Methemoglobinemia is caused by:: (A) Prilocaine, (B) Ropivacaine, (C) Bupivacaine, (D) Procaine
Answer is A. Ans. (A) Prilocaine(Ref: Katzung 11th/e p449)The administration of large doses (>10mg/kg) of prilocaine during regional anesthesia may lead to accumulation of the metabolite o-toluidine, an oxidizing agent capable of converting hemoglobin to methemoglobin.The treatment of methemoglobinemia involves the intravenous administration of reducing agents (eg. methylene blue or ascorbic acid), which rapidly convert methemoglobin to hemoglobin.