Clinical Trials

Diphenhydramine has been evaluated across numerous clinical trials spanning Early Phase 1 through Phase 4 for conditions including allergic rhinitis, sleep disturbances following total joint arthroplasty, heat illness, and systemic lupus erythematosus. Sponsored by academic centers, government entities, and pharmaceutical companies such as Bayer, Genentech, the National Cancer Institute, and Lakehead University, these studies examine diverse therapeutic and thermoregulatory responses. Recruitment statuses for these trials range from completed and recruiting to terminated and withdrawn.

NCT Number Recruitment Conditions Sponsor/Collaborators Start Date Phases
NCT07709000 NOT_YET_RECRUITING
Chronic Lymphocytic Leukaemia; Small Lymphocytic Lymphoma; Hematologic Malignancies
Merck Sharp & Dohme LLC
 2026-09-11 PHASE2
NCT07570173 RECRUITING
B-cell Acute Lymphoblastic Leukemia
Merck Sharp & Dohme LLC
 2026-05-18 PHASE2; PHASE3
NCT07542756 RECRUITING
Insomnia; Insomnia Disorder; Chronic Insomnia; Chronic Insomnia Disorder
University of Pennsylvania
 2026-05-01 PHASE4
NCT04270409 ACTIVE_NOT_RECRUITING
Plasma Cell Myeloma
Sanofi
 2020-06-16 PHASE3
NCT05896228 RECRUITING
Refractory Multiple Myeloma; Relapsed Multiple Myeloma
Benjamin T Diamond, MD
 2024-02-20 PHASE2
NCT05977998 RECRUITING
Gastric Adenocarcinoma; Carcinomatosis
M.D. Anderson Cancer Center
 2023-09-08 PHASE2
NCT06043323 RECRUITING
Follicular Lymphoma
M.D. Anderson Cancer Center
 2024-01-08 PHASE2
NCT07472413 NOT_YET_RECRUITING
Multiple Sclerosis
University of Miami
 2026-09-01 PHASE3
NCT05039619 RECRUITING
Lupus Nephritis
Hoffmann-La Roche
 2022-05-12 PHASE2
NCT06207305 RECRUITING
Metastatic Appendiceal Adenocarcinoma; Intraperitoneal Paclitaxel
M.D. Anderson Cancer Center
 2024-01-30 PHASE1; PHASE2
NCT07358689 NOT_YET_RECRUITING
NSCLC
Tianjin Medical University Cancer Institute and Hospital
 2026-06-30 PHASE2
NCT05501678 RECRUITING
Autism; Autism Spectrum Disorder
Stanford University
 2023-08-09 PHASE2
NCT04224558 RECRUITING
Crohn Disease
Cedars-Sinai Medical Center
 2019-11-15 PHASE1; PHASE2
NCT06070649 RECRUITING
Alcohol Use Disorder (AUD); Alcohol-Related Disorders; Alcohol Use
Yale University
 2025-08-04 PHASE1
NCT06910241 RECRUITING
Laceration of Skin
Florida Atlantic University
 2025-09-03 PHASE3
NCT06702670 RECRUITING
Labor Dystocia
The University of Texas Health Science Center, Houston
 2025-03-25 PHASE2; PHASE3
NCT04268498 ACTIVE_NOT_RECRUITING
Multiple Myeloma
University of Miami
 2020-02-11 PHASE2
NCT07542730 RECRUITING
Pain; Abortion; Anxiety
University of Rochester
 2026-06-29 PHASE4
NCT06356571 RECRUITING
Plasma Cell Myeloma Refractory
Sanofi
 2025-03-17 PHASE2
NCT06704620 NOT_YET_RECRUITING
Advanced and Metastatic NSCLC
Tianjin Medical University Cancer Institute and Hospital
 2024-12 PHASE3
NCT00961792 ACTIVE_NOT_RECRUITING
Alcoholism
University of Chicago
 2004-03
NCT04862221 ACTIVE_NOT_RECRUITING
