A comparative study on desipramine pharmacokinetics in the rat brain after administration of desipramine or imipramine.

Chronic intraperitoneal administration of desipramine led to an extensive cumulation of the drug in brain and blood compared with that after a single dose treatment, while chronic treatment with desipramine by the oral route produced a brain concentration comparable with its level after a single oral dose. Comparison of the present results with the corresponding data of published imipramine pharmacokinetics indicated that the cumulation of desipramine in the rat brain was nearly the same when rats received desipramine or imipramine twice a day for two weeks at a dose of 10 mg kg-1 orally, or imipramine, twice a day for two weeks at a dose of 10 mg kg-1 intraperitoneally. It is suggested that these three experimental paradigms may be used as models for differentiation of the pharmacological effects of imipramine and desipramine in-vivo.