Fengabine, a new GABAmimetic agent in the treatment of depressive disorders: an overview of six double-blind studies versus tricyclics.

Fengabine is a new GABAmimetic compound active in animal models predictive of antidepressant activity. The present overview reports the results of 6 double-blind trials versus tricyclics (TCAs) (3 in outpatients and 3 in inpatients). Overall, 398 adult patients (149 males and 249 females) were treated; 194 with fengabine and 204 with TCAs (98 clomipramine, 63 amitriptyline and 43 imipramine). 284 suffered from major depression (MD) (including major depressive disorder and bipolar disorder, depressed; DSM III) and 114 from minor depression (MiD) including dysthymic disorder, atypical depression and adjustment disorder with depressive mood (DSM III). Dosage ranged from 600 to 2,400 mg/day for fengabine and 50 to 200 mg/day for TCAs. Efficacy was evaluated with the HAM-D scale. 311 subjects (154 fengabine and 157 TCAs) ended the 4-week treatment period. Considering the whole sample and mean IAM-D scores, no significant differences emerged between the 2 treatment groups at any of the assessment periods. Because of a significant treatment x type of depression interaction, MD and MiD were analysed separately, and a different trend appeared in the 2 subgroups with TCAs behaving slightly better than fengabine in MD and fengabine performing slightly better than TCAs in MiD. Using the physician's clinical improvement, 74% of patients under fengabine and 72% of those under TCAs were rated as improved or much improved. Side effects, particularly of the anticholinergic type were significantly more frequent in the TCAs group. Gamma-GT were more frequently altered in the fengabine group (30.4 vs. 10.5%); this increase was interpreted as a consequence of enzymatic induction. Lastly, more patients taking fengabine exhibited an increase in cholesterol values.