Aptazapine
Aptazapine is a tetracyclic antidepressant that was assayed in clinical trials for the treatment of depression in the 1980s but was never marketed. It is a potent alpha-2 [adrenergic receptor|α2-adrenergic receptor] antagonist with about 10 times the strength of the related compound mianserin and has also been shown to act as a 5-HT2 receptor antagonist and H1 receptor inverse agonist, while having no significant effects on the reuptake of serotonin or norepinephrine. Based on its pharmacological profile, aptazapine may be classified as a noradrenergic and specific [serotonergic antidepressant].