These studies report that artesunate at lower dosage levels (100 mg kg-1 i.v. or i.p.) in animals (the dosage of artesunate in human clinical use as an antimalarial is 2 mg kg-1 i.v.) had no significant systemic pharmacological effects, i.e. artesunate had a relatively high selectivity as an antimalarial. However, at higher dosage levels there was an appearance of sedative effects, lowered movement of synchronism, elevation of tolerated lack of oxygen, lowered body temperature, analgesia, muscle relaxation, tremor, convulsions, depressed respiration and heart beat, lowered blood pressure, and depressed activity of the gastrointestinal tract.