Pain associated with prostaglandin E1-containing intracavernosal injection medication is associated with poor erectile function recovery after radical prostatectomy.

Abstract

Intracavernosal injection therapy is often used as second-line therapy for erectile dysfunction associated with radical prostatectomy when therapy with phosphodiesterase-5 inhibitors has failed, but prostaglandin E1-containing vasoactive agents are associated with penile pain in some men. To define the incidence of pain with prostaglandin E1-containing intracavernosal injectionmixtures for erectile dysfunction associated with radical prostatectomy when therapy with phosphodiesterase-5 inhibitors has failed, and whether painwasa predictor of erectile function recovery. Men who underwent radical prostatectomy andwerecommencedonintracavernosal injection within 12 months of radical prostatectomy were included. A pain visual analog scale (0-10) was used to assess the degree of pain. Erectile function recovery was defined asthe International Index of Erectile Function domain score ≥24using phosphodiesterase-5 inhibitors at 24months. The study included 566 patients, mean age was 58±14 (42-74) years. Duration post-radical prostatectomy at intracavernosal injection training was 3.5±3.5m. Nerve sparing status: bilateral 76%, unilateral 13%, and non-nerve sparing 11%. Incidence of pain with intracavernosal injection per nerve sparing status: bilateral 10% of patients, unilateral 32%, non-nerve sparing 92% (p<0.001). Median visual analog scale in those experiencing pain: bilateral 4 (interquartile range 3, 5), unilateral 5.5 (interquartile range 3, 6), non-nerve sparing 7 (interquartile range 3, 9) (p<0.001). Phosphodiesterase-5 inhibitors success at 24months (no pain vs. pain): bilateral 70%vs. 40% (p<0.001), unilateral 50%vs. 28% (p<0.001), non-nerve sparing 10%vs. 0% (p<0.001). On multivariate analysis, predictors of failure to respond to phosphodiesterase-5 inhibitors at 24months post-radical prostatectomy included baseline erectile function, increasing age, incomplete nerve-sparing surgery, and presence of pain. The presence of penile pain with intracavernosal injection is associated with poorer erectile function recovery post-radical prostatectomy. Incidence of pain is high in men with non-nerve sparing radical prostatectomy; older patient age, poorer nerve sparing, poor baseline erectile function, and the presence of penile pain with prostaglandin E1-containing intracavernosal injection medication, were predictive of poor erectile function recovery using phosphodiesterase-5 inhibitors at 24months.