The absorption, distribution, and excretion in mice of the antimalarial mefloquine, erythro-2,8-bis(trifluoromethyl)-alpha-(2-piperidyl)-4-quinolinemethanol hydrochloride.

Following oral administration of 14C-labeled mefloquine hydrochloride to female mice, the drug was well absorbed and distributed throughout the body. At both 24 and 48 hr after dosing the majority of radiolabel remaining in the body was in the form of parent drug. The major route of radiolabel excretion was fecal after either oral or intraperitoneal administration, with approximately 20% in the urine by 240 hr. The elimination t1/2 of unchanged drug after oral or intraperitoneal dosing was 18.7 and 13.5 hr, respectively, for urine and 14.5 and 15.4 hr, respectively, for feces. The t1/2 of parent drug after oral administration was 17.0 hr for plasma and 18.6 hr for erythrocytes. The erythrocyte concentration of drug was approximately five times the plasma concentration.