Acute Liver Failure; Fulminant Hepatic Failure; Hepatic Encephalopathy; Acute Liver Injury; Immune Dysregulation
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
 2022-02-09 PHASE2
NCT07285031 RECRUITING
Histamine; Exercise
University of British Columbia
 2025-12
NCT05285813 TERMINATED
AML; MDS
M.D. Anderson Cancer Center
 2022-05-06 PHASE2
NCT06083571 TERMINATED
Headache, Migraine
Washington University School of Medicine
 2024-01-01 PHASE2
NCT05704049 ACTIVE_NOT_RECRUITING
Relapsed/Refractory Multiple Myeloma
Sanofi
 2023-04-05 PHASE2
NCT04629248 ACTIVE_NOT_RECRUITING
Primary Membranous Nephropathy
Hoffmann-La Roche
 2021-06-25 PHASE3
NCT05298683 UNKNOWN
Multiple Myeloma; Renal Impairment; Neoplasms, Plasma Cell; Neoplasms by Histologic Type; Neoplasms; Paraproteinemias; Blood Protein Disorders; Hematologic Diseases
Hellenic Society of Hematology
 2022-05 PHASE2
NCT07778472 COMPLETED
Healthy
Palm Beach Atlantic University
 2025-02-24 EARLY_PHASE1
NCT03913559 TERMINATED
Acute Lymphoblastic Leukemia
St. Jude Children's Research Hospital
 2019-05-14 PHASE2
NCT04963296 ACTIVE_NOT_RECRUITING
Systemic Lupus Erythematosus
Hoffmann-La Roche
 2021-10-26 PHASE3
NCT05627557 ACTIVE_NOT_RECRUITING
Childhood Idiopathic Nephrotic Syndrome
Hoffmann-La Roche
 2023-03-29 PHASE3
NCT04681105 COMPLETED
Recurrent Acute Leukemia; Recurrent B Acute Lymphoblastic Leukemia; Recurrent Blastic Plasmacytoid Dendritic Cell Neoplasm; Recurrent Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Recurrent Hairy Cell Leukemia; Recurrent Hematologic Malignancy; Recurrent Hodgkin Lymphoma; Recurrent T Acute Lymphoblastic Leukemia; Refractory Acute Leukemia; Refractory B Acute Lymphoblastic Leukemia; Refractory Blastic Plasmacytoid Dendritic Cell Neoplasm; Refractory Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Refractory Hairy Cell Leukemia; Refractory Hematologic Malignancy; Refractory Hodgkin Lymphoma; Refractory T Acute Lymphoblastic Leukemia; Systemic Mastocytosis
City of Hope Medical Center
 2020-11-18 PHASE1
NCT04308837 UNKNOWN
Gastric Cancer; Stomach Cancer
Icahn School of Medicine at Mount Sinai
 2018-12-03 PHASE2
NCT06819774 RECRUITING
Acute Urticaria
Shandong New Time Pharmaceutical Co., LTD
 2024-04-22 PHASE3
NCT02858310 COMPLETED
Papillomavirus Infections; Cervical Intraepithelial Neoplasia; Carcinoma In Situ; Vulvar Neoplasms; Vulvar Diseases
National Cancer Institute (NCI)
 2017-01-27 PHASE1; PHASE2
NCT06182098 UNKNOWN
Migraine; Migraine in Children
Dayton Children's Hospital
 2023-06-27
NCT04165096 COMPLETED
Carcinoma, Non-Small-Cell Lung
Merck Sharp & Dohme LLC
 2020-01-21 PHASE2
NCT06345261 UNKNOWN
Catheter Complications
Cairo University
 2024-04-01
NCT05676216 UNKNOWN
Peripheral Vertigo
National Taiwan University Hospital
 2023-01-07
NCT02356159 COMPLETED
Myelodysplastic Syndromes; Hodgkin's Lymphoma; Non-Hodgkin's Lymphoma; Acute Leukemia; Multiple Myeloma
National Cancer Institute (NCI)
