Long-term intracavernous therapy responders can potentially switch to sildenafil citrate after radical prostatectomy

To assess whether long-term users of intracavernous (IC) injections after radical prostatectomy can switch to oral therapy with sildenafil citrate.

Forty-nine patients (mean age 60.9 years) with erectile dysfunction after radical prostatectomy were identified as long-term users of IC injections (3.7 +/- 1.9 years). These patients received open-label treatment with sildenafil citrate (50 to 100 mg) for a minimum of 4 weeks or five attempts. The primary outcome measure of our study was assessed by the Sexual Health Inventory of Men (SHIM) questionnaire (International Index of Erectile Function-5 [IIEF]). A successful switch was prospectively defined as erection sufficient for vaginal penetration after sildenafil use and compliance to therapy. Patients were designated as responders or nonresponders on the basis of their ability to achieve vaginal penetration.

Of 49 patients, only 36 agreed to receive oral open-label sildenafil (50 to 100 mg) for a minimum of 4 weeks or five attempts. Prostaglandin E1 (PGE1) was used in 70% and triple therapy (PGE1, papaverine, and phentolamine) in the remaining 30%. Of the 36 patients, 15 (41%) successfully switched to sildenafil and discontinued IC injections. When the results were stratified by the type of IC solution, patients with high-dose triple therapy had a poor success rate of switch (7%) compared with patients using PGE1 treatment (67%). Of the 36 patients, 14 (38%) found sildenafil ineffective and continued using IC injections. Patients who switched to oral therapy had had a greater (P <0.001) total mean SHIM (IIEF-5) score with IC injections than those who did not switch (12.3 +/- 7.8 versus 20.0 +/- 4.9). Of the 36 patients, 7 (19%) found sildenafil alone to be suboptimal but continued using it, enhancing the efficacy of IC injections alone. The three predictive factors for a successful switch were high preoperative SHIM (IIEF-5) score, high post-IC injection SHIM score, and type of IC medication used (PGE1 alone versus high-dose triple therapy).

Long-term users of IC injection therapy can potentially switch to sildenafil citrate with acceptable sexual satisfaction. Patients will accept a lower degree of sexual satisfaction as measured by the IIEF-5 (SHIM) score if oral therapy is effective.