Summary
Prazosin has reached the approved stage (maximum clinical phase 4) for at least one indication, so its use in Benign Prostatic Hyperplasia (BPH) would be drug repurposing rather than first-in-human development. This does not mean it is approved for Benign Prostatic Hyperplasia (BPH). ClinicalTrials.gov lists 8 registered trials linking Prazosin to Benign Prostatic Hyperplasia (BPH): 6 have completed; 2 are terminated, withdrawn, suspended or of unknown status. The most advanced is Phase 4 (NCT00922506). The largest enrolment is 35032 participants (NCT01323998). Registration activity spans 1995 to 2013. The literature layer holds 8 publications for this pair: 1 Cochrane review, 2 randomised controlled trial publications and 5 clinical trial publications. Publication years run from 1993 to 2024. Because at least one synthesis-level source exists (systematic review, meta-analysis or Cochrane review), this pair has been assessed beyond single studies, although the synthesis may concern a different indication.
The RepurpOS disease-intelligence file for Benign Prostatic Hyperplasia ranks 50 candidate therapeutics from Open Targets, ChEMBL, DGIdb and PubMed; only a minority carry direct clinical evidence, and this page covers one of those. Spontaneous remission context recorded for the condition: Progressive natural history; symptoms worsen in 50-60% over 5 years without treatment; spontaneous improvement in 20-30% (particularly mild symptoms); acute urinary retention risk ~1-2%/year.
Evidence table
| Evidence tier | A · Strong |
|---|---|
| Evidence score | 63.5 (trials 22.5, literature 21.0, tier 15, approved bonus 5.0) |
| Registered trials | 8 total: 0 recruiting, 0 active / not yet recruiting, 6 completed, 2 other |
| Linked publications | 8 (5 clinical trial publications, 2 randomised controlled trial publications, 1 Cochrane review) |
| Agent type | Drug (Small molecule) |
| Development stage (any indication) | Approved |
| Mechanism / class | Not recorded |
| Data sources | Open Targets, ChEMBL |
| Linked via biomarker / target | ABCC8 |
How the evidence score is calculated
- Each registered trial scores by status (recruiting / active / enrolling 3, completed 2.5, not yet recruiting 2, unknown 1, terminated / withdrawn / suspended 0.5) plus a phase bonus (phase 3-4 +2, phase 2 +1, phase 1 +0.5). The trial component is capped at 30.
- Each literature item scores by design (Cochrane review 5, meta-analysis 4, systematic review 3, RCT 3, clinical trial publication 2, curated reference 1.5, other PubMed record 1). The literature component is capped at 30.
- The existing evidence tier adds 15 (A / Strong), 10 (B / Moderate), 5 (C / Preliminary) or 0 (D / Anecdotal).
- Agents approved for any indication (max clinical phase 4) add 5, because an approved agent has an established safety profile that lowers the barrier to repurposing trials.
- The score ranks what has been studied, not what works. It does not read effect sizes or directions of effect.
Registered clinical trials
| NCT ID | Title | Status | Phase | Enrolment |
|---|---|---|---|---|
| NCT00922506 | Combination Treatment With Doxazosin Plus TolterodineSR 2 mg Versus 4mg in Men With an Overactive Bladder (OAB) and Benign Prostatic Hyperplasia (BPH) 2009 | completed | Phase 4 | 83 |
| NCT00687388 | The Clinical Efficacy of Non-steroidal Anti-inflammation Drugs in Patients With Benign Prostatic Hyperplasia 2008 | withdrawn | Phase 4 | — |
| NCT00021814 | Medical Therapy of Prostatic Symptoms 1995 | completed | Phase 3 | 3,407 |
| NCT06282731 | The Changes of Urine Growth Factors Level 2013 | completed | Early Phase 1 | 74 |
| NCT00730418 | Effects of Chronic Use of Doxazosin in Men With Benign Prostatic Hyperplasia 2007 | completed | Not applicable | 25 |
| NCT01332487 | Evaluating the Impact of Early Versus Delayed 5 Alpha Reductase Inhibitor Treatment on the Risk of Emergent Surgery in Men With Benign Prostatic Hyperplasia 2010 | completed | Not applicable | 4,068 |
| NCT01323998 | Benign Prostatic Hypertrophy Treatment Patterns & Outcomes: Marketscan 2010 | completed | Not applicable | 35,032 |
| NCT00563485 | Randomized Trial Comparing Terazosin 5 mg Daily and Doxazosin GITS 4 mg Daily for Trial Without Catheter in Acute Urinary Retention With Long Term Follow up 2005 | terminated | Not applicable | 120 |
Published literature