 2015-09-24 PHASE1; PHASE2
NCT05405166 ACTIVE_NOT_RECRUITING
Plasma Cell Myeloma Recurrent
Sanofi
 2022-06-23 PHASE3
NCT02681211 UNKNOWN
Migraine Headache
University of Louisville
 2016-02
NCT06019728 COMPLETED
Fabry's Disease
Sanofi
 2023-11-10 PHASE4
NCT03107182 COMPLETED
HPV-Related Squamous Cell Carcinoma; HNSCC
University of Chicago
 2017-06-27 PHASE2
NCT04221477 ACTIVE_NOT_RECRUITING
Lupus Nephritis
Hoffmann-La Roche
 2020-08-10 PHASE3
NCT03448393 COMPLETED
Lymphoma, Non-Hodgkin; Leukemia, Lymphocytic, B Cell; B-Cell Lymphoma; B-Cell Leukemia; Acute Lymphoid Leukemia; B-Non Hodgkin Lymphoma; B-NHL; B-All; Acute Lymphoblastic Leukemia; Acute Lymphocytic Leukemia
National Cancer Institute (NCI)
 2018-03-26 PHASE1
NCT04862585 COMPLETED
Anatomic Stage 0 Breast Cancer AJCC v8; Anatomic Stage I Breast Cancer AJCC v8; Anatomic Stage IA Breast Cancer AJCC v8; Anatomic Stage IB Breast Cancer AJCC v8; Anatomic Stage II Breast Cancer AJCC v8; Anatomic Stage IIA Breast Cancer AJCC v8; Anatomic Stage IIB Breast Cancer AJCC v8; Anatomic Stage III Breast Cancer AJCC v8; Anatomic Stage IIIA Breast Cancer AJCC v8; Anatomic Stage IIIB Breast Cancer AJCC v8; Anatomic Stage IIIC Breast Cancer AJCC v8; Anatomic Stage IV Breast Cancer AJCC v8; Breast Carcinoma; Prognostic Stage 0 Breast Cancer AJCC v8; Prognostic Stage I Breast Cancer AJCC v8; Prognostic Stage IA Breast Cancer AJCC v8; Prognostic Stage IB Breast Cancer AJCC v8; Prognostic Stage II Breast Cancer AJCC v8; Prognostic Stage IIA Breast Cancer AJCC v8; Prognostic Stage IIB Breast Cancer AJCC v8; Prognostic Stage III Breast Cancer AJCC v8; Prognostic Stage IIIA Breast Cancer AJCC v8; Prognostic Stage IIIB Breast Cancer AJCC v8; Prognostic Stage IIIC Breast Cancer AJCC v8; Prognostic Stage IV Breast Cancer AJCC v8
Ohio State University Comprehensive Cancer Center
 2021-10-07 PHASE2; PHASE3
NCT05211336 ACTIVE_NOT_RECRUITING
Primary Diffuse Large B-cell Lymphoma of the Central Nervous System (CNS); Aggressive B-cell Lymphoma With Secondary Involvement of the CNS
National Cancer Institute (NCI)
 2022-04-19 PHASE1
NCT06217367 UNKNOWN
Heat Illness; Allergic Rhinitis; Heat Injury; Sudomotor Sympathetic Dysfunction
Lakehead University
 2023-12-05 PHASE4
NCT02037126 COMPLETED
Cocaine-Related Disorders
University of Alabama at Birmingham
 2015-05 PHASE2
NCT04599634 COMPLETED
Follicular Lymphoma; Marginal Zone Lymphoma; Mantle Cell Lymphoma; Chronic Lymphocytic Lymphoma; B-Cell Lymphoma
National Cancer Institute (NCI)
 2021-12-16 PHASE1
NCT04109885 TERMINATED
Headache Disorders, Primary; Pain Management; Emergency Department
Christian Fromm, MD
 2020-09-15 PHASE2
NCT04918147 TERMINATED
IgG4 Related Disease; IgG4-RD
National Institute of Allergy and Infectious Diseases (NIAID)
 2021-10-13 PHASE2
NCT05013437 WITHDRAWN
Multiple Myeloma
Koen van Besien
 2023-09 EARLY_PHASE1
NCT05729555 UNKNOWN
Pain; Insomnia
Overseas Pharmaceuticals, Ltd.
