Sildenafil in the treatment of sexual dysfunction in spinal cord-injured male patients

Objectives: The aim of this study was to evaluate the efficacy and safety o f sildenafil in the treatment of erectile dysfunction (ED) in spinal cord-i njury (SCI) patients. Moreover, we looked for neurological conditions permi tting therapeutic success and for the ideal dose needed to achieve sufficie nt erections. Methods: 41 SCI patients were prospectively examined. Sexual dysfunction wa s assessed by means of anamnesis, the International Index of Erectile Funct ion (IIEF) questionnaire, and neurological examination. Psychogenic erectio n capacity was tested by audiovisual stimulation and reflexive erection usi ng a vibrator device. Neurophysiological recordings and cystomanometry were performed in parallel to clinical examinations. Neurophysiological recordi ngs included sympathetic skin responses (SSR), pudendus somatosensory evoke d potentials (pSSEP), and bulbocavernous reflex (BCR). Urodynamics aimed at classifying the neurogenic bladder dysfunction (upper motoneuron lesion ve rsus lower motoneuron lesion). Intracavernous injection tests with PGE1 wer e performed in all patients to exclude major organic disease. 50 mg sildena fil was first given 3 times. Thereafter, the doses were adapted according t o patients' reports. Results: Clinically, 28 subjects preserved either reflexive erections (24) or psychogenic erections (4), 11 had both types and only 2 presented with a complete loss of erection. 38 patients (93%) had a positive response to si ldenafil and reached a penile rigidity sufficient to permit sexual intercou rse. 3 patients dropped out because of non-response despite having increase d the dosis up to 100 mg. 22 patients (58%) showed functional erections 1 h after 50 mg sildenafil, whereas 14 (37%) required higher doses of 75-100 m g. By comparing the IIEF questionnaire scores before and after therapy, the re was a significant improvement in erectile function and intercourse satis faction from 9.2 +/- 4.4 SD) and 4.5 (+/- 2.5 SD) to 25.5 (+/- 4.2 SD) and 10.5 (+/- 2.1 SD) points, respectively (p < 0.05). Nearly 10% (4/41) suffer ed from side effects such as headache or dizziness. Two of them stopped the rapy because of the side effects. At least 36 patients (88%) continue treat ment with sildenafil. Absence of both psychogenic (nonsomesthetic supraspin ally elicited) and reflexive (somesthetic spinally elicited) erections, con firmed by urodynamical and electrophysiological findings (SSR perineum, BCR and pSSEP), seems to exclude a successful treatment. In contrast, SCI male patients with preserved function of at least one component of the erection phenomenon (psychogenic/reflexive) responded well to sildenafil and the do se required to achieve erections sufficient for sexual intercourse did not differ between the two groups. Conclusions: Sildenafil proves to be a valuable and safe therapeutic manage ment in ED of SCI patients. Therefore, patient acceptance and satisfaction are high. The most common dose required to achieve a satisfying erection is 50 mg. The efficacy of sildenafil depends on sparing of either sacral (S2- S4) or thoracolumbar (T10-L2) spinal segments which, in this study, have be en shown to be of relevance in mediating psychogenic erections in male SCI patients. Complete disturbance of any neurogenic impulses excludes successf ul treatment. Copyright (C) 2000 S. Karger AG. Basel.