{"id":"placebo-to-prazosin","safety":{"commonSideEffects":[{"rate":"10-15","effect":"Dizziness"},{"rate":"8-12","effect":"Headache"},{"rate":"6-10","effect":"Fatigue"},{"rate":"5-8","effect":"Palpitations"},{"rate":"1-5","effect":"Syncope (first-dose effect)"}]},"_chembl":{"chemblId":"CHEMBL1558","moleculeType":"Small molecule","molecularWeight":"419.87"},"_sources":{"trials":{"url":"https://clinicaltrials.gov/search?intr=Placebo to Prazosin","method":"api_direct","source":"ClinicalTrials.gov","rawText":"","confidence":1,"sourceType":"ctgov","retrievedAt":"2026-04-20T06:19:02.599507+00:00"},"regulatory.ca":{"url":"","method":"api_direct","source":"Health Canada DPD","rawText":"","confidence":1,"sourceType":"health_canada_dpd","retrievedAt":"2026-04-20T06:19:09.998716+00:00"},"publicationCount":{"url":"https://pubmed.ncbi.nlm.nih.gov/?term=Placebo to Prazosin","method":"api_direct","source":"PubMed/NCBI","rawText":"","confidence":1,"sourceType":"pubmed","retrievedAt":"2026-04-20T06:19:10.587818+00:00"},"mechanism.target_chembl":{"url":"","method":"api_direct","source":"ChEMBL mechanism: Adrenergic receptor alpha-1 antagonist","rawText":"","confidence":1,"sourceType":"chembl","retrievedAt":"2026-04-20T06:19:11.360629+00:00"},"crossReferences.chemblId":{"url":"https://www.ebi.ac.uk/chembl/compound_report_card/CHEMBL1558/","method":"api_direct","source":"ChEMBL (EMBL-EBI)","rawText":"","confidence":1,"sourceType":"chembl","retrievedAt":"2026-04-20T06:19:11.273077+00:00"}},"_dailymed":null,"mechanism":{"_ai_source":"claude-haiku-4.5","explanation":"Prazosin selectively blocks alpha-1 adrenergic receptors on vascular smooth muscle and bladder tissue, causing vasodilation and reducing peripheral vascular resistance, which lowers blood pressure. It also relaxes smooth muscle in the prostate and bladder neck, improving urinary flow. The drug has also been used off-label for post-traumatic stress disorder (PTSD) nightmares, though the mechanism in this indication is not fully established.","oneSentence":"Prazosin is an alpha-1 adrenergic receptor antagonist that blocks norepinephrine signaling to reduce blood pressure and improve urinary symptoms.","_ai_confidence":"high"},"_scrapedAt":"2026-03-28T00:01:28.205Z","_scrapedBy":"cloudflare-swarm","_wikipedia":null,"_validation":{"fieldsValidated":0,"lastValidatedAt":"2026-04-20T06:19:13.036636+00:00","fieldsConflicting":0,"overallConfidence":0.95},"indications":{"approved":[{"name":"Hypertension"},{"name":"Benign prostatic hyperplasia (BPH)"},{"name":"PTSD-related nightmares (off-label)"}]},"trialDetails":[{"nctId":"NCT06629077","phase":"PHASE2","title":"Brain Blood Vessel Responses to Changes in Blood Flow","status":"RECRUITING","sponsor":"University of Wisconsin, Madison","startDate":"2026-02-26","conditions":"Magnetic Resonance Imaging, Cerebrovascular Circulation","enrollment":36},{"nctId":"NCT03539614","phase":"PHASE3","title":"Predicting Responses to PTSD Treatment With Iris and Cardiovascular Tests","status":"ACTIVE_NOT_RECRUITING","sponsor":"VA Office of Research and Development","startDate":"2018-06-04","conditions":"Posttraumatic Stress Disorder","enrollment":87},{"nctId":"NCT06629090","phase":"PHASE2","title":"Brain Blood Vessel Responses to Changes in Blood Flow: Younger Cohort","status":"RECRUITING","sponsor":"University of Wisconsin, Madison","startDate":"2025-12-17","conditions":"Magnetic Resonance