URINARY-EXCRETION OF BIOACTIVE AMINES AND THEIR METABOLITES IN PSYCHIATRIC-PATIENTS RECEIVING PHENELZINE

Phenelzine 2-phenylethylhydrazine! (PLZ), a potent inhibitor of monoa mine oxidase (MAO)-A and -B, is used widely in psychiatry. We have stu died the effects of PLZ administration on urinary excretion of several bioactive amines and their metabolites in psychiatric patients. Urine samples (24-hour) were collected prior to treatment and again at 2 an d 4 weeks of treatment with PLZ (30-90 mg daily in divided doses). Ami nes and metabolites analyzed included 2-phenylethylamine (PEA), m- and p-tyramine (m- and p-TA), phenylacetic acid (PAA), m- and p-hydroxyph enylacetic acid (m- and p-OH-PAA), tryptamine (T), 5-hydroxytryptamine (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), normetanephrine (NME), 3 -methoxy-4-hydroxyphenylglycol (MHPG), 3-methoxytyramine (3-MT), and h omovanillic acid (HVA). Levels of PEA, p-TA, 5-HT, and T were elevated during treatment with PLZ, but no significant changes in urinary excr etion of the acid metabolites PAA, p-OH-PAA, and 5-HIAA were observed. Urinary levels of the noradrenaline metabolites NME and MHPG were inc reased and decreased, respectively; a similar pattern was observed wit h the dopamine metabolites 3-MT and HVA. There was an elevation in lev els of m-TA and a decrease in its acid metabolite m-OH-PAA during the treatment with PLZ.