Gender-specific Distribution of Mefloquine in the Blood of Healthy Volunteers Following the Administration of Therapeutic Doses

Abstract

The distribution of the antimalarial drug mefloquine (MQ) following the administration
of standard therapeutic doses (1,250 mg mefloquine in split dose) to 22 healthy Caucasian
volunteers was assessed in whole blood, serum, plasma, RBCs, WBCs, and platelets using high
performance liquid chromatography. Plasma MQ levels after 14, 48, and 168 hours were
considerably higher in female subjects than in males, concordant with a significantly higher
frequency, duration, and severity of adverse reactions. However, mean drug concentrations of
RBCs tended to be higher in male volunteers. The concentrations in other blood components
were similar in both genders. No correlation was seen between MQ concentrations in plasma
and RBCs. Since the observations relate to healthy individuals, they do not take into account t
selective uptake of MQ by Plasmodium-infected RBCs as in the case of therapeutic drug use.
Although plasma MQ levels in female healthy volunteers are considerably higher and the
concentrations of the RBC are initially lower as compared to males they do not seem to justify
an adjustment of treatment guidelines for MQ in female Caucasian individuals.