Imaging, Cerebrovascular Circulation","enrollment":36},{"nctId":"NCT04793685","phase":"PHASE2","title":"Prazosin for Alcohol Use Disorder With Withdrawal Symptoms","status":"RECRUITING","sponsor":"Yale University","startDate":"2021-07-01","conditions":"Alcohol Withdrawal","enrollment":150},{"nctId":"NCT01437046","phase":"EARLY_PHASE1","title":"Doxazosin an a1 Antagonist for Alcohol Dependence","status":"COMPLETED","sponsor":"Brown University","startDate":"2011-11-01","conditions":"Alcohol Dependence, Anxiety","enrollment":41},{"nctId":"NCT05360953","phase":"PHASE2","title":"Treating Nightmares in Posttraumatic Stress Disorder With Clonidine and Doxazosin","status":"SUSPENDED","sponsor":"Charite University, Berlin, Germany","startDate":"2022-06-17","conditions":"Posttraumatic Stress Disorder","enrollment":53},{"nctId":"NCT03997864","phase":"PHASE4","title":"Administration of Prazosin to Prevent PTSD in Adult Women After Sexual Assault","status":"WITHDRAWN","sponsor":"University of Colorado, Denver","startDate":"2020-02-23","conditions":"Posttraumatic Stress Disorder","enrollment":""},{"nctId":"NCT02965027","phase":"PHASE4","title":"Prazosin for Post-Concussive Headaches","status":"COMPLETED","sponsor":"Seattle Institute for Biomedical and Clinical Research","startDate":"2016-11-29","conditions":"Post-Traumatic Headache","enrollment":89},{"nctId":"NCT02266329","phase":"PHASE1, PHASE2","title":"Chronic Postconcussive Headache: A Placebo-Controlled Treatment Trial of Prazosin","status":"COMPLETED","sponsor":"VA Office of Research and Development","startDate":"2016-01-04","conditions":"Posttraumatic Headache, Combat Disorders, Post Concussion Syndrome","enrollment":89},{"nctId":"NCT03339258","phase":"PHASE2","title":"A Randomized Controlled Trial of Doxazosin for Nightmares, Sleep Disturbance, and Non-Nightmare Clinical Symptoms in PTSD","status":"ACTIVE_NOT_RECRUITING","sponsor":"San Francisco Veterans Affairs Medical Center","startDate":"2018-04-15","conditions":"Stress Disorders, Post-Traumatic","enrollment":80},{"nctId":"NCT04108104","phase":"PHASE2","title":"Clinical Outcome of a Patented Pharmaceutical Composition (KT-110) to Treat Alcohol Use Disorder While Avoiding Major Side Effects","status":"COMPLETED","sponsor":"Kinnov Therapeutics","startDate":"2019-11-30","conditions":"Alcohol Use Disorder","enrollment":154},{"nctId":"NCT03221751","phase":"PHASE4","title":"Prazosin and Cerebrospinal Fluid (CSF) Biomarkers in Mild Traumatic Brain Injury (mTBI)","status":"TERMINATED","sponsor":"VA Office of Research and Development","startDate":"2016-12-01","conditions":"Dementia","enrollment":9},{"nctId":"NCT02616094","phase":"NA","title":"Multimodal Neuroimaging of Stress and Reward Cues to Assess Alcoholism Risk and Relapse","status":"COMPLETED","sponsor":"Yale University","startDate":"2015-11","conditions":"Alcohol Dependence","enrollment":224},{"nctId":"NCT03710642","phase":"PHASE2","title":"Prazosin for Agitation in Alzheimer's Disease","status":"COMPLETED","sponsor":"Alzheimer's Disease Cooperative Study (ADCS)","startDate":"2018-10-23","conditions":"Alzheimer's Disease, Disruptive Behavior","enrollment":35},{"nctId":"NCT02226367","phase":"NA","title":"Prazosin Augmentation of Outpatient Treatment of Alcohol Use Disorders in Active Duty Soldiers With and Without PTSD","status":"COMPLETED","sponsor":"Seattle Institute for Biomedical and Clinical Research","startDate":"2015-01","conditions":"Alcohol