The Problem After TURP
Transurethral resection of the prostate (TURP) has been the gold standard surgical treatment for benign prostatic hyperplasia (BPH) for decades. The procedure effectively relieves bladder outlet obstruction, improves urinary flow, and reduces lower urinary tract symptoms (LUTS). For most men with significant BPH, TURP provides substantial and durable improvement in quality of life.
However, TURP is not without consequences. Two specific problems affect a meaningful number of men after surgery. The first is erectile dysfunction. The cavernous nerves, which control penile erections, run close to the prostate capsule. The thermal energy used during TURP can damage these nerves, leading to temporary or permanent erectile dysfunction. Reported rates of de novo ED after TURP range from 10% to 30%.
The second problem is persistent storage symptoms. Storage symptoms include urinary frequency, urgency, and nocturia the bothersome sensations that make men feel they need to urinate constantly, even when the bladder is not full. While TURP effectively relieves voiding symptoms (weak stream, hesitancy), 20% to 30% of men continue to experience significant storage symptoms after surgery. These persistent symptoms negatively impact quality of life and sometimes require additional medication.
Phosphodiesterase type 5 inhibitors (PDE5-Is), such as tadalafil, are well known for treating erectile dysfunction. More recently, tadalafil 5 mg once daily has been approved for the treatment of LUTS secondary to BPH, even in men without ED. The proposed mechanism involves relaxation of smooth muscle in the bladder neck and prostate via the nitric oxide-cyclic GMP pathway.
Given these dual effects improving erections and reducing LUTS researchers have hypothesized that early administration of tadalafil after TURP might accelerate recovery of erectile function and reduce persistent storage symptoms. A randomized controlled trial by Taha and colleagues (2025) tested this hypothesis directly.
Study Design
The investigators conducted a double-blind, placebo-controlled randomized trial at a tertiary care hospital in Egypt between May 2021 and October 2022. All enrolled patients underwent TURP for BPH. They were randomly assigned in a 1:1 ratio to one of two groups.
Group A (n = 103) received tadalafil 5 mg once daily, starting one week after TURP.
Group B (n = 92) received an identical placebo.
The treatment continued for six months. Patients were evaluated before surgery and at 1, 3, and 6 months after TURP. Erectile function was measured using the International Index of Erectile Function-5 (IIEF-5), a validated 5-question scale where scores range from 5 (severe ED) to 25 (normal). Lower urinary tract symptoms were measured using the International Prostate Symptom Score (IPSS) total score and the IPSS storage subscore, which specifically captures frequency, urgency, and nocturia.
All patients were sexually active before surgery. Men who were sexually inactive were excluded from analyses of erectile function because the IIEF-5 is not validated in that population.
The primary outcomes were erectile function (IIEF-5 score) and persistent storage symptoms (IPSS storage subscore) at 1, 3, and 6 months after TURP.
Results: Erectile Function
The most striking finding of this trial involves erectile function. At baseline, the two groups had similar IIEF-5 scores. Group A (tadalafil) had a mean of 9.84, indicating moderate erectile dysfunction. Group B (placebo) had a mean of 10.43, also moderate ED.
The trajectories after surgery diverged dramatically.
In Group B (placebo), erectile function worsened significantly at one month. The mean IIEF-5 dropped from 10.43 to 4.88 severe erectile dysfunction. This decline likely reflects thermal injury to the cavernous nerves during TURP, combined with postoperative pain and cessation of sexual activity. By three months, the placebo group began to recover, reaching 12.86. At six months, the mean IIEF-5 was 15.32, still moderate ED but improving.
