Pharmacokinetic and toxicological profile of artemisinin compounds: an update

Artemisinin has been used effectively in malaria treatment. With the emerging resistance to malaria, the optimum and judicial use of the drug has become important. The drug metabolism and toxicology can have an impact on the therapeutic profile and clinical use of this antimalarial agent. In this review, we discuss the pharmacokinetics and toxicological aspects of artemisinin and its therapeutic implications. Artemisinins have several dosing routes including oral, intramuscular, intravenous and rectal. With repeated dosing, artemisinin has propensity for autoinduction, leading to decreased plasma levels on repeated dosing. Combination with other antimalarials in most cases did not influence the pharmacokinetics of artemisinins. Interactions with cytochrome P(450) inhibitors are known but these neither affect the efficacy nor the toxicity of the respective derivative. Artemisinins are generally regarded to be of low toxicity. Two major problems associated with them are neurotoxicity and reproductive toxicity. But the extent of this neurotoxicity is dependent on the nature of the compound, on the route of administration, and on the nature of the formulation. Moreover, it occurs in humans at very high doses. However, as a matter of precaution, the use of artemisinins in the first trimester of pregnancy has been contraindicated.