NZREX Pharmacology & Prescribing 2

Question 1

A patient on lithium for bipolar disorder presents with coarse tremor, confusion, and vomiting. His serum lithium level is 2.3 mmol/L. What is the most appropriate immediate management?

Accepted Answer

Cease lithium immediately and consider haemodialysis

Answer

Halve the lithium dose and recheck levels in 24 hours

Answer

Add an antiemetic and continue lithium at the same dose

Answer

Switch to valproate and discharge home

Question 2

A patient with rheumatoid arthritis is commenced on weekly oral methotrexate. Which supplement must be co-prescribed to reduce the risk of mucositis and haematological side effects?

Accepted Answer

Folic acid

Answer

Vitamin B12

Answer

Vitamin D

Answer

Iron

Question 3

Which antibiotic class is generally contraindicated in children under 12 years due to the risk of arthropathy and potential damage to developing cartilage?

Accepted Answer

Fluoroquinolones (e.g., ciprofloxacin)

Answer

Penicillins (e.g., amoxicillin)

Answer

Macrolides (e.g., azithromycin)

Answer

Cephalosporins (e.g., cefalexin)

Question 4

A patient taking ramipril (ACE inhibitor) is commenced on spironolactone (a potassium-sparing diuretic). Which electrolyte imbalance must be closely monitored?

Accepted Answer

Hyperkalaemia

Answer

Hyponatraemia

Answer

Hypocalcaemia

Answer

Hypomagnesaemia

Question 5

A patient with type 2 diabetes has a new eGFR of 25 mL/min/1.73m². What change should be made to their metformin therapy?

Accepted Answer

Cease metformin as it is contraindicated at this eGFR

Answer

Continue metformin at the same dose with routine monitoring

Answer

Reduce the metformin dose by 50% and monitor closely

Answer

Switch to intravenous metformin for reliability

Question 6

A patient stabilised on warfarin is commenced on amiodarone for persistent atrial fibrillation. What effect does amiodarone have on warfarin anticoagulation?

Accepted Answer

Increases warfarin effect by inhibiting CYP2C9

Answer

Reduces warfarin effect by inducing CYP2C9

Answer

Has no clinically significant effect on warfarin metabolism

Answer

Reduces warfarin absorption from the gastrointestinal tract

Question 7

A patient at 10 weeks gestation develops an uncomplicated urinary tract infection. Which antibiotic should be AVOIDED in the first trimester primarily due to its folate antagonism?

Accepted Answer

Trimethoprim

Answer

Cefalexin

Answer

Nitrofurantoin

Answer

Amoxicillin