Pharmacokinetic aspects of deprenyl effects.

Deprenyl is a selective, irreversible inhibitor of monoamine oxidase type-B (MAO-B). In prolonged treatment (0.05-0.25 mg/kg, sc daily) in spite of the irreversible blocking, selective inhibition pattern of MAO was maintained. 14C-Deprenyl is well absorbed after oral or subcutaneous administration and penetrates rapidly to the central nervous system. When it is given intravenously its highest brain concentration is reached within 30 sec but radioactivity rapidly disappears from the central nervous system. Deprenyl is metabolized to amphetamine and methylamphetamine in rats without producing a remarkable sign of psychostimulant activity. This could partly be due to the distribution properties of deprenyl e.g. low detectable level of radioactivity in the brain after 1-2 min and partly to the fact that from (-) -deprenyl (-) -amphetamines, which have less psychostimulant activity than the (+) -isomere, are formed.