PDE5 Inhibitors (Procedures)
Phosphodiesterase type 5 (PDE5) inhibitors are the first-line pharmacological treatment for erectile dysfunction. By inhibiting PDE5, they prevent the degradation of cyclic GMP, enhancing nitric oxide–mediated smooth muscle relaxation in the corpus cavernosum and facilitating erection in response to sexual stimulation. Available agents include sildenafil, tadalafil, vardenafil, and avanafil, with differences in onset, duration, and food/alcohol interactions.
This atlas page is the procedural / clinic-facing companion to the full PDE5 inhibitor pharmacology hub. Use this page for counseling, escalation, and sexual-medicine workflow; use the pharmacology page for drug-class depth, off-label indications, safety ceilings, and the full reference set.
Indications
| Indication | Practical role |
|---|---|
| Erectile dysfunction | First-line oral pharmacotherapy when sexual stimulation is possible and nitrates are not required[1] |
| LUTS / BPH | Tadalafil 5 mg daily only; especially useful when LUTS and ED coexist[2] |
| Penile rehabilitation after radical prostatectomy | Scheduled dosing, not purely on-demand dosing, is the evidence-supported rehabilitation strategy[3] |
| Peyronie's disease with ED | Treats concomitant ED; disease-modifying antifibrotic benefit remains exploratory |
| Recurrent ischemic priapism | Counterintuitive daily morning PDE5i can reduce recurrent episodes in selected patients[4] |
PDE5 inhibitors are not a definitive answer for every ED patient. Poor responders include men with severe diabetes, pelvic radiation injury, major neurogenic injury, severe veno-occlusive dysfunction, untreated hypogonadism, or incorrect use. Escalation should move deliberately to intracavernosal injections, intraurethral alprostadil, vacuum erection device, or penile prosthesis rather than repeating ineffective oral therapy indefinitely.
Mechanism & Agents
| Agent | Usual use pattern | Practical differentiator |
|---|---|---|
| Sildenafil | On-demand | High absolute efficacy; food and alcohol can blunt onset |
| Tadalafil | On-demand or daily | Longest duration; only PDE5i approved for LUTS/BPH |
| Vardenafil | On-demand | Avoid with congenital long-QT and class IA / III antiarrhythmics |
| Avanafil | On-demand | Fast onset; favorable adverse-effect profile |
The key counseling point is that PDE5 inhibitors do not create an erection without arousal. They preserve NO-driven cGMP signaling; if the upstream neural stimulus is absent or severely impaired, response falls and downstream therapies such as ICI become more reliable.
Key Steps
- Confirm the patient is safe for sexual activity and is not using nitrates.
- Clarify the goal: on-demand intercourse support, daily LUTS/ED therapy, or post-prostatectomy rehabilitation.
- Start with a sensible agent and dose, then titrate to effect rather than declaring early failure.
- Teach correct use: timing, food effect, need for stimulation, and the expected number of attempts before judging efficacy.
- Screen for reversible contributors: hypogonadism, medication effects, poorly controlled diabetes, untreated sleep apnea, depression, pelvic pain, and relationship barriers.
- If response is inadequate, switch agents or escalate to MUSE / ICI / VED / implant according to the patient's goals and manual comfort.
Failure rule. A patient has not truly "failed PDE5 inhibitors" until they have had multiple correctly timed attempts at an adequate dose, preferably with at least one alternative agent. For rehabilitation after radical prostatectomy, scheduled dosing has a different purpose than on-demand intercourse support, so the regimen should match the indication.
Outcomes & Evidence
Pooled ED-guideline data support PDE5 inhibitors as first-line therapy, with most trials showing clinically meaningful erectile-function improvement and response rates around two thirds of treated patients.[1] Tadalafil 5 mg daily improves LUTS/BPH symptom scores and is the only PDE5 inhibitor with that urologic label.[2]
For penile rehabilitation, the evidence favors scheduled dosing. A network meta-analysis of randomized trials found regular sildenafil 100 mg the best-supported rehabilitation strategy after nerve-sparing radical prostatectomy, while on-demand dosing did not perform like a rehabilitation protocol.[3]
For recurrent ischemic priapism, daily PDE5i is not acute treatment; it is preventive reconditioning. AUA/SMSNA guidance lists PDE5 inhibitors among preventive strategies, and retrospective data suggest fewer emergency visits with regimented therapy.[4]
Do not miss: the nitrate interaction is absolute. Sildenafil and vardenafil require at least a 24-hour washout before nitrates; tadalafil requires at least 48 hours.
References
1. Burnett AL, Nehra A, Breau RH, et al. "Erectile dysfunction: AUA guideline." J Urol. 2018;200(3):633-641. doi:10.1016/j.juro.2018.05.004
2. Pattanaik S, Mavuduru RS, Panda A, et al. "Phosphodiesterase inhibitors for lower urinary tract symptoms consistent with benign prostatic hyperplasia." Cochrane Database Syst Rev. 2018;11:CD010060. doi:10.1002/14651858.CD010060.pub2
3. Sari Motlagh R, Abufaraj M, Yang L, et al. "Penile rehabilitation strategy after nerve-sparing radical prostatectomy: a systematic review and network meta-analysis of randomized trials." J Urol. 2021;205(4):1018-1030. doi:10.1097/JU.0000000000001584
4. Bivalacqua TJ, Allen BK, Brock G, et al. "Diagnosis and management of priapism: AUA/SMSNA guideline." J Urol. 2022;208(1):43-52. doi:10.1097/JU.0000000000002757