 2023-04-03 PHASE1
NCT05648058 UNKNOWN
Nefopam
Ministry Of Health / Nineveh Health Directorate
 2022-12-20 PHASE3
NCT03030417 COMPLETED
Solid Tumors; Lymphoma
National Cancer Institute (NCI)
 2017-02-27 PHASE1
NCT04580121 COMPLETED
Acute Myeloid Leukemia
Hoffmann-La Roche
 2020-11-04 PHASE1
NCT02711826 COMPLETED
Kidney Transplant; Adult Living Donor Kidney Transplant Recipients; Renal Transplant; Living Kidney Donor
National Institute of Allergy and Infectious Diseases (NIAID)
 2016-09-20 PHASE1; PHASE2
NCT03805932 ACTIVE_NOT_RECRUITING
Hairy Cell Leukemia
National Cancer Institute (NCI)
 2019-10-03 PHASE1
NCT05586477 COMPLETED
Diphenhydramine Causing Adverse Effects in Therapeutic Use; Hyperthermia; Allergic Rhinitis; Sweating
Lakehead University
 2022-11-21 PHASE4
NCT03330028 COMPLETED
Diseases of Oesophagus Stomach and Duodenum
M.D. Anderson Cancer Center
 2017-10-27 PHASE1
NCT05674721 COMPLETED
Pain
HALEON
 2023-01-05 PHASE1
NCT06310642 COMPLETED
AMS; Acute Mountain Sickness
CHRISTUS Health
 2021-05-20 PHASE4
NCT05232825 COMPLETED
Relapsing Multiple Sclerosis; Primary Progressive Multiple Sclerosis
Hoffmann-La Roche
 2022-05-03 PHASE3
NCT05115136 UNKNOWN
Urticaria
State University of New York - Upstate Medical University
 2022-05-23 PHASE3
NCT05244460 UNKNOWN
Cannabis Hyperemesis Syndrome
Mercy Health Ohio
 2021-12-02 PHASE3
NCT05302388 COMPLETED
Asymptomatic Hyperuricemia
Shanghai Institute Of Biological Products
 2022-04-11 PHASE1
NCT01059786 ACTIVE_NOT_RECRUITING
Hairy Cell Leukemia
National Cancer Institute (NCI)
 2010-07-01 PHASE2
NCT04741139 UNKNOWN
Immune Thrombocytopenia
Baylor College of Medicine
 2021-09-02 PHASE1
NCT03324113 COMPLETED
Neoplasm Malignant
Sanofi
 2017-10-17 PHASE1
NCT05219604 TERMINATED
Central Nervous System Effects of Diphenhydramine; Pharmacokinetics of Diphenhydramine
Dent Neuroscience Research Center
 2022-03-15 PHASE4
NCT03554473 COMPLETED
Carcinoma, Small Cell; Lung Cancer; Small Cell Lung Cancer
National Cancer Institute (NCI)
 2018-09-11 PHASE1; PHASE2
NCT04660799 COMPLETED
Lymphoma, Large B-Cell, Diffuse
Hoffmann-La Roche
 2021-02-24 PHASE2
NCT04175834 COMPLETED
Multiple Sclerosis; Infusion Reaction
Providence Health & Services
 2020-02-05 PHASE3
NCT04294459 TERMINATED
Immune System Disorder
Sanofi
 2020-06-18 PHASE1; PHASE2
NCT05036174 UNKNOWN
Osteoarthritis
Federal State Budgetary Scientific Institution, Research Institute of Fundamental and Clinical Immunology
 2021-09
NCT03968939 COMPLETED
Primary Total Hip Arthroplasty; Primary Total Knee Arthroplasty
James A. Keeney
 2019-10-01 PHASE4
NCT04700007 COMPLETED
Itch
Aalborg University
 2021-01-18
NCT02867800 COMPLETED
Sickle Cell Disease; Graft Versus Host Disease
Monica Bhatia
 2016-07 PHASE1
NCT04840615 TERMINATED
Mesothelioma
National Cancer Institute (NCI)
 2021-06-11 PHASE1
NCT00324467 UNKNOWN
Lymphoma, Non-Hodgkin; Advanced Stage Diffuse Large B-Cell Non-Hodgkin's Lymphoma
British Columbia Cancer Agency
 2006-08 PHASE2
NCT04846348 TERMINATED
Cutaneous Mastocytoses
Joseph Butterfield
 2021-07-26 PHASE2
NCT02240407 COMPLETED
Pompe Disease
University of Florida
 2017-10-17 PHASE1
NCT02061293 COMPLETED
Alcohol Dependence
NYU Langone Health
 2014-06 PHASE2
NCT02495077 COMPLETED
Kidney Transplant
National Institute of Allergy and Infectious Diseases (NIAID)
 2015-11-02 PHASE2
NCT04189588 COMPLETED
Oncology Patients Receiving Chemotherapy
TerSera Therapeutics LLC
 2020-03-25 PHASE2
NCT04237090 COMPLETED
Breast Cancer; Lung Cancer; Ovarian Cancer; Oesophageal Cancer; Head Cancer Neck; Cervical Cancer; Endometrial Cancer
Ciusss de L'Est de l'Île de Montréal
 2020-02-14 PHASE3
NCT03220958 COMPLETED
Post-Traumatic Headache
Montefiore Medical Center
 2017-08-01 PHASE3
NCT04093271 COMPLETED
Sleep; Healthy
LifeSeasons Inc.
