FDA warns mefloquine may cause psychiatric, nerve adverse effects

The FDA has issued a black box warning to the labeling of the antimalarial drug mefloquine hydrochloride, indicating that the drug has been associated with neurologic and psychiatric adverse effects.

The Medication Guide with each mefloquine prescription has been updated with the warning, along with the possibility that the adverse effects may persist or become permanent.

"Neurologic side effects can occur at any time during drug use, and can last for months to years after the drug is stopped or can be permanent," according to an FDA drug safety communication. "Patients, caregivers, and health care professionals should watch for these side effects. When using the drug to prevent malaria, if a patient develops neurologic or psychiatric symptoms, mefloquine should be stopped, and an alternate medicine should be used."

Many clinicians have already recognized the risks associated with mefloquine use.

The FDA advised that travelers to developing countries should take drugs to prevent or reduce the risk for malaria, but that those drugs may carry risks. The agency said it will continue to evaluate the safety of mefloquine.