Hyaluronidase with LA — MFDS Part 1 MCQ
Instant feedback + full explanation. One question, done properly.
Educational content. Not a substitute for clinical judgement or local policy.
Reveal the answer and explanation
Correct answer: E — Temporarily depolymerise hyaluronic acid in connective tissue, increasing tissue permeation
Explanation lettering: C = shown as A · D = shown as B · E = shown as C · B = shown as D · A = shown as E
A is correct. Hyaluronidase temporarily and reversibly depolymerises hyaluronic acid within the intercellular matrix of connective tissue. This reduces the tissue barrier to movement of injected fluid and enhances the permeation and spread of the local anaesthetic. It does not prolong anaesthesia by inhibiting vascular uptake; that is the role of a vasoconstrictor. Hyaluronidase neither blocks neuronal sodium channels itself nor stimulates alpha-1 adrenoceptors. It is not added as an antioxidant preservative and does not prevent allergy through H1-receptor antagonism. Indeed, hypersensitivity, including rare anaphylaxis, is a recognised adverse effect.
Reference: Wockhardt UK Ltd. Hyalase 1500 I.U. Powder for Solution for Injection/Infusion, Summary of Product Characteristics, sections 4.1 and 5.1. 2015. https://www.medicines.org.uk/emc/product/1505/smpc