title: Efficacy and safety of short- and long-term, regular and on-demand regimens of phosphodiesterase type 5 inhibitors in treating erectile dysfunction after nerve-sparing radical prostatectomy: a systematic review and meta-analysis.
abstract: BACKGROUND
  We performed a meta-analysis to evaluate the efficacy and safety of short-term (≤6 months) and long-term (>6 months), regular (OaD) and on-demand (PRN) regimens of phosphodiesterase type 5 inhibitors (PDE5-Is) in treating erectile dysfunction (ED) after nerve-sparing radical prostatectomy (NSRP).
  
  
  METHODS
  We conducted a literature search in August 2016. Sources included PubMed, EMBASE, and MEDLINE databases. The main outcome was International Index of Erectile Function-Erectile Function (IIEF-EF) domain score, and the secondary outcome was treatment-emergent adverse events (TEAEs).
  
  
  RESULTS
  Eight articles involving 13 randomized controlled trials (RCTs) were used in this analysis: they suggested that PDE5-Is can improve the IIEF-EF distinctly in comparison with placebo in short and long term (mean difference [MD]: 2.26, 95% confidence interval [CI]: 1.45-3.08,P<0.00001, and MD: 4.5, 95% CI: 3.6-5.4,P<0.00001), and long-term use of PDE5-Is (>6 months) can improve the IIEF-EF distinctly in comparison with short-term use of PDE5-Is (≤6 months) (MD: 3.9, 95% CI: 3.01-4.8,P<0.00001). OaD of PDE5-Is significantly improved the IIEF-EF compared to placebo in short and long term (MD: 4.08, 95% CI: 3.2-4.97,P<0.00001, and MD: 4.74, 95% CI: 3.79-5.69,P<0.00001). No significant differences were found in IIEF-EF changes between PRN and placebo (≤6 months) (MD: 2.64, 95% CI: -0.87 to 6.14,P=0.14), and between PRN and OaD group (>6 months) (MD: -0.58, 95% CI: -9.86 to 8.74,P=0.91). There were more TEAEs in PDE5-Is group in comparison with placebo (odds ratio [OR]: 1.55, 95% CI: 1.26-1.91,P<0.0001), and TEAEs in OaD group were not significantly different from those seen in PRN group (OR: 1.05, 95% CI: 0.78-1.4,P=0.77).
  
  
  CONCLUSIONS
  Our meta-analysis suggests that PDE5-Is are efficient and safe for treatment of ED after NSRP, and we should choose the regular regimen for short term and regular or on-demand regimen for long term. Further high-quality RCTs are needed to validate this result.
authors.affiliation: Beijing Tian Tan Hospital, Capital Medical University, Beijing, People's Republic of China.
authors.forename: Daxue
authors.initials: D
authors.lastname: Tian
authors.affiliation: Beijing Tian Tan Hospital, Capital Medical University, Beijing, People's Republic of China.
authors.forename: Xiao-Yan
authors.initials: XY
authors.lastname: Wang
authors.affiliation: Beijing Tian Tan Hospital, Capital Medical University, Beijing, People's Republic of China.
authors.forename: Huan-Tao
authors.initials: HT
authors.lastname: Zong
authors.affiliation: Beijing Tian Tan Hospital, Capital Medical University, Beijing, People's Republic of China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D004334:Drug Administration Schedule; D007172:Erectile Dysfunction / Q000188:drug therapy* / Q000209:etiology*; D006801:Humans; D008297:Male; D016017:Odds Ratio; D058986:Phosphodiesterase 5 Inhibitors / Q000008:administration & dosage* / Q000627:therapeutic use; D011468:Prostatectomy / Q000009:adverse effects*; D016032:Randomized Controlled Trials as Topic; D020127:Recovery of Function
chemical_list: D058986:Phosphodiesterase 5 Inhibitors
keywords: erectile dysfunction; meta-analysis; nerve-sparing radical prostatectomy; phosphodiesterase type 5 inhibitors