Summary
Prazosin has reached the approved stage (maximum clinical phase 4) for at least one indication, so its use in Insomnia / Sleep Disorders would be drug repurposing rather than first-in-human development. This does not mean it is approved for Insomnia / Sleep Disorders. ClinicalTrials.gov lists 1 registered trial linking Prazosin to Insomnia / Sleep Disorders: 1 has completed. None of the registered studies carries a drug-development phase label, which is typical for behavioural, device and supplement protocols. It plans or enrolled 50 participants. Registered activity dates to 2006. The literature layer holds 5 publications for this pair: 2 meta-analyses and 3 clinical trial publications. Publication years run from 2008 to 2025. 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 Insomnia ranks 317 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: Acute insomnia (<3 months): 50-60% resolve spontaneously; chronic insomnia: only 20-25% spontaneous remission at 1 year; persistent insomnia in 50-75% without treatment.
Evidence table
| Evidence tier | A · Strong |
|---|---|
| Evidence score | 36.5 (trials 2.5, literature 14.0, tier 15, approved bonus 5.0) |
| Registered trials | 1 total: 0 recruiting, 0 active / not yet recruiting, 1 completed, 0 other |
| Linked publications | 5 (3 clinical trial publications, 2 meta-analyses) |
| Agent type | Drug (Small molecule) |
| Development stage (any indication) | Approved |
| Mechanism / class | Not recorded |
| Data sources | Open Targets, ChEMBL |
| Linked via biomarker / target | ADCY2 |
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trial scores by status (recruiting / active / enrolling 3, completed 2.5, not yet recruiting 2, unknown 1, terminated / withdrawn / suspended 0.5) plus a phase bonus (phase 3-4 +2, phase 2 +1, phase 1 +0.5).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 |
|---|---|---|---|---|
| NCT00393874 | Efficacy of Sleep Interventions for Posttraumatic Stress Disorder (PTSD) 2006 | completed | Not applicable | 50 |
Published literature
- Meta-analysis Factors impacting prazosin efficacy for nightmares and insomnia in PTSD patients - a systematic review and meta-regression analysisMendes TP, Pereira BG, Coutinho ESF et al. · Progress in neuro-psychopharmacology & biological psychiatry · 2025 · PMID 39828080
- Meta-analysis Pharmacotherapy for sleep disturbances in post-traumatic stress disorder (PTSD): A network meta-analysisLappas AS, Glarou E, Polyzopoulou ZA et al. · Sleep medicine · 2024 · PMID 38795401
- Clinical trial publication A Pilot, Randomized Clinical Trial of Bedtime Doses of Prazosin Versus Placebo in Suicidal Posttraumatic Stress Disorder Patients With NightmaresMcCall WV, Pillai A, Case D et al. · Journal of clinical psychopharmacology · 2018 · PMID 30335633
- Clinical trial publication Prazosin for Veterans with Posttraumatic Stress Disorder and Comorbid Alcohol Dependence: A Clinical TrialPetrakis IL, Desai N, Gueorguieva R et al. · Alcoholism, clinical and experimental research · 2016 · PMID 26683790
- Clinical trial publication Prazosin effects on objective sleep measures and clinical symptoms in civilian trauma posttraumatic stress disorder: a placebo-controlled studyTaylor FB, Martin P, Thompson C et al. · Biological psychiatry · 2008 · PMID 17868655
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 ADCY2. The tier describes how well the drug-disease link is documented, not how well the drug works.
Frequently asked questions
Is Prazosin approved for Insomnia / Sleep Disorders?
Prazosin has reached the approved stage (maximum clinical phase 4) for at least one indication, so its use in Insomnia / Sleep Disorders would be drug repurposing rather than first-in-human development. This does not mean it is approved for Insomnia / Sleep Disorders. Approval status for the specific indication should always be confirmed with the relevant regulator and prescribing information.
Is Prazosin in clinical trials for Insomnia / Sleep Disorders?
ClinicalTrials.gov lists 1 registered trial linking Prazosin to Insomnia / Sleep Disorders: 1 has completed. None of the registered studies carries a drug-development phase label, which is typical for behavioural, device and supplement protocols. It plans or enrolled 50 participants. Registered activity dates to 2006.
What does the evidence show for Prazosin in Insomnia / Sleep Disorders?
Prazosin has both completed registered trials and synthesis-level publications linked to Insomnia / Sleep Disorders. 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 ADCY2. 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 2026-07-05. Page built 2026-10-07.