Drug monitoring of quinine by HPLC in cerebral malaria with acute renal failure treated by haemofiltration.

The monitoring of quinine by HPLC in 3 patients suffering from cerebral malaria with acute renal failure and treated by haemofiltration is reported. The recommended dose of quinine in this situation is reduced to 10 to 15 mg.kg-1.day-1. However, in the first patient, when given quinine 10 mg kg-1.day-1 the plasma concentration was mainly below the recommended therapeutic range of 5 to 15 mg/l. In consequence, the dose of quinine in the second patient was elevated to quinine dihydrochloride 15.1 mg.kg-1.day-1 which produced plasma concentrations in the low therapeutic range. In the third patient, an unreduced dose of quinine dihydrochloride 25.7 mg.kg-1.day-1 was employed, resulting in plasma concentrations above 15 mg/l, which is generally assumed to be toxic, although, no sign of acute quinine toxicity was seen. The antimalarial effect in all three patients was satisfactory. Quinine was estimated in the haemofiltrate in two patients and was found to be below the limit of sensitivity (0.25 mg/l). Plasma quinine did not change during or shortly after haemofiltration. It is concluded that in case of acute renal failure in cerebral malaria the dose of quinine should be reduced, but that the common recommendation of 10 to 15 mg.kg-1.day-1 may be too low, and that haemofiltration has no marked influence on the total body clearance of quinine.