Clinical Pharmacology and Toxicology

Question 1

Drugs that can be cleared by haemodialysis
“BLAST”

Answer 1

• Barbiturate
• Lithium
• Alcohol (includes methanol, ethylene glycol)
• Salicylates
• Theophylline (charcoal hemoperfusion is preferable)

Question 2

Fluoroquinolones MOA - Bactericidal

Answer 2

• Inhibits DNA synthesis by inhibiting topoisomerase II (DNA gyrase) and topoisomerase IV

Question 3

Drugs a/w increased risk of developing Hepatotoxicity in paracetamol overdose

Answer 3

• Patients taking liver enzyme-inducing drugs (rifampicin, phenytoin, carbamazepine, St John’s Wort)
• Patients with a history of chronic alcohol excess
  Malnourished patients (e.g. anorexia nervosa) or - patients who have not eaten for a few days, due to depletion of glutathione.

Question 4

Drugs causing photosensitivity

Answer 4

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

Question 5

Criteria for Liver transplantation in paracetamol overdose

Answer 5

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 6

Drugs that causes Agranulocytosis

Answer 6

-Antithyroid drugs - carbimazole, propylthiouracil
-Antipsychotics - atypical antipsychotics (CLOZAPINE)
-Antiepileptics - carbamazepine
-Antibiotics - penicillin, chloramphenicol, co-trimoxazole
-Antidepressant - mirtazapine
-Cytotoxic drugs - methotrexate

Question 7

Allele Associated with SCAR - Severe Cutaneous Adverse Reaction

Answer 7

HLA-B*5801

Question 8

Inducers of the P450 system include

Answer 8

-antiepileptics: phenytoin, carbamazepine
-barbiturates: phenobarbitone
-rifampicin
-St John’s Wort
-chronic alcohol intake
-griseofulvin
-smoking (affects CYP1A2, reason why smokers require more aminophylline)

Question 9

Inhibitors of the P450 system include

Answer 9

-antibiotics: ciprofloxacin, erythromycin
-isoniazid
-cimetidine,omeprazole
-amiodarone
-allopurinol
-imidazoles: ketoconazole, fluconazole
-SSRIs: fluoxetine, sertraline
-ritonavir
-sodium valproate
-acute alcohol intake
-quinupristin

Question 10

Drug induced Urinary retention

Answer 10

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

Question 11

Drugs that can precipitate Acute Intermittent Porphyria attacks

Answer 11

• barbiturates
• halothane
• benzodiazepines
• alcohol
• oral contraceptive pill
• sulphonamides

Question 12

Indications of BOTOX injections

Answer 12

• blepharospasm
• hemifacial spasm
• focal spasticity including cerebral palsy patients, - hand and wrist disability associated with stroke
• spasmodic torticollis
• severe hyperhidrosis of the axillae
• achalasia

Question 13

Drugs that can cause Impaired Glucose Tolerance

Answer 13

• thiazides, furosemide (less common)
• steroids
• tacrolimus, ciclosporin
• interferon-alpha
• nicotinic acid
• antipsychotics