Chloroquine-Chlorpheniramine Interaction In Human Malaria

Abstract

The purpose of this study was to examine the effect of chloroquine-chlorpheniramine (CQ-CP) combination therapy on the efficacy and disposition of chloroquine (CQ) in acute uncomplicated malaria. A 3-day standard treatment with 25 mg CQ base per kilogram body weight alone or in combination with chlorpheniramine (CP) was orally administered to 17 semi-immune Nigerian children with Plasmodium falciparum parasitemia, attending the Massey Street Children's Hospital, Lagos, Nigeria. Parasitemia was determined on thick blood films stained with Giemsa, and treatment failures were established following the WHO classification for CQ resistance. Whole blood CQ concentrations were monitored at pre-determined intervals during the 28 days of follow-up using blood dried on filter-paper. Treatment with CQ-CP combination resulted in a shorter parasite clearance time (2.0 ± 0.5 d) & a higher cure rate (87.5%) compared to treatment with CQ alone (3.5 ± 0.5 d; 66.7%). CQ pharmacokinetic parameters: maximum drug concentration (Cmax) and the area under the first-moment drug-concentration-time curve (AUMC) were significantly increased (p < 0.01; p < 0.001 respectively) by CP administration while the time to achieve the peak was reduced in the presence of CP. We conclude that administration of CP increased CQ uptake as judged by an increase in the maximum concentration (Cmax) and a decrease in the time to attain the concentration (Tmax), as well as an increase in the area under the curve, which signifies increased systemic availability of CQ in the presence of CP.

Nigerian Quarterly Journal of Hospital Medicine Vol.9, No.3 (1999) pp. 225-230