Published online by Cambridge University Press: 09 July 2009
The activity of platelet monoamine oxidase(MAO)was measured in 22 severely depressed patients before and after treatment with 45 mg and 60 mg phenelzine. The per cent inhibition of platelet MAO after both doses was not related to acetylator status.
Phenelzine, since it is a hydrazine derivative, is probably metabolized by polymorphic acetylation. Patients who were phenotypically slow acetylators have been reported to show a better clinical response (Johnstone & Marsh, 1973) and more side-effects (Evans et al. 1965) to a given dose of phenelzine than patients who were fast acetylators.