The disposition of chloroquine and its main metabolite desethylchloroquinein volunteers with and without chloroquine-induced pruritus: Evidence for decreased chloroquine metabolism in volunteers with pruritus

The pharmacokinetics of chloroquine and its main metabolite desethylchloroq uine have been carried out in volunteers with and without chloroquine-induc ed pruritus, It was shown that the volunteers with pruritus tended to metab olize chloroquine slower than the volunteers without pruritus because the m etabolic ratio was lower in the volunteers with pruritus than that in the v olunteers without pruritus, However, the overall pharmacokinetic patterns w ere comparable between the two groups and agreed with published data. The 2 4-hour urinary collections in the two groups of volunteers indicated that t he volunteers with pruritus excreted more chloroquine (although not statist ically significant) than the volunteers without pruritus, This also indicat es that they metabolized less chloroquine, There were no side effects of no te in any of the volunteers. The volunteers who gave positive histories of chloroquine-induced pruritus had mild episodes of itching after intake of t he drug; the pruritus subsided within 48 hours in all instances.