Whole blood concentrations of mefloquine enantiomers in healthy Thai volunteers.

We studied the pharmacokinetics of the enantiomers of mefloquine in whole blood in healthy Thai volunteers after administration of a single oral dose of 750 mg of the racemic mixture. Mefloquine pharmacokinetics were stereoselective. The peak concentrations and areas under the curve of the (-) enantiomer were significantly higher than those of its antipode (0.79 versus 0.46 microgram.ml-1 and 402 versus 94 micrograms.h.ml-1). The half-lives of (-)MQ were significantly longer than those of (+)MQ (531 versus 206 h). No stereoselectivity was observed for tmax values.