Ten Years of Phosphodiesterase Type 5 Inhibitors in Spinal Cord Injured Patients

The majority of men with spinal cord injury (SCI) require chronic treatment for erectile dysfunction (ED), but most of them, prior to taking phosphodiesterase type 5 (PDE5) inhibitors, stopped therapy due to side-effects or low compliance rate. Analysis of literature on oral PDE5 inhibitors in individuals with SCI and ED in order to evaluate how much their release changed the management of ED in SCI subjects and what remains to be seen of their potential or limits. Questionnaires on sexual function. 18 internationally published clinical studies that enrolled SCI males treated with at least one of the PDE5 inhibitors were analyzed. The small numbers of papers with large and diverse outcome measures did not consent a meta-analysis of treatment results. 705 used sildenafil, 305 vardenafil and 224 tadalafil. Median age was less than 40 years. Only 1 study excluded tetraplegic individuals. For measures of ED evaluated, 11 out of 13 studies reported a significant statistical improvement with PDE5 inhibitors versus placebo or erectile baseline (P < 0.01, or p < 0.005). The most frequent predicable factor for the therapeutic success of PDE5 inhibitors was upper motoneuron lesion. Statistical impact on ejaculation success rates was shown in at least one paper for all PDE5 inhibitors (p < 0.05). Overall, 15 patients, (7 using sildenafil), discontinued the therapies due to drawbacks. Only 1 sildenafil study reported a follow-up maximum of 24 months. Literature suggests that all oral PDE5 inhibitors represent a safe and effective treatment option for ED caused by SCI. Further research is needed on head-to-head comparative trials and SCI patient preference for these drugs; their impact on ejaculation and orgasm function, their early use after SCI for increasing the recovery rate of a spontaneous erection, and their effectiveness and tolerability in the long-term are still to be investigated. Lombardi G, Macchiarella A, Cecconi F, and Del Popolo G. Ten years of phosphodiesterase type 5 inhibitors in spinal cord injured patients. J Sex Med 2009;6:1248-1258.