Determination of chloroquine and monodesethylchloroquine in hair

Using thin-layer and gas chromatography and mass spectrometry, chloroquine and its major metabolite (monodesethylchloroquine) were identified in hair samples of numerous patients who received this antimalarial drug for several months. In two patients the amounts of chloroquine were, respectively, 310 and 145 mg/kg hair and those of the monodesethylchloroquine 23 and 11 mg/kg. The respective proportions (93 and 7%) are the same in the two subjects. The chloroquine percentage was near those in the spleen or stomach wall after poisoning. Other metabolites in hair are being identified. Hair analysis may provide a good toxicologic and forensic science complement to the blood, urine, and tissues. It may be useful for the control of chloroquine therapy.