Mefloquine, sold under the brand name Lariam among others, is a medication used to prevent or treat malaria. When used for prevention it is typically started before potential exposure and continued for several weeks after potential exposure. It can be used to treat mild or moderate malaria but is not recommended for severe malaria. It is taken by mouth.Common side effects include vomiting, diarrhea, headaches, sleep disorders, and a rash. Serious side effects include potentially long-term mental health problems such as depression, hallucinations, and anxiety and neurological side effects such as poor balance, seizures, and ringing in the ears. It is therefore not recommended in people with a history of mental health problems or epilepsy. It appears to be safe during pregnancy and breastfeeding.Mefloquine was developed by the United States Army in the 1970s and came into use in the mid-1980s. It is on the World Health Organizations List of Essential Medicines. It is available as a generic medication. Medical uses
Mefloquine is used to both prevent and treat certain forms of malaria. Malaria prevention
Mefloquine is useful for the prevention of malaria in all areas except for those where parasites may have resistance to multiple medications, and is one of several anti-malarial medications recommended by the United States Centers for Disease Control and Prevention for this purpose. It is also recommended by the Infectious Disease Society of America for malaria prophylaxis as a first or second-line agent, depending on resistance patterns in the malaria found in the geographic region visited.
Because of the drugs very long half-life, the Centers for Disease Control originally recommended a mefloquine dosage of 250 mg every two weeks; however, this caused an unacceptably high malaria rate in the Peace Corps volunteers who participated in the approval study, so the drug regimen was switched to once a week.By 1991, Hoffman was marketing the drug on a worldwide basis.By the 1992 UNITAF, Canadian soldiers were being prescribed the drug en masse.By 1994, medical professionals were noting "severe psychiatric side effects observed during prophylaxis and treatment with mefloquine", and recommending that "the absence of contraindications and minor side effects during an initial course of mefloquine should be confirmed before another course is prescribed." Other doctors at the University Hospital of Zurich noted in a case of "a 47-year-old, previously healthy Japanese tourist" who had severe neuropsychiatric side-effects from the drug that
The neuropsychiatric side effects of the antimalarial drug mefloquine are well documented. They include anxiety, depression, hallucinations, acute psychosis, and seizures. The incidence of these side effects is 1 in 13,000 with prophylactic use and 1 in 250 with therapeutic use. The first randomized, controlled trial on a mixed population was performed in 2001. Prophylaxis with mefloquine was compared to prophylaxis with atovaquone-proguanil. Roughly 67% of participants in the mefloquine arm reported greater than or equal to one adverse event, vs 71% in the atovaquone-proguanil arm.