What started as a four-month prescription was turned into years of debilitating side effects for a former sailor who took preventative malaria pills during his deployment.

While serving a tour in East Africa in 2009, the 32-year-old was prescribed a drug called mefloquine.

A June profile published in Drug Safety Case Reports — and first reported on by the Marine Corps Times — says he began suffering mental disorders within weeks of taking the pills.

Throughout the deployment, he suffered frequent anxiety and vivid nightmares. By the time he returned home, he was experiencing dizziness, anger and a severe lack of motor skills. He told doctors that it felt like “everything in front of me is moving.”

The report says he “routinely stumbles when walking and has fallen down the stairs once. Prior to his deployment, the patient was a marathon runner but is now unable to run due to disequilibrium and vertigo.”

After a series of testing and ineffective treatment, he was diagnosed with post-traumatic stress disorder because of a firefight he had experienced while on deployment. He was subsequently prescribed a laundry list of medications that helped with anxiety but did nothing to aid his nightmares and lack of balance.

The side effects persisted, causing problems with his family and work, and he was eventually referred for evaluation at Walter Reed National Medical Center.

Because of the overlap between PTSD and mefloquine toxicity symptoms, it is difficult to distinguish what exactly was caused by the medication and what was not. Regardless, it’s been confirmed that side effects from mefloquine can persist for several years or even permanently.

Questions about the drug surfaced almost immediately after it was approved by the FDA in 1989, but it took years for the research to catch up:

“Although the original product [description] alluded to the potential for neuropsychiatric side effects, it would be another 10–15 years before the full scope of toxicity, when used for malaria prophylaxis, was demonstrated in randomized control trials,” the report says.

By 2003, the FDA began requiring anyone taking the drug to have a “patient medication guide” (the aforementioned sailor did not receive one). Around this time was the peak of the military’s use of mefloquine, with nearly 50,000 prescriptions issued by doctors in 2003 according to the Marine Corps Times. That number was down to 216 prescriptions last year.

The pervasiveness of mefloquine toxicity in service members is unknown and is not limited to those deployed to Africa. Veterans of the Iraq and Afghanistan wars were also prescribed various medication to fight malaria, including mefloquine.

However due to increasing awareness of its neurologic and psychologic side effects, the military has reduced the mefloquine to a third string option behind other preventative malaria medications.

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