IE Prophylaxis Dose — MFDS Part 1 MCQ

Instant feedback + full explanation. One question, done properly.

ModeratePharmacologyIE Prophylaxis DoseMFDS Part 1

An adult with no penicillin allergy has been assessed as requiring oral antibiotic prophylaxis against infective endocarditis before an at-risk dental procedure. Which of the following is an acceptable amoxicillin regimen under current SDCEP advice?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: A — 3 g as a single oral dose one hour before the procedure

Explanation lettering: D = shown as C · E = shown as D · C = shown as E

A is correct. Current SDCEP implementation advice (second edition, implementing NICE CG64) recommends a single pre-procedural oral dose of amoxicillin taken 30–60 minutes before the dental procedure in adults without penicillin allergy: either 3 g as an oral sachet (the historical UK regimen) or 2 g as four 500 mg capsules. Both are effective, with the choice based on patient and clinician preference, availability and cost-effectiveness; 3 g one hour beforehand is therefore a valid regimen. Options B and D are multi-day treatment courses, not single-dose prophylaxis, and would encourage unnecessary antimicrobial exposure. Option C is underdosed and given too late to achieve adequate serum levels at the time of bacteraemia. Option E is underdosed and outside the recommended 30–60 minute window. Remember prophylaxis is not routine: it is reserved for selected high-risk patients undergoing invasive procedures after shared decision-making, often with cardiology input.

Reference: Scottish Dental Clinical Effectiveness Programme. Antibiotic Prophylaxis Against Infective Endocarditis: Implementation Advice, 2nd edition — Oral antibiotic prophylaxis regimens. 2026. https://www.antibioticprophylaxis.sdcep.org.uk/implementation-advice/prescribing-advice/oral-antibiotic-prophylaxis-regimens/