- Cochrane review Association Between Alpha-1 Adrenoreceptor Antagonist Use and Cognitive Impairment: A Systematic ReviewKingsley R, Tyree S, Jarsania D et al. · International neurourology journal · 2024 · PMID 39363407
- Clinical trial publication Pumpkin seed oil (prostafit) or prazosin? Which one is better in the treatment of symptomatic benign prostatic hyperplasiaShirvan MK, Mahboob MR, Masuminia M et al. · JPMA. The Journal of the Pakistan Medical Association · 2014 · PMID 25252490
- Clinical trial publication Seidlitzia rosmarinus for lower urinary tract symptoms associated with benign prostatic hyperplasia: a pilot randomized controlled clinical trialHeidari M, Hosseinabadi R, Anbari K et al. · Complementary therapies in medicine · 2014 · PMID 25146062
- Clinical trial publication Comparison of 7 α(1)-adrenoceptor antagonists in patients with lower urinary tract symptoms associated with benign prostatic hyperplasia:a short-term crossover studyAraki T, Monden K, Araki M · Acta medica Okayama · 2013 · PMID 23970323
- Clinical trial publication Pharmacokinetics of doxazosin gastrointestinal therapeutic system after multiple administration in Korean healthy volunteersKwon YH, Gwak HS, Yoon SJ et al. · Drug development and industrial pharmacy · 2007 · PMID 17729099
- Clinical trial publication Comparison of prazosin, terazosin and tamsulosin in the treatment of symptomatic benign prostatic hyperplasia: a short-term open, randomized multicenter study. BPH Medical Therapy Study Group. Benign prostatic hyperplasiaTsujii T · International journal of urology : official journal of the Japanese Urological Association · 2000 · PMID 10843450
- Randomized controlled trial Comparison of tamsulosin with alfuzosin in the treatment of patients with lower urinary tract symptoms suggestive of bladder outlet obstruction (symptomatic benign prostatic hyperplasia). The European Tamsulosin Study GroupBuzelin JM, Fonteyne E, Kontturi M et al. · British journal of urology · 1997 · PMID 9352699
- Randomized controlled trial Alpha-blocking treatment with alfuzosin in symptomatic benign prostatic hyperplasia: comparative study with prazosin. The PRAZALF GroupBuzelin JM, Hebert M, Blondin P · British journal of urology · 1993 · PMID 7508331
Mechanism and notes
No mechanism of action is recorded for this pair in the source databases.
OSMF's existing evidence tier for this pair is A (Strong), derived from the strength of the disease association recorded in Open Targets and ChEMBL, in this case via the biomarker or target ABCC8. The tier describes how well the drug-disease link is documented, not how well the drug works.
Frequently asked questions
Is Prazosin approved for Benign Prostatic Hyperplasia (BPH)?
Prazosin has reached the approved stage (maximum clinical phase 4) for at least one indication, so its use in Benign Prostatic Hyperplasia (BPH) would be drug repurposing rather than first-in-human development. This does not mean it is approved for Benign Prostatic Hyperplasia (BPH). Approval status for the specific indication should always be confirmed with the relevant regulator and prescribing information.
Is Prazosin in clinical trials for Benign Prostatic Hyperplasia (BPH)?
ClinicalTrials.gov lists 8 registered trials linking Prazosin to Benign Prostatic Hyperplasia (BPH): 6 have completed; 2 are terminated, withdrawn, suspended or of unknown status. The most advanced is Phase 4 (NCT00922506). The largest enrolment is 35032 participants (NCT01323998). Registration activity spans 1995 to 2013.
What does the evidence show for Prazosin in Benign Prostatic Hyperplasia (BPH)?
Prazosin has both completed registered trials and synthesis-level publications linked to Benign Prostatic Hyperplasia (BPH). That is the strongest profile in this database, but the summaries here do not extract effect sizes, so read the linked reviews for direction and magnitude of benefit. OSMF's existing evidence tier for this pair is A (Strong), derived from the strength of the disease association recorded in Open Targets and ChEMBL, in this case via the biomarker or target ABCC8. The tier describes how well the drug-disease link is documented, not how well the drug works.
Cite this page
Data: ClinicalTrials.gov, PubMed, Open Targets, ChEMBL, DGIdb and the OSMF therapeutic agent database. Last updated 2026-07-06. Page built 2026-10-07.