Pharmacokinetics of mefloquine when given as a single and two divided-dose regimens

The pharmacokinetics of mefloquine at 1250 mg, when given as a single oral dose or as 2 divided doses of 750 and 500 mg at 6-h intervals, was investigated in 18 Thai male patients with acute uncomplicated P. falciparum malaria. The pharmacokinetics of each of these two treatment regimens, expressed as the mean followed by the S.D. in brackets, were found to be similar. Maximum concentrations of 2302 (750) and 2399 (418) ng/ml were achieved at 15.9 (4.5) and 17.1 (3.1) h after a single and a divided-dose regimen respectively. Other parameters were also comparable between the 2 regimens of mefloquine [AUC: 21.78 (5.99) vs 20.7 (604) micrograms.day/ml; Vdz/f: 23.7 (3.4) vs 24.9 (3.7) L/kg; CL/f: 0.899 (0.23) vs 1.02 (0.51) ml/min/kg; t1/2z: 12.5 (3.2) vs 11.4 (2.1) days; MRT: 16.2 (2.2) vs 16.8 (3.1) days]. In areas where P. falciparum is highly resistant to mefloquine, the elevated dose of 1250 mg may prove beneficial when given as the 2 divided doses at a 6-h interval.