In Group A (tadalafil), the pattern was completely different. There was no postoperative decline in erectile function. Instead, the mean IIEF-5 increased from 9.84 at baseline to 11.59 at one month, then to 19.80 at three months, and finally to 20.97 at six months. The last value represents mild or no erectile dysfunction (normal is 22-25).
| Time point | Group A (tadalafil 5 mg) | Group B (placebo) | Difference | p-value |
| Baseline (pre-TURP) | 9.84 | 10.43 | -0.59 | 0.131 |
| 1 month post-TURP | 11.59 | 4.88 | +6.71 | <0.001 |
| 3 months post-TURP | 19.80 | 12.86 | +6.94 | <0.001 |
| 6 months post-TURP | 20.97 | 15.32 | +5.65 | <0.001 |
*IIEF-5 range: 5-25 (higher is better). Minimal clinically important difference is approximately 4 points.*
The differences between groups were highly statistically significant (p < 0.001) at all postoperative time points. The magnitude of the difference approximately 5 to 7 points on the IIEF-5 is clinically meaningful. For a man in the placebo group, his erection at six months was still moderately impaired. For a man in the tadalafil group, his erection was nearly normal.
Results: Persistent Storage Symptoms
The effect on storage symptoms was more modest. Both groups showed substantial improvement from baseline. The mean IPSS storage subscore in Group A fell from 8.63 before surgery to 0.92 at six months. In Group B, it fell from 8.03 to 1.69.
While the difference between groups was statistically significant (p < 0.001), the absolute difference was small approximately 0.8 points on the storage subscore, which ranges from 0 to 15. The authors themselves describe this effect as “modest.”
For total IPSS (voiding plus storage symptoms), both groups improved dramatically from approximately 24 to approximately 2-3. There was no significant difference between groups. Similarly, maximum urinary flow rate (Qmax) and post-void residual volume (PVR) improved equally in both groups. Tadalafil did not enhance the urodynamic outcomes of TURP.
The authors note an important distinction. Tadalafil 5 mg daily after TURP significantly improves erectile function. It has a small, statistically significant but clinically modest effect on persistent storage symptoms. It does not improve flow rates or residual urine beyond what TURP alone achieves.
Two Key Takeaways from the Taha Trial
- Early administration of tadalafil 5 mg daily after TURP significantly improves erectile function compared to placebo. The effect is large (5-7 points on IIEF-5), begins within the first month, and persists through six months. Men in the tadalafil group achieved near-normal erections (IIEF-5 20.97) while placebo-treated men remained moderately impaired (IIEF-5 15.32) at six months.
- The effect on persistent storage symptoms is statistically significant but clinically modest. Tadalafil reduced storage symptoms slightly more than placebo, but the absolute difference was small. Tadalafil did not improve flow rates or post-void residual beyond what TURP alone achieved.
Limitations of the Study
The Taha trial has several limitations that readers should understand when interpreting the results. The authors acknowledge most of these in their discussion.
Limitations of the Taha Trial
- Modest sample size. Although 195 patients is respectable for a randomized trial, the authors note that larger studies would provide more robust conclusions. The study was conducted at a single tertiary center in Egypt, which may limit generalizability to other populations.
- Follow-up of only six months. The trial does not tell us whether the benefits of tadalafil persist beyond six months. Longer-term data are needed to determine if men can eventually stop the medication or if continued daily use is necessary to maintain erectile function.
- No comparison between daily and on-demand dosing. The study used a fixed daily dose of 5 mg. Whether on-demand tadalafil at higher doses (10-20 mg) would produce similar or better results is unknown.
- Sexually inactive men were excluded from erectile function analyses. This is methodologically correct because IIEF-5 is not validated in sexually inactive men, but it means the results apply primarily to men who were sexually active before surgery. The effect of tadalafil on erectile function in men who were not sexually active before TURP remains unknown.
- No assessment of partner satisfaction or quality of sexual life. The study measured erectile function using a validated questionnaire but did not assess whether the improvements translated into better relationship satisfaction or overall sexual quality of life.
- Potential for unmeasured confounders. Although the trial was randomized and double-blinded, the authors did not report on factors such as the specific surgical technique (monopolar vs bipolar TURP), the amount of prostate tissue resected, or the degree of nerve-sparing, all of which could affect postoperative erectile function.
Comparison with Previous Research
The findings of the Taha trial align with some previous studies but diverge from others. Understanding these comparisons provides important context.