 2019-09-24 PHASE1
NCT02474199 COMPLETED
Liver Transplant Recipient; Living Donor (of the Respective Liver Transplant Recipient)
National Institute of Allergy and Infectious Diseases (NIAID)
 2016-06-06 PHASE1; PHASE2
NCT03490396 TERMINATED
Oral Mucositis
Midatech Pharma US Inc.
 2018-05-15 PHASE4
NCT02655354 COMPLETED
Posttraumatic Stress Disorder; Depression; Alcohol-Related Disorders; Suicidal Ideation; Substance-Related Disorders; Mild Cognitive Impairment; Quality of Life; Pain; Wounds and Injury; Brain Injuries; Chronic Disease
University of Washington
 2015-10
NCT02648490 COMPLETED
Solid Tumour
Henlix, Inc
 2016-09 PHASE1
NCT02188719 TERMINATED
Liver Transplantation
National Institute of Allergy and Infectious Diseases (NIAID)
 2014-12-17 PHASE1
NCT03185130 COMPLETED
Headache
University Medical Center of Southern Nevada
 2017-05-16 PHASE4
NCT02179814 SUSPENDED
Bulimia Nervosa; Eating Disorders; Dopamine; Reward; Catechol-O-methyltransferase
University of Bern
 2012-02-20
NCT03688464 WITHDRAWN
Atopic Dermatitis
University of Nebraska
 2019-02-02 EARLY_PHASE1
NCT01998971 COMPLETED
Multiple Myeloma
Janssen Research & Development, LLC
 2014-02-18 PHASE1
NCT03459612 COMPLETED
Healthy
Eli Lilly and Company
 2018-03-26 PHASE1
NCT01086540 COMPLETED
Systemic Sclerosis-Associated PAH
National Institute of Allergy and Infectious Diseases (NIAID)
 2011-06-24 PHASE2
NCT02935699 COMPLETED
Acute Urticaria
JDP Therapeutics, Inc.
 2017-03-01 PHASE3
NCT03424135 COMPLETED
Clinical Pharmacology
Bayer
 2018-03-02 PHASE1
NCT03396250 COMPLETED
Pain
Bayer
 2018-02-12 PHASE1
NCT03331042 COMPLETED
Transient Insomnia
Sequential Medicine Ltd
 2017-10-09 PHASE3
NCT02260934 COMPLETED
Lupus Nephritis
National Institute of Allergy and Infectious Diseases (NIAID)
 2015-07-09 PHASE2
NCT01967433 COMPLETED
Colonoscopy; Adjunct Anesthesia Medication
University of Oklahoma
 2013-12 PHASE4
NCT03142165 COMPLETED
Fibrosis
Bristol-Myers Squibb
 2017-05-11 PHASE1
NCT02999633 TERMINATED
T-cell Type Acute Leukemia-Precursor; T-lymphoblastic Lymphoma/Leukaemia
Sanofi
 2017-03-08 PHASE2
NCT02029638 TERMINATED
Kidney Transplantation
National Institute of Allergy and Infectious Diseases (NIAID)
 2014-01-07 PHASE2
NCT03056352 COMPLETED
Post-Traumatic Headache
Montefiore Medical Center
 2017-03-01 PHASE1; PHASE2
NCT02374567 TERMINATED
Dementia; Depression; Schizophrenia; Psychosomatic Disorders; Anxiety Disorders
Hannover Medical School
 2015-01 PHASE3
NCT02972502 TERMINATED
Headache, Migraine
OhioHealth
 2014-02 PHASE4
NCT02657031 COMPLETED
Headache
University Medical Center of Southern Nevada
 2016-03-17 PHASE4
NCT02339155 COMPLETED
Infections, Bacterial
Emergent BioSolutions
 2015-02-24 PHASE4
NCT00223691 COMPLETED
Autonomic Failure; Orthostatic Hypotension
Vanderbilt University
 2002-03 PHASE1
NCT02452528 TERMINATED
Chronic Hepatitis B
Arrowhead Pharmaceuticals
 2015-08 PHASE2
NCT02363946 TERMINATED
Alpha-1 Antitrypsin Deficiency
Arrowhead Pharmaceuticals
 2015-02 PHASE1
NCT01455389 TERMINATED
Lung Cancer
Genprex, Inc.
