Mefloquine in the geographic region visited. It is typically taken for one to two weeks before entering an area with malaria. Doxycycline and atovaquone/proguanil provide protection within one to two days and may be better tolerated. If a person becomes ill with malaria despite prophylaxis with mefloquine, the use of halofantrine and quinine for treatment may be ineffective. Mefloquine is used as a treatment for chloroquine-sensitive or resistant "Plasmodium falciparum" malaria, and is deemed a reasonable alternative for uncomplicated chloroquine-resistant "Plasmodium vivax" malaria. It is one of several drugs recommended by the United States' Centers for Disease Control and Prevention. It
Mefloquine with an increased risk of birth defects or miscarriages. The drug may be used during breastfeeding, though it appears in breast milk in low concentrations. The World Health Organization gives approval for the use of mefloquine in the second and third trimesters of pregnancy and use in the first trimester does not mandate termination of pregnancy. Mefloquine is metabolized primarily through the liver. Its elimination in persons with impaired liver function may be prolonged, resulting in higher plasma levels and an increased risk of adverse reactions. The mean elimination plasma half-life of mefloquine is between two and four weeks. Total