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 events, about 11-17% of travelers are incapacitated to some degree. Mefloquine may cause abnormalities with heart rhythms that are visible on electrocardiograms. Combining mefloquine with other drugs that cause similar effects, such as quinine or quinidine, can increase these effects. Combining mefloquine with halofantrine can cause significant increases in QTc intervals. Mefloquine is contraindicated in those with a previous history of seizures or a recent history of psychiatric disorders. Women should not become pregnant and should use effective birth control while taking mefloquine. A retrospective analysis of outcomes in more than 2,500 women found no evidence that mefloquine was associated