 2014-02 PHASE1; PHASE2
NCT02535416 COMPLETED
Healthy
Arrowhead Pharmaceuticals
 2015-09 PHASE1
NCT02389829 COMPLETED
Migraine
Montefiore Medical Center
 2015-03 PHASE4
NCT01968694 COMPLETED
Endometriosis
Brigham and Women's Hospital
 2010-12
NCT02229539 COMPLETED
Acute Oral Mucositis Pain
Alliance for Clinical Trials in Oncology
 2014-11-18 PHASE3
NCT02106325 COMPLETED
Depression
NYU Langone Health
 2013-12 PHASE2
NCT02441894 COMPLETED
Prostate Cancer
Sanofi
 2015-04 PHASE4
NCT02476058 COMPLETED
Major Depressive Disorder
Janssen-Cilag International NV
 2015-06-11 PHASE1
NCT01669967 COMPLETED
Neuropathic Pain
London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's
 2011-09
NCT01769586 COMPLETED
Sedation; Endoscopy
VA Connecticut Healthcare System
 2013-02
NCT01289938 TERMINATED
Drug Metabolism, Poor, CYP2D6-RELATED
Matthias Schwab
 2009-07 PHASE1
NCT02098499 WITHDRAWN
Migraine Headaches; Nausea; Restlessness
United States Naval Medical Center, Portsmouth
 2013-06-12 PHASE4
NCT01985126 COMPLETED
Multiple Myeloma
Janssen Research & Development, LLC
 2013-09-27 PHASE2
NCT02578186 COMPLETED
Occasional Sleeplessness
Procter and Gamble
 2013-11 PHASE4
NCT01825941 COMPLETED
Migraine
Montefiore Medical Center
 2013-04 PHASE4
NCT02023164 COMPLETED
Acute Urticaria
JDP Therapeutics, Inc.
 2013-07 PHASE3
NCT02142712 COMPLETED
Acute Cerebrovascular Accident; Cerebral Edema
University of Florida
 2014-12 PHASE2
NCT02295280 COMPLETED
Headache
St. Louis University
 2012-01
NCT01965301 TERMINATED
Healthy Male Volunteers
Bioprojet
 2014-10 PHASE1
NCT03435692 TERMINATED
Hip Surgery; Post Operative Pain Control
Seattle Children's Hospital
 2011-07-15
NCT02062710 COMPLETED
Cough Reflex Sensitivity
Montefiore Medical Center
 2014-01 PHASE4
NCT02463929 COMPLETED
Specified Sedative; Hypnotic
Universitas Diponegoro
 2014-04 PHASE4
NCT01985789 COMPLETED
Asthma
Don Cockcroft
 2013-11 PHASE4
NCT00899847 COMPLETED
Transplantation, Homologous; Transplantation, Autologous; Multiple Myeloma; Blood and Marrow Transplant (BMT)
Stanford University
 2009-05 PHASE2
NCT01888497 COMPLETED
Healthy
Pfizer's Upjohn has merged with Mylan to form Viatris Inc.
 2013-07-29 PHASE3
NCT00923910 COMPLETED
Leukemia, Acute Myelogenous (AML); Leukemia, Acute Lymphocytic (ALL); Leukemia, Chronic Myelogenous (CML); Myelodysplastic Syndrome (MDS); Non-Hodgkin's Lymphoma (NHL)
National Cancer Institute (NCI)
 2008-02-22 PHASE1; PHASE2
NCT00076752 COMPLETED
Lupus Erythematosus, Systemic
National Cancer Institute (NCI)
 2004-01-30 PHASE2
NCT01556932 COMPLETED
Nausea; Vomiting
Virginia Commonwealth University
 2012-03
NCT00515073 COMPLETED
Endometrial Cancer
M.D. Anderson Cancer Center
 2001-04 PHASE2
NCT01712828 COMPLETED
Healthy
Celgene
 2012-10-01 PHASE1
NCT01264939 COMPLETED
Chronic Idiopathic Urticaria
Genentech, Inc.
