Alfentanil Drawing Up Calculation — SCE Palliative Medicine MCQ

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EasySyringe Driver & Drug CompatibilityAlfentanil Drawing Up CalculationSCE Palliative Medicine

A community nurse needs to draw up a CSCI containing alfentanil 3 mg/24 hours for a dying patient with renal failure. The alfentanil injection available is 500 micrograms/mL (1 mL ampoules). How many ampoules are needed?

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Reveal the answer and explanation

Correct answer: D — 6 ampoules

Explanation lettering: D = shown as A · E = shown as B · A = shown as D · B = shown as E

The correct answer is A (6 ampoules). This is a straightforward pharmaceutical calculation: 3 mg = 3000 mcg, and dividing by the strength per ampoule (500 mcg) gives 6. Alfentanil 500 mcg/mL in 1 mL ampoules is the standard UK formulation available for CSCI in palliative care and is particularly appropriate for this patient with renal failure, as its dose does not require reduction in chronic kidney disease (unlike other opioids). Option B (3 ampoules) results from incorrectly dividing 3 mg by 1 instead of converting units. Option C (30 ampoules) arises from multiplying rather than dividing. Options D and E represent gross under- or miscalculation. For Higher Specialist Trainees, rapid, accurate pharmaceutical calculations are essential before drawing up potent opioids in CSCI preparations.

Reference: Right Decisions Palliative Care (NHS Scotland) Alfentanil Guidance; Alfentanil 500 micrograms/ml SmPC (medicines.org.uk); Scottish Palliative Care Guidelines: Choosing and Changing Opioids; 2026/current, https://www.rightdecisions.scot.nhs.uk/shared-content/palliative-care/alfentanil/