Anti-malaria drug mefloquine causing hallucinations to U.S. war veterans

Marines Rifle salute - U.S. Marine Corps, Photo by Cpl. Caitlin Brink/Released

The anti-malaria drug mefloquine (known with the commercial name Lariam) has been used for decades to protect U.S. troops serving in high-risk zones. Malaria is an infectious disease caused by the P. falciparum parasite, and it’s transmitted by mosquito bites. Back in the ’80s, the Army’s malaria drug discovery program developed a new medicine to fight this disease which was later approved for use in 1989. Mefloquine can treat or prevent malaria if taken two weeks before exposure and continued for four weeks thereafter to achieve full prophylaxis. All the soldiers who served in regions where malaria could be endemic such as Iraq, Somalia, and Afghanistan, received this drug to avoid widespread epidemics to occur within the military ranks. Although the side effects of mefloquine should be minor in most instances, and include just dizziness, nausea or bad dreams, newer studies showed that the anti-malaria medication’s adverse reaction may be much more threatening.

In 2013, CBS News reported the history of Jimmy Corrigan, a Navy soldier who suffered a brain injury after being prescribed the medication. The war veteran attempted suicide twice after suffering from a severe depression and a hallucinatory altered state of consciousness right after taking the first dose. Doctors who studied his case concluded that mefloquine’s toxicity may cause mental illness such as Post-Traumatic Stress Disorder (PTSD) in predisposing service members. However, since side effects such as hallucinations and vivid dreams were often underreported, the actual dangerousness of this medication may have been significantly underestimated. Former Army physician Dr. Remington Nevin even suggested that there’s an ongoing hidden epidemic of psychiatric injuries. As proven by the evidence reported in a case study published in the journal Drug Safety, the harmful effects of the drug’s brain toxicity can last years after a person stops taking it or even be permanent.

The U.S. Food and Drug Administration (FDA) later added a black box warning to the medicine’s label, indicating any psychiatric symptoms as a potential red flag. The Pentagon reacted by changing the way mefloquine is prescribed with two directives in 2009 and 2013. The number of prescriptions dropped steadily from the almost 50,000 in 2003 to just 216 in 2015. However, the Department of Defense never fully banned the drug, leaving it as a third choice. So far, the only branch of the military who banned all future prescriptions of mefloquine is the Army Special Forces Command.


Article written by Dr. Claudio Butticè, Pharm.D.


  1. Livezey, J., Oliver, T. & Cantilena, L. Prolonged Neuropsychiatric Symptoms in a Military Service Member Exposed to Mefloquine. Drug Saf – Case Rep (2016) 3: 7. doi:10.1007/s40800-016-0030-z
  2. U.S. Department of Veteran Affairs. Public Health – Mefloquine (Lariam®). (Accessed September 2016)
  3. Wyatt Andrews, Sarah Fitzpatrick. Some U.S. troops haunted by anti-malaria drug’s drastic side effects. CBS News, December 23, 2013
  4. Patricia Kime. Malaria drug causes brain damage that mimics PTSD: case study. Military Times, August 11, 2016.