Which local anesthetic is most commonly noted for methemoglobinemia risk and is considered low-toxic?

Which local anesthetic is most commonly noted for methemoglobinemia risk and is considered low-toxic?

• A. Prilocaine
• B. Lidocaine
• C. Mepivacaine
• D. Bupivacaine

Answer: (A)

Prilocaine has a distinctive safety profile: it is generally considered relatively low in systemic toxicity, but its metabolism yields o-toluidine, a compound that can oxidize hemoglobin to methemoglobin. This creates a methemoglobinemia risk that can become significant with higher doses or in susceptible patients (such as infants). The other commonly used local anesthetics can cause CNS or cardiovascular toxicity at high levels, but they do not carry methemoglobinemia risk to the same notable extent. So, among these options, prilocaine is the one most noted for methemoglobinemia risk while still being viewed as low-toxic overall.

Prilocaine has a distinctive safety profile: it is generally considered relatively low in systemic toxicity, but its metabolism yields o-toluidine, a compound that can oxidize hemoglobin to methemoglobin. This creates a methemoglobinemia risk that can become significant with higher doses or in susceptible patients (such as infants). The other commonly used local anesthetics can cause CNS or cardiovascular toxicity at high levels, but they do not carry methemoglobinemia risk to the same notable extent. So, among these options, prilocaine is the one most noted for methemoglobinemia risk while still being viewed as low-toxic overall.