Etomidate Concentration — FRCA Primary MCQ
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Correct answer: B — 2 mg/mL
Explanation lettering: E = shown as A · C = shown as B · A = shown as C · B = shown as E
The correct answer is C, 2 mg/mL. A 0.2% w/v solution contains 0.2 g of drug in 100 mL of solution. This is 200 mg in 100 mL, so the concentration is 200 ÷ 100 = 2 mg/mL. The UK SmPC likewise states that each millilitre of Hypnomidate contains 2 mg of etomidate. Option B incorrectly treats the percentage value as though it were already expressed in mg/mL. Options A and D result from misplaced decimal points or incorrect conversion between grams and milligrams. Option E is one hundredfold too low. For percentage w/v solutions, multiplying the percentage value by 10 gives the concentration in mg/mL.
Reference: Piramal Critical Care Limited. Hypnomidate 2 mg/ml Injection, Summary of Product Characteristics, section 2: Qualitative and quantitative composition. Revised 2024. https://www.medicines.org.uk/emc/product/9777/smpc