[Metabolism of Ro 21-5998 (mefloquine) in the rat (author's transl)].

After administration of 15 mg/kg 14C-Ro 21-5998/001 i.p. to rats, the metabolite patterns in feces, urine, bile and blood were compared. Metabolites from feces were identified by GC/MS, in all other cases by TLC. The main component in the feces consists of mefloquine (Ro 21-5998). In addition the acid Ro 21-5104, a derivative of mefloquine with a hydroxy group in the piperidine moiety (M 12), the alcohol Ro 14-0518 and a metabolite (M 4a), which is supposed to be a lactam, were shown to be present. The acid Ro 21-5104 is the main metabolite in the urine. The bile contains the parent compound Ro 21-5998, the acid Ro 21-5104 and the alcohol Ro 14-0518, partially as conjugates. The structurally investigated components account for about 40% of the administered dose. The blood contains the parent compound Ro 21-5998 and the acid Ro 21-5104 as main components. In comparing the various metabolite patterns, it can be summarized that that in urine is slightly different from those in bile (after hydrolysis of the conjugates), feces and blood which show more similarities between each other.