Subchronic treatment with fluoxetine attenuates the proerectile effect of Aspidosperma ulei Markgr (Apocyanaceae)

OBJECTIVE: To evaluate the ability of acute or chronic treatment with fluoxetine to alter the proerectile effect of Aspidosperma ulei alkaloid-rich fraction (F3-5). MATERIALS AND METHODS: In the first series of experiments, three groups of mice received either a single intraperitoneal injection of vehicle, F3-5 (25 mg/kg) or fluoxetine (10 mg/kg) + F3-5. Three behavioral responses were counted over a period of 30 min: erection, erection-like response and genital grooming. In a second series of experiments, animals treated for 13 days with fluoxetine or fluoxetine + F3-5 were assessed. RESULTS: A. ulei has been suggested to have proerectile effect in mice. Subchronic (13-d) treatment with fluoxetine resulted in a reduction in the number erections in F3-5-treated mice. CONCLUSION: Sexual dysfunction associated with antidepressant treatment continues to be a major compliance issue for antidepressant therapy. Acute administration of fluoxetine resulted in a near total reversal of the proerectile effect of F3-5.