Which local anesthetic is known to cause methemoglobinemia?

Prilocaine is the local anesthetic that is specifically recognized for its potential to cause methemoglobinemia. This condition occurs when iron in hemoglobin is oxidized, resulting in the formation of methemoglobin, which cannot effectively carry oxygen. Prilocaine can lead to this side effect due to its metabolite, o-toluene sulfonamide, which has the capacity to oxidize hemoglobin.

In clinical scenarios, this complication is particularly concerning in patients with underlying health conditions, such as those with a deficiency of the enzyme cytochrome b5 reductase, which normally helps convert methemoglobin back to its functional form. Consequently, the use of prilocaine in higher doses or in patients who might be predisposed can increase the risk of methemoglobinemia, leading to symptoms like cyanosis, fatigue, and potential respiratory distress.

The other local anesthetics mentioned do not typically cause methemoglobinemia, making prilocaine distinct in this regard. Understanding the specific side effects and risks associated with different local anesthetics is crucial for safe practice in oral and maxillofacial surgery and other dental procedures.