Neurotoxic vestibulopathy is a common but under recognized outcome following use of the neurotoxic antimalarial drug, mefloquine (also known as Lariam). In 2013, the FDA cautioned that neurological effects from mefloquine, to include dizziness, loss of balance, or ringing in the ears, could be permanent. Other possible impacts include fatigue and cognitive problems. Mefloquine has been widely used by U.S. military personnel since its introduction in the 1980s, such as during operations in Somalia in the early 1990s, during Operations Iraqi Freedom (OIF) beginning in 2003 among personnel deployed to Iraq and Kuwait, and during Operation Enduring Freedom beginning in 2001 among personnel deployed in Afghanistan, and in related operations in Africa and Southeast Asia. As documentation of mefloquine prescribing was often poor, many military personnel will not have evidence of the drug in their medical record. A history of exposure to mefloquine should be assumed if the military service member reports taking a once-weekly tablet that is white slightly smaller than dime-sized, for prevention of malaria.