A pharmacokinetic study has been conducted in six beagle dogs after i.m. administration of 25 mg/kg of arteether, a qinghaosu (artemisinin) derivative of high anti-malarial activity. Arteether plasma concentrations were measured during a 24 h period using HPLC with an electrochemical detector in the reductive mode. The pharmacokinetic parameters were established using an open two-compartment model. Results showed a relatively rapid absorption phase: T1/2ka was 0.300 +/- 0.096 h and a mean elimination half-life of 27.95 +/- 11.93 h. Cmax was 110 +/- 16 ng/ml, Cltot/F was 1.69 +/- 0.34 ml/min and AUC was 2797 +/- 476 ng/ml/h.