The effects of fluoxetine on several neurophysiological variables in patients with premature ejaculation

Purpose: Fluoxetine, a selective serotonin re-uptake inhibitor, has been shown to increase the intravaginal latency of patients with premature ejaculation. We demonstrated the effects of fluoxetine on intravaginal latency, penile sensory threshold, and variables of sacral evoked response and cortical somatosensorial evoked potential, in patients with premature ejaculation. Materials and Methods: Of 48 patients 40 who presented to our clinic with premature ejaculation met the study criteria, gave written or oral consent, and were divided randomly in a double-blind fashion into 2 groups of 20 patients. The study group received 20 mg. fluoxetine daily and the control group received placebo for I month. The patients were evaluated during visits before and after treatment for intravaginal latency, penile sensory threshold values, and the variables of sacral evoked response and cortical somatosensory evoked potential tests. Results: Patient ages, intravaginal latencies, penile sensory threshold values, and amplitudes and latencies of sacral evoked response and cortical somatosensory evoked potential tests in both groups were not significantly different at the beginning of treatment (p >0.05). At the end of treatment intravaginal latencies and penile sensory threshold values were increased in the study group compared to before treatment and the control group (p <0.05). No change was observed in either group for the amplitudes and latencies of sacral evoked response and cortical somatosensory evoked potential tests (p >0.05). Conclusions: These findings suggest that fluoxetine is effective treatment for premature ejaculation probably due to its effect of increasing the penile sensory threshold, without changing the amplitudes and latencies of sacral evoked response and cortical somatosensory evoked potential.