 2011-02 PHASE3
NCT01737931 COMPLETED
Healthy
Otsuka Pharmaceutical Co., Ltd.
 2012-08 PHASE1
NCT01011673 COMPLETED
Headache
Montefiore Medical Center
 2009-11 PHASE4
NCT01451762 COMPLETED
Surgery; Pain
Northwestern University
 2011-09
NCT00887640 TERMINATED
Prostate Cancer
Duke University
 2009-07 PHASE2
NCT01199497 WITHDRAWN
Nasal Congestion; Cough
Ache Laboratorios Farmaceuticos S.A.
 2011-08 PHASE3
NCT01837446 COMPLETED
Stomatitis
Isfahan University of Medical Sciences
 2011-07 PHASE2; PHASE3
NCT01406860 TERMINATED
Primary Headaches (Includes Migraines, Tension, Cluster Headaches)
University of Iowa
 2011-07
NCT00937924 COMPLETED
Endoscopic Ultrasound (EUS); Endoscopic Retrograde Cholangiopancreatography (ERCP)
University of California, Irvine
 2008-02 PHASE4
NCT01177852 WITHDRAWN
Inflammation; Cough; Rhinitis
Ache Laboratorios Farmaceuticos S.A.
 2011-10 PHASE3
NCT01067677 WITHDRAWN
Post Operative Nausea and Vomiting; Rescue Emetic Therapy
Franklyn Cladis
 2010-02
NCT01666678 COMPLETED
Therapeutic Equivalence
Bayer
 2012-01 PHASE1
NCT01495858 COMPLETED
Pain, Postoperative
Bayer
 2011-12 PHASE3
NCT01411124 COMPLETED
Restless Legs Syndrome (RLS)
XenoPort, Inc.
 2011-06 PHASE1
NCT01365052 COMPLETED
Pain
Bayer
 2011-05 PHASE3
NCT01321021 COMPLETED
Memory, Long-Term; Memory, Short-Term
Prof. Dominique de Quervain, MD
 2011-03
NCT01204255 COMPLETED
Healthy
Virginia Commonwealth University
 2010-11-15
NCT01280591 COMPLETED
Pain, Postoperative
Bayer
 2010-10 PHASE3
NCT01293968 COMPLETED
Aphthous Stomatitis
Qazvin University Of Medical Sciences
 2010-11 PHASE2
NCT00641797 COMPLETED
Benign Paroxysmal Positional Vertigo
Lehigh Valley Hospital
 2006-11
NCT00186628 COMPLETED
Leukemia, Mast-Cell; Mantle-cell Lymphoma
Stanford University
 2005-06 PHASE2
NCT00482053 TERMINATED
Lymphoma, B-cell; Lymphoma, Non-Hodgkin; Diffuse Large B-cell Lymphoma (DLBCL); Malignant Lymphoma, Non-Hodgkin
Stanford University
 2006-10 PHASE2
NCT00991809 COMPLETED
Hyperalgesia
Johns Hopkins University
 2009-02
NCT01017731 COMPLETED
Cancer; Solid Tumor
Eli Lilly and Company
 2009-11 PHASE2
NCT00490009 COMPLETED
Lymphoma
Susan Knox
 2004-09 PHASE2
NCT00638443 COMPLETED
Lumbar Spinal Stenosis
University of Rochester
 2008-03 PHASE4
NCT00682734 COMPLETED
Migraine
Montefiore Medical Center
 2008-04 PHASE3
NCT00078559 COMPLETED
Kidney Transplantation; Kidney Disease
University of Wisconsin, Madison
 2003-11 PHASE1; PHASE2
NCT00866788 COMPLETED
Chronic Idiopathic Urticaria
Genentech, Inc.
 2009-03 PHASE2
NCT00588159 COMPLETED
Pain
Michelle Kinney
 2007-06
NCT01858090 COMPLETED
Elective Caesarean Section Surgeries
Baskent University
 2009-01 PHASE3
NCT00837941 WITHDRAWN
Painful Diabetic Neuropathy
Merck Sharp & Dohme LLC
 2009-04 PHASE2
NCT00590590 COMPLETED
Vulvodynia
Lumara Health, Inc.
