LA Without Vasoconstrictor — MFDS Part 1 MCQ
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Correct answer: C — 3% mepivacaine hydrochloride solution for dental injection
Explanation lettering: B = shown as A · C = shown as B · A = shown as C · E = shown as D · D = shown as E
The correct answer is A. The 3% mepivacaine dental cartridge formulation is supplied without an added vasoconstrictor. By contrast, options B and C explicitly contain adrenaline, as does the 2% mepivacaine formulation in option D. Option E is also incorrect because felypressin is a vasoconstrictor, although it is not a catecholamine and may be used when adrenaline is unsuitable. Vasoconstrictors reduce local blood flow, slow systemic absorption and generally prolong local anaesthetic action. The original reference to 3% prilocaine as “Citanest Plain” was removed because current UK dental cartridge information identifies 3% prilocaine as the felypressin-containing formulation.
Reference: NHS Specialist Pharmacy Service. Managing reactions to dental local anaesthetic injections: Contents of dental LA cartridges. 2024. https://sps.nhs.uk/articles/managing-reactions-to-dental-local-anaesthetic-injections/