Antimalarial medication multi-drug resistant "P. falciparum". It is a very potent blood schizonticide with a long half-life. It is thought to act by forming toxic heme complexes that damage parasitic food vacuoles. Mefloquine is effective in prophylaxis and for acute therapy. It is now used solely for the prevention of resistant strains of "P. falciparum" (usually combined with Artesunate) despite being effective against "P. vivax", "P. ovale" and "P. marlariae". Chloroquine/proguanil or sulfa drug-pyrimethamine combinations should be used in all other plasmodia infections. The major commercial manufacturer of mefloquine-based malaria treatment is Roche Pharmaceuticals, which markets the drug under the trade name
Mefloquine of the users reported severe events requiring medical attention, vs 1.2% in the atovaquone-proguanil arm. The brand name drug, Lariam, is manufactured by the Swiss company Hoffmann–La Roche. In August 2009, Roche stopped marketing Lariam in the United States. In June 2010, the first case report appeared of a progressive multifocal leukoencephalopathy being successfully treated with mefloquine. Mefloquine can also act against the JC virus. Administration of mefloquine seemed to eliminate the virus from the patient's body and prevented further neurological deterioration. WRAIR has published several papers outlining ongoing efforts at that institution to make mefloquine safer by producing a