Fengabine, a novel antidepressant GABAergic agent. I. Activity in models for antidepressant drugs and psychopharmacological profile.

Fengabine (SL 79.229) is a novel benzylidene derivative with clinically proven antidepressant action. Fengabine is active in behavioral models for antidepressant drug action, reversing the passive avoidance deficit in olfactory bulbectomized rats, antagonizing the escape deficit in the learned helplessness model and decreasing paradoxical sleep in the rat. In contrast to tricyclic antidepressants, fengabine antagonizes 5-hydroxytryptophan-induced head twitches and only weakly reverses reserpine-induced ptosis. Fengabine inhibits neither monoamine uptake nor monoamine oxidase. A GABAergic mechanism of fengabine is indicated as bicuculline reverses its action in the olfactory bulbectomy and learned helplessness models. The wide-spectrum anticonvulsant action of fengabine is consistent with a GABA-mimetic action and is in contrast to the proconvulsant effect of most classical antidepressants.