Mefloquine one. Plasma concentrations of the (–)-enantiomer are significantly higher than those for the (+)-enantiomer, and the pharmacokinetics between the two enantiomers are significantly different. The (+)-enantiomer has a shorter half-life than the (–)-enantiomer. According to some research, the (+)-enantiomer is more effective in treating malaria, and the (–)-enantiomer specifically binds to adenosine receptors in the central nervous system, which may explain some of its psychotropic effects. Mefloquine was formulated at Walter Reed Army Institute of Research (WRAIR) in the 1970s shortly after the end of the Vietnam war. Mefloquine was number 142,490 of a total of 250,000 antimalarial compounds screened
Mefloquine clearance is through the liver, and the primary means of excretion is through the bile and feces, as opposed to only 4% to 9% excreted through the urine. During long-term use, the plasma half-life remains unchanged. Liver function tests should be performed during long-term administration of mefloquine. Alcohol use should be avoided during treatment with mefloquine. Mefloquine is a chiral molecule with two asymmetric carbon centres, which means it has four different stereoisomers. The drug is currently manufactured and sold as a racemate of the ("R","S")- and ("S","R")-enantiomers by Hoffman-LaRoche, a Swiss pharmaceutical company. Essentially, it is two drugs in