Federal drug officials have issued a strong new warning about a controversial anti-malaria medication once routinely given to U.S. troops, some of whom say it damaged them permanently.
The Food and Drug Administration ordered manufacturers of mefloquine hydrochloride to give the medicine a black box label, the agency’s strongest warning, reserved for drugs with significant risks of serious side effects. The FDA said some neurological and psychiatric side effects can last for months or years after a patient stops taking the drug.
The medication was approved by the FDA in 1989 under the brand name Larium and quickly became a leading drug for preventing and treating malaria – among travelers and the military.
But the drug has long carried warnings tying it to dizziness, seizures, insomnia, anxiety, depression and strange dreams. One clinical trial found that 29 percent of travelers who took mefloquine experienced at least one of those side effects. There is also evidence suggesting a link to violent behavior, including suicide.
Amid growing concerns, the drug fell out of favor over the last decade. Roche, its original manufacturer, stopped selling Larium in the U.S. in 2008. The generic versions still on the market accounted for 226,000 of the 5.4 million U.S. prescriptions for anti-malaria drugs last year, according to IMS Health, which track drug trends.
The Pentagon, which used the drug widely in Somalia and during the early years of the wars in Iraq and Afghanistan, offered little explanation when it began scaling back its reliance on mefloquine and eventually recommended that the drug be used only as a third choice.
The FDA strengthened its warning this week based on a new review of medical literature and reports of patients suffering from dizziness, loss of balance, tinnitus and vertigo, according to a statement from the agency.
The symptoms often started after the first dose or two but continued for months or years. In some cases, the damage was deemed permanent. Usually, the neurological symptoms were accompanied by psychiatric ones, including anxiety, confusion, paranoia and depression, which were also long-lasting.
The controversy surrounding mefloquine has led to speculation by veterans and others that it may have played a role in the March 11, 2012, killing of 16 Afghan civilians by Army Staff Sgt. Robert Bales.
His lawyer, John Henry Browne, said the new FDA warning of long-term side effects could play a role in sentencing proceedings, which are scheduled to begin Aug. 19.
Bales had taken mefloquine while serving in Iraq, but it remains unclear whether he was taking the drug in Afghanistan, Browne said.
He said he is requesting the reports that served as the basis of the FDA warning.