The pharmacokinetic properties of intramuscular quinine in Gambian children with severe falciparum malaria

Abstract
Plasma quinine concentrations were measured in 21 Gambian children with severe falciparum malaria after intramuscular administration of a 20 mg (salt) per kg loading dose of quinine dihydrochloride followed by 10 mg/kg at 12 h intervals. Quinine was well absorbed reaching mean peak concentrations of 15·6 (standard deviation [SD] 4·5) mg/litre in a median time of 3 h (range 1–6 h). A one compartment model was fitted to the plasma concentration-time profile. The mean estimated systemic clearance (C1/F) was 0·89 (SD 0·81) ml/kg/min and the mean elimination half life was 18·8 (SD 8·0) h. Two patients, one of whom died, had low plasma quinine levels which remained below 10 mg/litre. Mean peak and trough plasma concentrations after subsequent intramuscular doses ranged between 11·1 and 15·1 mg/litre. In most cases this dose regimen provided a satisfactory profile of blood concentrations for the treatment of severe malaria in children.