Prilocaine causes methemoglobinemia, hence it is largely limited to dentistry. 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. Methemoglobinemia is more common in neonates due to decreased resistance of fetal hemoglobin to oxidant stresses and the immaturity of enzymes in the neonate that conve methemoglobin back to the ferrous state. 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.