer 41

Tricyclic antidepressants Anticholinergics Opioids NSAIDs Disopyramide

Question 42

List drugs which can cause lung fibrosis

Answer 42

Amiodarone Cytotoxics - bleomycin Immunosuppressants - methotrexate, sulfasalazine Nitrofurantoin Dopamine receptor agonists - bromocriptine, cabergoline, pergolide