Which local anesthetic is known to be potentially harmful in patients with methemoglobinemia?

Prilocaine is known to be potentially harmful in patients with methemoglobinemia because it has a unique metabolic pathway that can lead to the formation of methemoglobin when administered in excessive doses. Methemoglobinemia is a condition in which the iron in hemoglobin is oxidized to the ferric state, rendering it incapable of carrying oxygen effectively. Prilocaine’s metabolite, ortho-toluidine, can induce this condition, especially in susceptible individuals.

This adverse effect is particularly significant when higher doses of prilocaine are used, so caution is necessary when selecting anesthetic agents for patients with known methemoglobinemia or those at risk. While lidocaine, bupivacaine, and mepivacaine have their own safety profiles and potential side effects, they do not carry the same risk of causing methemoglobinemia as prilocaine does. Thus, understanding the pharmacological effects and metabolic processes associated with different local anesthetics is crucial for patient safety in dental procedures.