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Viagra (sildenafil citrate)
Sildenafil inhibits phosphodiesterase type 5 (PDE5), allowing cyclic GMP to accumulate and promote smooth muscle relaxation in the corpus cavernosum, increasing blood flow to the penis.
Sildenafil inhibits phosphodiesterase type 5 (PDE5), allowing cyclic GMP to accumulate and promote smooth muscle relaxation in the corpus cavernosum, increasing blood flow to the penis. Used for Erectile dysfunction, Pulmonary arterial hypertension, Benign prostatic hyperplasia symptoms.
At a glance
| Generic name | Viagra (sildenafil citrate) |
|---|---|
| Sponsor | Pfizer's Upjohn has merged with Mylan to form Viatris Inc. |
| Drug class | Phosphodiesterase type 5 (PDE5) inhibitor |
| Target | PDE5 (phosphodiesterase type 5) |
| Modality | Small molecule |
| Therapeutic area | Urology / Cardiovascular |
| Phase | FDA-approved |
Mechanism of action
PDE5 normally breaks down cyclic GMP, a signaling molecule that relaxes smooth muscle. By blocking PDE5, sildenafil allows cGMP levels to rise, leading to vasodilation and increased penile blood flow during sexual stimulation. This mechanism also applies to pulmonary and systemic vasculature, explaining its use in pulmonary hypertension and other vascular conditions.
Approved indications
- Erectile dysfunction
- Pulmonary arterial hypertension
- Benign prostatic hyperplasia symptoms
Common side effects
- Headache
- Flushing
- Dyspepsia
- Nasal congestion
- Back pain
- Myalgia
- Vision abnormalities (blue-tinted vision)
Key clinical trials
- Radial Shockwave Therapy for Erectile Dysfunction (NA)
- Asciminib With or Without Sildenafil for Brain Tumors (EARLY_PHASE1)
- Safety of Sildenafil in Premature Infants (PHASE2)
- Sildinafil in Pulmonary Hypertension-Rheumatic Chronic Valvular Disease(RCT) (PHASE2, PHASE3)
- Oral Sildenafil for Exercise Capacity, Dyspnea and Cardiopulmonary Function in COPD (PHASE2)
- Interest of Early Erectile Rehabilitation With Sildenafil After Radiotherapy and Proctectomy for Rectal Cancer (PHASE3)
- Sildenafil Plus Hypothermia to Treat Neonatal Encephalopathy (PHASE2)
- Mono vs. Dual Therapy for Pediatric Pulmonary Arterial Hypertension (PHASE3)
Primary sources
Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.
| Source | Used for |
|---|---|
| ClinicalTrials.gov | Trial enrolment, design, endpoints, results |
Competitive intelligence
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