Whole blood concentrations of chloroquine and desethylchloroquine during and after treatment of adult patients infected with Plasmodium vivax, P. ovale or P. malariae.

Whole blood concentrations of chloroquine and desethychloroquine were determined during and after chloroquine treatment of 15 adult patients infected with P. vivax, P. ovale or P. malariae. The median of chloroquine concentrations remained practically unchanged in samples drawn three hours after initiation of treatment and in samples drawn immediately before the next dose of chloroquine. Concentrations of chloroquine remained above 1.0 mumol/litre for at least four days. The calculated sum of chloroquine and desethylchloroquine concentrations was above 1.0 mumol/litre for at least seven days. These concentrations are regarded as sufficient for treatment of P. vivax, P. ovale and P. malariae infections.