Myasthenia Gravis — ORE Part 1 MCQ

Correct answer: D — Aminoglycosides

Aminoglycosides are the best answer. Gentamicin, an aminoglycoside, is contraindicated in myasthenia gravis in the UK SmPC because aminoglycosides can impair neuromuscular transmission and may precipitate clinically important weakness or respiratory compromise. This makes the class inappropriate where an alternative is available. Penicillins are not class-contraindicated; indeed, most are regarded as relatively safer choices, although ampicillin has occasionally been associated with worsening and treatment should be individualised. Cephalosporins and metronidazole do not share the characteristic aminoglycoside neuromuscular-blocking risk. Tetracyclines may warrant caution in myasthenia gravis, but they are not the unequivocal contraindicated class represented here. The key discriminating feature is the established neuromuscular-blocking effect of aminoglycosides.

Reference: electronic Medicines Compendium. Gentamicin 10 mg/ml Solution for Injection or Infusion: Summary of Product Characteristics, section 4.3 Contraindications, 2023. https://www.medicines.org.uk/emc/product/2407/smpc