MSRA MSRA Pharmacology and Prescribing

Question 1

A patient on warfarin is started on amoxicillin for a chest infection. What is the most likely effect on their INR?

Accepted Answer

Increase in INR

Answer

Antibiotics reduce gut flora that produce Vitamin K, decreasing its availability and potentiating warfarin's anticoagulant effect, thereby raising the INR.

Question 2

Which of the following is a contraindication to metformin use?

Accepted Answer

eGFR < 30 mL/min/1.73m²

Answer

Metformin is contraindicated in severe renal impairment (eGFR < 30) because impaired excretion leads to accumulation and risk of potentially fatal lactic acidosis.

Question 3

A patient presents with an acute gout attack. Which intervention should be avoided during the acute phase?

Accepted Answer

Initiating allopurinol

Answer

Starting allopurinol during an acute gout attack can mobilise urate crystals and prolong or worsen the attack; it should be initiated 2–4 weeks after resolution.

Question 4

A patient taking an ACE inhibitor develops a persistent dry cough. What is the most appropriate management?

Accepted Answer

Switch to an angiotensin receptor blocker (ARB)

Answer

ACE inhibitor cough is caused by bradykinin accumulation; switching to an ARB avoids this mechanism while maintaining renin-angiotensin system blockade.

Question 5

A patient on lithium develops coarse tremor, ataxia, and confusion. What is the most likely diagnosis?

Accepted Answer

Lithium toxicity

Answer

Lithium toxicity classically presents with coarse tremor (distinct from the fine tremor at therapeutic levels), ataxia, and confusion, progressing to seizures and coma in severe cases.

MSRA Exam (Multi-Specialty Recruitment Assessment) Practice Test

MSRA Exam (Multi-Specialty Recruitment Assessment) Practice Test

MSRA MSRA Pharmacology and Prescribing