Which of the following local anaesthetic causes methemoglobinemia?
Prilocaine similar to that of lidocaine. The primary differences are that it causes little vasodilation and thus can be used without a vasoconstrictor, and its increased volume of distribution reduces its CNS toxicity, making it suitable for intravenous regional blocks. The drug is unique among the local anesthetics in its propensity to cause methemoglobinemia. This effect is a consequence of the metabolism of the aromatic ring to o-toluidine. Development of methemoglobinemia is dependent on the total dose administered, usually appearing after a dose of 8 mg/kg. Ref: Catterall W.A., Mackie K. (2011). Chapter 20. Local Anesthetics. In L.L. Brunton, B.A. Chabner, B.C. Knollmann (Eds), Goodman & Gilman's The Pharmacological Basis of Therapeutics, 12e.
Procaine
Prilocaine
Etidocaine
Ropivacaine