Acute cardiovascular effects of tranylcypromine: correlation with plasma drug, metabolite, norepinephrine, and MHPG levels.

BACKGROUND

Recent case reports, small series, and uncontrolled, unblinded studies have suggested that tranylcypromine may produce pressor reactions in some patients. However, the physiologic mechanism underlying this cardiovascular change is unknown.

METHOD

The authors studied the acute cardiovascular effects of tranylcypromine in 13 patients and attempted to correlate these changes with plasma measures of parent drug, possible pressor metabolites, norepinephrine, and 3-methoxy-4-hydroxyphenylglycol.

RESULTS

Significant elevations in supine blood pressure occurred after administration of tranylcypromine and correlated with tranylcypromine dose. Similar changes were not observed in standing blood pressure measurements. In fact, an orthostatic decrease in blood pressure and increase in heart rate were observed. Amphetamine-like metabolites were not found.

CONCLUSIONS

The authors speculate on possible mechanisms underlying these opposite cardiovascular effects.