Use Disorders, Stress Disorders, Posttraumatic, Combat Disorders","enrollment":158},{"nctId":"NCT03398252","phase":"PHASE1","title":"Targeting Stress-Induced Alcohol Relapse Risk With Doxazosin XL","status":"WITHDRAWN","sponsor":"The University of Texas Health Science Center, Houston","startDate":"2022-05-12","conditions":"Alcohol Use Disorder","enrollment":""},{"nctId":"NCT02308202","phase":"PHASE1","title":"DOXAZOSIN FOR PTSD","status":"COMPLETED","sponsor":"Baylor College of Medicine","startDate":"2012-01","conditions":"PTSD","enrollment":30},{"nctId":"NCT02538744","phase":"PHASE1","title":"Complementary Combination Therapy for Cocaine Dependence","status":"COMPLETED","sponsor":"Baylor College of Medicine","startDate":"2015-08","conditions":"Cocaine Dependence","enrollment":45},{"nctId":"NCT02500602","phase":"PHASE2","title":"CAP: Doxazosin in the Treatment of Co-Occurring PTSD and Alcohol Use Disorders","status":"COMPLETED","sponsor":"VA Office of Research and Development","startDate":"2016-06-01","conditions":"Posttraumatic Stress Disorder, Alcohol Use Disorders","enrollment":144},{"nctId":"NCT02989493","phase":"PHASE2","title":"Testing Doxazosin to Treat Stress Mechanisms in Alcoholism","status":"COMPLETED","sponsor":"University of Wisconsin, Madison","startDate":"2017-04-12","conditions":"Alcoholism","enrollment":61},{"nctId":"NCT02322047","phase":"PHASE2","title":"Prazosin and Naltrexone (PaN) Study for Veterans With Alcohol Use Disorders","status":"COMPLETED","sponsor":"Seattle Institute for Biomedical and Clinical Research","startDate":"2015-03-03","conditions":"Alcohol Use Disorder, Posttraumatic Stress Disorder (PTSD)","enrollment":31},{"nctId":"NCT00585780","phase":"PHASE1, PHASE2","title":"Prazosin to Reduce Stress-Induced Alcohol/Drug Craving and Relapse","status":"COMPLETED","sponsor":"Yale University","startDate":"2009-09","conditions":"Alcohol Dependence","enrollment":100},{"nctId":"NCT04371757","phase":"NA","title":"Influence of the Autonomic Nervous System in Response to Exercise in Hypertensive Individuals","status":"UNKNOWN","sponsor":"Instituto de Cardiologia do Rio Grande do Sul","startDate":"2020-04-30","conditions":"Autonomic Nervous System, Hypertension","enrollment":39},{"nctId":"NCT02193256","phase":"EARLY_PHASE1","title":"Varenicline + Prazosin for Heavy Drinking Smokers","status":"COMPLETED","sponsor":"Yale University","startDate":"2014-07","conditions":"Cigarette Smoking, Alcohol Use Disorders","enrollment":5},{"nctId":"NCT01953432","phase":"PHASE2","title":"Pharmacogenetic Trial of Doxazosin for Treatment of Cocaine Abuse","status":"COMPLETED","sponsor":"VA Office of Research and Development","startDate":"2014-04-01","conditions":"Cocaine Dependence","enrollment":43},{"nctId":"NCT00880997","phase":"PHASE1","title":"The Efficacy of Doxazosin for Cocaine Users","status":"COMPLETED","sponsor":"Baylor College of Medicine","startDate":"2009-09","conditions":"Cocaine Dependence","enrollment":35},{"nctId":"NCT01145183","phase":"PHASE2","title":"Pharmacogenetics of Doxazosin for Cocaine Dependence","status":"COMPLETED","sponsor":"Baylor College of Medicine","startDate":"2010-03","conditions":"Cocaine Dependence","enrollment":96},{"nctId":"NCT02382848","phase":"NA","title":"Effectiveness of Prazosin in Bulimic Patients Experiencing Nightmares Due to PTSD","status":"COMPLETED","sponsor":"Milton S. Hershey Medical