 2007-10 PHASE2
NCT00030992 COMPLETED
Renal Cell Carcinoma
National Cancer Institute (NCI)
 2002-02 PHASE2
NCT00282347 COMPLETED
Lupus Nephritis
Genentech, Inc.
 2006-01 PHASE3
NCT00762749 COMPLETED
Allergic Rhinitis
Johnson & Johnson Consumer and Personal Products Worldwide
 2008-09 PHASE1
NCT01119222 COMPLETED
Healthy
Pfizer
 2008-07 PHASE1
NCT00137969 COMPLETED
Lupus Erythematosus, Systemic
Genentech, Inc.
 2005-05-10 PHASE2; PHASE3
NCT00381810 TERMINATED
Lupus Erythematosus, Systemic
Genentech, Inc.
 2006-06-22 PHASE3
NCT01053338 COMPLETED
Healthy
Dr. Reddy's Laboratories Limited
 2008-04 PHASE1
NCT01053208 COMPLETED
Healthy
Dr. Reddy's Laboratories Limited
 2008-04 PHASE1
NCT00226941 TERMINATED
Rectal Cancer; Colo-rectal Cancer
George Albert Fisher
 2004-06 PHASE1; PHASE2
NCT01118273 COMPLETED
Sleep
Bayer
 2008-01 PHASE4
NCT00475306 COMPLETED
Nausea; Extrapyramidal Symptoms
Montefiore Medical Center
 2007-05 PHASE4
NCT01332318 COMPLETED
Restless Legs Syndrome
XenoPort, Inc.
 2007-04 PHASE2
NCT00648973 COMPLETED
Nasal Congestion
Johnson & Johnson Consumer and Personal Products Worldwide
 2006-11 PHASE4
NCT00662337 COMPLETED
Nasal Congestion
Johnson & Johnson Consumer and Personal Products Worldwide
 2006-10 PHASE1
NCT00137202 COMPLETED
Itching
United States Army Institute of Surgical Research
 2005-06
NCT00000875 TERMINATED
HIV Infections
National Institute of Allergy and Infectious Diseases (NIAID)
NCT00240123 WITHDRAWN
Gallbladder Disease; Gallstones; Pancreatitis; Abdominal Pain; Jaundice
University of Rochester
 2005-07 PHASE1

(data from https://clinicaltrials.gov, updated on 2026-08-27)

Check the Diphenhydramine product page for in-depth specifications, including solubility, stock solutions, MOA, and working concentrations.

Compliance for Clinical Use

Mechanism and Biochemical Profile

Diphenhydramine acts as a competitive antagonist of the histamine H1 receptor, preventing G-protein-coupled activation of phospholipase C and subsequent intracellular calcium release, which suppresses histamine-mediated vascular permeability and smooth muscle constriction. This targeted blockade directly alleviates symptomatic manifestations of allergic rhinitis and acute allergic reactions, while its central H1 receptor antagonism and anticholinergic activity underlie its therapeutic utility in managing sleep disturbances.

Appendix RUO and cGMP Quality Standards

Quality Dimension RUO (Research Use Only) cGMP (Current Good Manufacturing Practice)
Clinical Applicability Prohibited in human clinical trials or medical diagnostics. Mandatory for human clinical trials (Phase I–III) and therapies.
Regulatory Status Non-regulated grade; exempt from drug manufacturing laws. Legally enforced by health authorities (e.g., FDA, EMA, NMPA).
Facility Environment Unclassified analytical or research laboratories. Validated Cleanrooms (ISO Class 5–8) with continuous monitoring.
Quality Control Basic purity and activity testing. Rigorous safety release testing (Sterility, Endotoxin, Mycoplasma).
Process Validation Basic equipment calibration; no process validation required. Full qualification (IQ/OQ/PQ) and complete batch records.
Quality Assurance Vendor self-declared without required formal QMS. Mandatory QA/QC unit, Change Control, CAPA, and vendor audits.
Regulatory Impact High risk of IND rejection if used as a critical raw material. Required for IND/NDA filings, supported by Drug Master Files (DMF).

Footnotes

Regulatory Note: Governed by FDA (21 CFR Parts 210/211/312), EMA (EudraLex Vol 4), ICH Guidelines (E6/Q7/Q9/Q10), and compendial standards (USP <71>/<85>/<1043>).

Jump to

Note: Technical data last updated: Sep 1, 2026.