Table 1.

Review of clinical studies.

Authors	n (number of patients)	Conclusions and limitations
Montorsi et al. (1997)	30	Alprostadil injections led to superior rate of return of adequate erections; no preoperative EF parameters, no questionnaire, small number of patients, short follow-up
Mulhall et al. (2005)	132	Pharmacologic penile rehabilitation protocol results in higher rates of spontaneous erections and erectogenic drug response; no placebo arm, strong patient selection bias, dropouts were not included
Montorsi et al. (2006)	80	No significant difference is IIEF scores of patients using on demand versus daily PDE5 inhibitors post-NSRRP; compliance not reported
Bannowsky et al. (2008)	43	Daily low-dose sildenafil leads to improved recovery of EF post-NSRRP (86% versus 66% placebo); small number of patients, not placebo-controlled, single center, only included patients who showed preserved EF post-operative with Rigiscan testing
Padma-Nathan et al. (2008)	76	First placebo-controlled trial suggesting benefit of daily PDE5 inhibitor use: nightly sildenafil increased return of spontaneous erections; low percentage (4%) considered responders in placebo arm, but strict definition of responders
McCullough et al. (2008)	54	Nightly sildenafil improved nocturnal erections versus placebo; nocturnal tumescence data do not necessarily correlate with clinically usable erections
Montorsi et al. (2008)	628	Nightly vardenafil did not have any effect beyond that of on demand use