A COMPARISON OF SUBJECTIVE RESPONSES TO IMIPRAMINE AND TRANYLCYPROMINE

Although the number of anti-depressant drugs available has grown rapidly in recent years, they are still broadly classified into three main groups. First are the general nervous system stimulants, exemplified by amphetamine, second the group derived from the phenothiazines exemplified by imipramine and third, the monoamineoxidase inhibitors—the first example of which was iproniazid. The general stimulants have many disadvantages, their place in treatment is limited, but fairly well defined. Many monoamineoxidase inhibitors have been found to have serious toxic effects, but some, including tranylcypromine appear to be reasonably safe and effective (Agin, 1960).

TRANYLCYPROMINE CEPHALGIA

Tranylcypromine, a useful antidepressant agent, has been linked with a clinical syndrome of undetermined incidence characterized by exceedingly severe and prolonged headache. Associated phenomena may include paroxysmal hypertension, pallor, chest pain and collapse. This violent reaction does not seem to be related to age, sex, duration of treatment, or pre-existing cardiovascular disease; nor is it possible to predict in whom it will occur. The clinical picture may sometimes be quite similar to that produced by subarachnoid hemorrhage or by pheochromocytoma. The mechanism of action is not known, although it is possible that the syndrome may be due to an amphetamine-like effect; i.e., that tranylcypromine influences the adrenergic component of the reticular activating system. The occurrence of severe headache in the course of tranylcypromine therapy is an indication for immediate withdrawal of the drug. Tranylcypromine cephalgia should be considered as part of the differential diagnosis of sudden, violent and prostrating headache.

THE EFFECT OF AMINE OXIDASE INHIBITORS ON PREGNANCY

The effects of seven amine oxidase inhibitors on pregnancy were investigated in mice. Four of the compounds were derivatives of hydrazine and three were not. All the derivatives of hydrazine and one of the other compounds tested produced toxic effects in early pregnancy but were relatively inactive later.

The effect of one of the compounds investigated (HP 1325) was, to a great extent, reversed by either progesterone or prolactin, suggesting an interference with the hormonal mechanism responsible for the maintenance of pregnancy.

HP 1325 (and 5-hydroxytryptamine) did not interrupt pseudopregnancy, indicating that luteal function is not completely inhibited.

Evidence is adduced that the effects on pregnancy are not related to any particular chemical structure or to the amine-oxidase activity of the compound tested.