The Food and Drug Administration (FDA) has revised the labeling of the antimalarial drug mefloquine hydrochloride to strengthen its warnings about the risks of neuropsychiatric and neurologic reactions. These concerns aren't new, but by revising the label the FDA has placed more emphasis on these possible effects in order to alert health care providers. The label had previously warned against using mefloquine in patients with major psychiatric disorders or a history of seizures. A new boxed warning highlights mefloquine's ability to produce adverse psychiatric effects such as anxiety, paranoia, depression, and hallucinations. Suicidal ideation has also been reported.

Also listed among the boxed warnings is a notation on neurologic vestibular problems, which include dizziness, loss of balance, and ringing in the ears. The neurologic symptoms can appear at any time during drug use (even after only one or two doses) and can last for months or years after the drug is discontinued. In some cases the changes are permanent. Patients who exhibit vestibular problems usually have concomitant psychiatric symptoms.

A revised medication guide informs patients that the neurologic adverse effects can persist or even be permanent. Nurses should assess patients closely for adverse vestibular and psychiatric effects; these can be especially difficult to identify in children. Nurses should also instruct patients to be alert for symptoms and report them at once. If a patient develops any of these symptoms, the drug should be stopped and an alternative antimalarial medication used.

The revised FDA prescribing information is available at http://1.usa.gov/162hmO5.