Effect on erectile function. A meta-analysis by Goh and colleagues (2022) found that PDE5 inhibitors promote recovery of erectile function after nerve-sparing radical prostatectomy. The Taha trial extends this finding to TURP, where nerve injury is less severe but still clinically significant. The magnitude of benefit (approximately 5-7 points on IIEF-5) is comparable to that seen in prostatectomy trials.
Effect on LUTS. Multiple randomized trials and meta-analyses have shown that tadalafil 5 mg daily improves LUTS in men with BPH who have not undergone surgery (Cui et al., 2021; Porst et al., 2011). However, the Taha trial found only a modest effect on persistent storage symptoms after TURP, and no effect on voiding symptoms or flow rates. This suggests that once the prostate tissue has been resected, the mechanism by which PDE5 inhibitors relieve LUTS smooth muscle relaxation in the bladder neck and prostate may have less room to work. The bladder is no longer obstructed, so additional relaxation produces little additional benefit.
Effect on flow rate. Laydner and colleagues (2011) conducted a systematic review and found that PDE5 inhibitors improve IPSS and IIEF scores but do not significantly affect maximum flow rate (Qmax). The Taha trial confirms this finding in the post-TURP population. Tadalafil did not improve Qmax beyond what TURP alone achieved.
Mechanistic Implications
The differential effect of tadalafil on erectile function versus storage symptoms provides insight into the underlying mechanisms of TURP-related sexual dysfunction. The sharp decline in IIEF-5 scores at one month in the placebo group (from 10.43 to 4.88) reflects the combined impact of nerve injury, inflammation, and psychological factors. Tadalafil prevented this decline entirely, likely through its vasodilatory and neuroprotective effects. The cavernous nerves, though thermally injured, may benefit from increased blood flow and cyclic GMP signaling during the healing phase.
In contrast, persistent storage symptoms after TURP appear to be driven primarily by bladder wall changes that are not fully reversed by PDE5 inhibition. The modest effect of tadalafil suggests that other mechanisms such as bladder denervation, chronic inflammation, or altered sensory signaling may be more important.
Clinical Application
For urologists managing patients after TURP, the Taha trial provides actionable evidence. Early initiation of tadalafil 5 mg daily (beginning one week after surgery) significantly improves erectile function recovery. The benefit is large, begins within the first month, and persists through at least six months. The medication is well tolerated, with only 13 of 103 patients reporting mild headaches or nasal congestion, none requiring discontinuation.
However, clinicians should set appropriate expectations regarding storage symptoms. Tadalafil provides only a small additional benefit beyond TURP alone. Patients with bothersome persistent frequency, urgency, or nocturia should not expect tadalafil to resolve these symptoms completely. Other treatments such as antimuscarinics, beta-3 agonists, or behavioral therapy may still be needed.
At Adult & Pediatric Urology (APUMN), we incorporate the findings of this randomized controlled trial into our postoperative protocol for sexually active men undergoing TURP. For men who are good candidates for PDE5 inhibitor therapy (no nitrates, no significant hypotension), we discuss early initiation of tadalafil 5 mg daily to optimize erectile function recovery. We also counsel patients that the effect on storage symptoms is modest and that persistent bothersome symptoms should be evaluated separately.
Conclusion for Patients and Clinicians
The Taha trial answers an important clinical question. Does early tadalafil after TURP help? For erectile function, the answer is a clear yes. Daily tadalafil 5 mg started one week after surgery produces substantially better erections than placebo, with effects that are large, early, and sustained through six months. For persistent storage symptoms, the answer is a qualified yes there is a small statistically significant benefit, but it is clinically modest.
Men undergoing TURP who are concerned about postoperative erectile dysfunction should discuss daily tadalafil with their urologist. The medication is safe, well tolerated, and effective. Men who are primarily concerned about persistent urinary frequency or urgency after TURP should understand that tadalafil is not a reliable solution other treatments may be needed.
This trial represents an important advance in post-TURP care, shifting the focus from simply monitoring erectile dysfunction to actively treating it with early, evidence-based intervention.
Author
Gregory S. Parries, M.D., PhD
