Simultaneous estimation of serum concentrations of dapsone, monoacetyldapsone, and pyrimethamine in Chinese men on maloprim for malaria prophylaxis using reversed-phase high performance liquid chromatography.

A reversed-phase high performance liquid chromatography method was developed to simultaneously estimate serum concentrations of dapsone (DDS), monoacetyldapsone (MADDS), and pyrimethamine (PYR) in 34 young adult Chinese men after they had taken the sixth weekly dose of Maloprim for malaria prophylaxis. Serum concentrations of DDS, MADDS, and PYR after 24 h were (mean +/- SEM) 374 +/- 31.3, 310 +/- 30.4, and 121 +/- 7.9 ng/ml, respectively. The 72-h serum concentrations of DDS, MADDS, and PYR were (mean +/- SEM) 134 +/- 21.6, 115 +/- 17.9, and 80 +/- 7.2 ng/ml, respectively. Serum concentrations of DDS and MADDS in many subjects after 120 h were less than 20 ng/ml, while mean +/- SEM concentration of PYR was 53 +/- 5.6 ng/ml. Acetylator phenotyping of the subjects showed that there were 31 (91%) fast acetylators, three (9%) intermediate acetylators, and no slow acetylators.