MSRA Pharmacology and Prescribing Flashcards

A patient prescribed gentamicin requires monitoring. Which parameters are most important to check?

Answer: Renal function and drug trough/peak levels

Gentamicin is an aminoglycoside antibiotic that is nephrotoxic and ototoxic; monitoring renal function and serum drug levels is essential to prevent toxicity.

A patient on simvastatin is prescribed clarithromycin. What is the most significant clinical risk of this interaction?

Answer: Increased risk of myopathy and rhabdomyolysis

Clarithromycin inhibits CYP3A4, the enzyme responsible for simvastatin metabolism, causing statin levels to rise dramatically and increasing the risk of myopathy and rhabdomyolysis.

A patient with a history of anaphylaxis to penicillin requires treatment for confirmed MSSA bacteraemia. Which antibiotic is most appropriate?

Answer: Vancomycin

Patients with penicillin anaphylaxis carry a small but clinically significant cross-reactivity risk with cephalosporins; vancomycin is the safest non-beta-lactam alternative for serious staphylococcal infections.

Which of the following medications routinely requires therapeutic drug level monitoring in clinical practice?

Answer: Phenytoin

Phenytoin has a narrow therapeutic index and exhibits non-linear (zero-order) pharmacokinetics at higher doses, making plasma level monitoring essential to ensure efficacy and avoid toxicity.

A patient on long-term prednisolone is scheduled for major surgery. What is the most critical perioperative consideration?

Answer: Administer hydrocortisone cover for adrenal insufficiency

Long-term corticosteroid use suppresses the hypothalamic-pituitary-adrenal axis; IV hydrocortisone cover is required perioperatively to prevent an Addisonian crisis during the physiological stress of surgery.

Which anticoagulant is the treatment of choice for a pregnant patient diagnosed with deep vein thrombosis?

Answer: Low molecular weight heparin (LMWH)

LMWH (e.g., enoxaparin) does not cross the placenta and is the anticoagulant of choice in pregnancy; warfarin is teratogenic and direct oral anticoagulants are contraindicated in pregnancy.

A patient newly started on sodium valproate requires monitoring. Which investigations are most important?

Answer: Liver function tests and full blood count

Sodium valproate can cause hepatotoxicity (especially in young children) and thrombocytopenia, so liver function tests and full blood count must be monitored regularly.