WASHINGTON, Oct. 4 (UPI) -- The Army has told Congress there is "sufficient evidence" to question the use of a controversial malaria drug because of mental problems, but not enough evidence to stop using it on U.S troops, according to a document obtained by United Press International.
House Military Personnel Subcommittee Chairman Rep. John McHugh, R-N.Y., wrote the Pentagon in May for a review of the military's use of the drug, called Lariam or mefloquine, out of concern that it might cause mental problems among troops.
After a review of the scientific literature, the Army believes there is enough data to question the use of Lariam -- but not enough to stop using it, according to a letter from Assistant Secretary of Defense Dr. William Winkenwerder, Jr., which was dated Sept. 13.
"In summary, sufficient evidence exists to raise the question whether the neuropsychiatric adverse events of mefloquine are frequent enough and severe enough to warrant limiting its use," according to the document.
"However, sufficient evidence does not exist to answer the question, especially in the case of military personnel."
Beginning in early June of this summer, three Fort Bragg, N.C., soldiers who took Lariam in Afghanistan returned home and allegedly killed their wives. Two then committed suicide.
Lariam's label warns of aggression, paranoia, psychosis and of reports of suicide. Lariam's manufacturer added the suicide warning to the drug label in July.
"The current issues regarding the adverse effects of mefloquine have raised concerns within the (Department of Defense) as well as within the health-related scientific community worldwide," Winkenwerder wrote. He did not refer to the Fort Bragg killings or the changes to Lariam's label.
The Army has said it would seek a "clarification" from the manufacturer, Hoffmann-La Roche, on the recent changes to the label. The Army also sent a team to Fort Bragg to look into a series of factors, including Lariam.
According to the Pentagon, side effects from Lariam have not been common enough or serious enough to stop using it and switch to an alternative drug -- and possible side effects are "greatly outweighed by the drug's effectiveness in preventing the severe consequences of malaria infections" among troops.
Lariam will continue to be an "optimal choice for health care providers faced with ensuring the protection of personnel," it said.
The Pentagon also said a review of recent research showed that the drug is highly effective at preventing malaria, but cited a recent study saying that "no one appears to know for certain whether mefloquine is well or poorly tolerated."
The Pentagon also acknowledges that getting to the bottom of the issue is complicated because most studies were performed by the military or Roche. The Army invented Lariam and licensed it to Roche.
"This fact suggests at least the possibility of either commercial or institutional bias in the reporting of results," it said.
The Centers for Disease Control and Prevention is reviewing its recommendations for drugs to prevent malaria, including Lariam. The Pentagon said it would review those new recommendations, expected early next year.
