Epinephrine Mechanism in LA — NDEB AFK 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: D — Stimulating alpha-adrenergic receptors causing local vasoconstriction
Epinephrine in local anaesthetic acts primarily through α1-adrenergic receptor stimulation, causing vasoconstriction of arterioles at the injection site. This reduces blood flow, slowing systemic absorption of the anaesthetic, thereby prolonging duration of action, increasing depth of anaesthesia, reducing bleeding, and decreasing the risk of systemic toxicity. The standard dental concentration is 1:100,000 (10 μg/mL) or 1:200,000 (5 μg/mL).
Reference: Malamed – Handbook of Local Anesthesia, 7th ed., 2020