Center","startDate":"2015-07","conditions":"Stress Disorders, Post-Traumatic, Bulimia Nervosa","enrollment":9},{"nctId":"NCT02431936","phase":"PHASE2","title":"Effectiveness of Prazosin on the Urinary Sodium Excretion Response to Mental Stress","status":"COMPLETED","sponsor":"Augusta University","startDate":"2015-04","conditions":"Hypertension, Stress, Psychological, Blood Pressure","enrollment":50},{"nctId":"NCT00487032","phase":"PHASE4","title":"Differential Adrenoreceptor Mediated Tachyphylaxis and Upregulation","status":"COMPLETED","sponsor":"Brian J Lipworth","startDate":"2008-05","conditions":"Allergic Rhinitis, Tachyphylaxis, Rhinitis Medicamentosa","enrollment":19},{"nctId":"NCT01386177","phase":"PHASE1","title":"Pharmacological Interaction Between Doxazosin and Methylenedioxymethamphetamine (MDMA)","status":"COMPLETED","sponsor":"University Hospital, Basel, Switzerland","startDate":"2011-07","conditions":"Mood Disorder, Substance-Related Disorders, Amphetamine-Related Disorders","enrollment":16},{"nctId":"NCT00240227","phase":"NA","title":"Prazosin for ETOH or Cocaine Craving","status":"TERMINATED","sponsor":"US Department of Veterans Affairs","startDate":"2004-04","conditions":"Alcoholism, Cocaine Dependence","enrollment":8},{"nctId":"NCT00202449","phase":"NA","title":"Prazosin vs Paroxetine in Combat Stress-Related Post-Traumatic Stress Disorder (PTSD) Nightmares & Sleep Disturbance","status":"TERMINATED","sponsor":"Seattle Institute for Biomedical and Clinical Research","startDate":"2004-07","conditions":"Stress Disorders, Post-Traumatic, Sleep Disorders","enrollment":59},{"nctId":"NCT00183430","phase":"NA","title":"Prazosin for Treating Noncombat Trauma Post-Traumatic Stress Disorder","status":"TERMINATED","sponsor":"Seattle Institute for Biomedical and Clinical Research","startDate":"2003-10","conditions":"Post-Traumatic Stress Disorder, Sleep Initiation and Maintenance Disorders","enrollment":20},{"nctId":"NCT00990106","phase":"NA","title":"Augmentation Trial of Prazosin for Post-Traumatic Stress Disorder (PTSD)","status":"COMPLETED","sponsor":"Seattle Institute for Biomedical and Clinical Research","startDate":"2009-09","conditions":"Stress Disorders, Post-Traumatic, Combat Disorders, Sleep Disorders","enrollment":67},{"nctId":"NCT00532493","phase":"PHASE3","title":"Cooperative Studies Program #563 - Prazosin and Combat Trauma PTSD","status":"COMPLETED","sponsor":"VA Office of Research and Development","startDate":"2010-01-06","conditions":"PTSD, Sleep Disorders","enrollment":304},{"nctId":"NCT01916941","phase":"NA","title":"Neural Mechanisms of Change During the Treatment of Alcohol Use Disorders With Prazosin","status":"COMPLETED","sponsor":"University of New Mexico","startDate":"2013-09","conditions":"Alcohol Use Disorder","enrollment":36},{"nctId":"NCT01637584","phase":"NA","title":"Neurobiology of Sleep and Sleep Treatment Response in Returning Veterans","status":"COMPLETED","sponsor":"University of Pittsburgh","startDate":"2010-04","conditions":"Non PTSD, PTSD","enrollment":40},{"nctId":"NCT01178138","phase":"PHASE2","title":"Monoamine Antagonist Therapies for Methamphetamine Abuse Prazosin","status":"COMPLETED","sponsor":"University of Arkansas","startDate":"2009-12","conditions":"Continuous Methamphetamine Abuse","enrollment":24},{"nctId":"NCT00393874","phase":"NA","title":"Efficacy of Sleep Interventions for Posttraumatic Stress Disorder (PTSD)","status":"COMPLETED","sponsor":"University of Pittsburgh","startDate":"2006-10","conditions":"Anxiety Disorders, Mood Disorders, Insomnia","enrollment":50},{"nctId":"NCT01642433","phase":"PHASE2","title":"Prazosin for Smoking Cessation","status":"TERMINATED","sponsor":"Centre for Addiction and Mental Health","startDate":"2012-07","conditions":"Nicotine Dependence","enrollment":1},{"nctId":"NCT02266537","phase":"PHASE1","title":"Study to Assess the Influence of Three Different α-antagonists and Placebo on the Extent of Weekly Phenylephrine-induced Mydriasis at Three Different Concentrations of Phenylephrine in Healthy Male Volunteers","status":"COMPLETED","sponsor":"Boehringer Ingelheim","startDate":"2005-11","conditions":"Healthy","enrollment":97},{"nctId":"NCT00161473","phase":"NA","title":"Alzheimer's in Long-Term Care--Treatment for Agitation","status":"COMPLETED","sponsor":"University of Washington","startDate":"2001-01","conditions":"Alzheimer Disease, Psychomotor Agitation","enrollment":24},{"nctId":"NCT01062945","phase":"PHASE1","title":"The Effects of Doxazosin on the Cardiovascular and Subjective Effects of Cocaine","status":"COMPLETED","sponsor":"Baylor College of Medicine","startDate":"2010-01","conditions":"Cocaine Addiction, Cocaine Abuse, Cocaine Dependence","enrollment":13},{"nctId":"NCT01621165","phase":"NA","title":"Prazosin as an Antimanic Agent in Severe Mania or Mixed States","status":"WITHDRAWN","sponsor":"Mclean Hospital","startDate":"2009-03","conditions":"Bipolar, Mania, Bipolar, Mixed State","enrollment":""},{"nctId":"NCT00167687","phase":"PHASE4","title":"Prazosin Alcohol Dependence IVR Study","status":"COMPLETED","sponsor":"University of Washington","startDate":"2005-09","conditions":"Alcoholism","enrollment":23}],"_emaApprovals":[],"_faersSignals":[],"crossReferences":{"chemblId":"CHEMBL1558"},"_approvalHistory":[],"publicationCount":344,"rwe":[],"genericFilers":[],"relatedDrugs":[],"labelChanges":[],"biosimilarFilings":[],"pricing":[],"formularyStatus":[],"manufacturing":[],"companionDiagnostics":[],"competitors":[],"timeline":[],"patents":[],"ownershipHistory":[],"trials":[],"biosimilars":[],"latestUpdates":[],"references":[],"tags":[],"ecosystem":[],"genericManufacturerList":[],"offLabel":[],"developmentCodes":[],"aliases":[],"phase":"marketed","status":"active","brandName":"Placebo to Prazosin","genericName":"Placebo to Prazosin","companyName":"Brian J Lipworth","companyId":"brian-j-lipworth","modality":"Small molecule","firstApprovalDate":"","aiSummary":"Prazosin is an alpha-1 adrenergic receptor antagonist that blocks norepinephrine signaling to reduce blood pressure and improve urinary symptoms. Used for Hypertension, Benign prostatic hyperplasia (BPH), PTSD-related nightmares (off-label).","enrichmentLevel":3,"visitCount":0,"regulatoryByCountry":[{"country_code":"CA","regulator":"Health Canada","status":"approved","approval_date":null,"mah":"","brand_name_local":"","application_number":""},{"country_code":"US","regulator":"FDA","status":"approved","approval_date":null,"mah":null,"brand_name_local":null,"application_number":null}],"trialStats":{"total":0,"withResults":0},"validation":{"fieldsValidated":0,"lastValidatedAt":"2026-04-20T06:19:13.036636+00:00","fieldsConflicting":0,"overallConfidence":0.95},"verificationStatus":"verified","dataCompleteness":{"mechanism":true,"indications":true,"safety":true,"trials":true,"score":4}}