Mefloquine is not recommended for severe malaria infections, particularly infections from "P. falciparum", which should be treated with intravenous antimalarials. Mefloquine does not eliminate parasites in the liver phase of the disease, and people with "P. vivax" malaria should be treated with a second drug that is effective for the liver phase, such as primaquine. Mefloquine is widely used for the treatment of malaria in pregnancy. Limited data suggests that it is safe for this purpose. Resistance to mefloquine is now common around the west border in Cambodia and other parts of Southeast Asia. The mechanism of resistance is by increase
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