Clinical Trials

Numerous clinical trials evaluate the therapeutic efficacy of diltiazem across cardiovascular conditions—including hypertension, supraventricular tachycardia, atrial fibrillation, and coronary artery bypass graft recovery—and non-cardiovascular indications such as chronic anal fissure. Spanning Early Phase 1 through Phase 4, these completed, recruiting, active, withdrawn, and terminated protocols are supported by government agencies, academic research centers, and pharmaceutical sponsors. Notable efforts include evaluating oral post-surgical antispastic therapy, emergency management of supraventricular tachycardia, and pharmacokinetic drug-drug interaction profiles.

NCT Number Recruitment Conditions Sponsor/Collaborators Start Date Phases
NCT07456852 RECRUITING
Malignant Digestive System Neoplasm
Mayo Clinic
 2026-04-30 PHASE1; PHASE2
NCT06993038 RECRUITING
Supraventricular Tachycardia (SVT)
Anne E. Zepeski
 2025-08-01 PHASE4
NCT06276127 NOT_YET_RECRUITING
Atrial Fibrillation With Rapid Ventricular Response; Atrial Flutter With Rapid Ventricular Response
Oman Medical Speciality Board
 2025-04 PHASE3
NCT07697625 RECRUITING
Healthy
Merck Sharp & Dohme LLC
 2026-07-20 PHASE1
NCT07103655 NOT_YET_RECRUITING
Hypertrophic Cardiomyopathy (HCM)
Second Affiliated Hospital, Zhejiang University, School of Medicine
 2026-01-01 PHASE4
NCT04777045 ACTIVE_NOT_RECRUITING
Microvascular Angina; Coronary Vasospasm; Microvascular Ischemia of Myocardium
Radboud University Medical Center
 2019-10-25 PHASE3
NCT07232589 COMPLETED
Healthy
Merck Sharp & Dohme LLC
 2025-12-08 PHASE1
NCT07545187 COMPLETED
Surgical Site Infection Prevention; Episiotomy Infection; Episiotomy Wound; Normal Vaginal Delivery
Alaa Nadhim Hameed
 2025-06-01 PHASE1; PHASE2
NCT04153032 UNKNOWN
Anal Fissure
American University of Beirut Medical Center
 2019-12-01 PHASE2
NCT06818968 COMPLETED
Healthy
Merck Sharp & Dohme LLC
 2025-02-27 PHASE1
NCT07456423 COMPLETED
Supraventricular Tachycardia (SVT); Atrioventricular Nodal Re Entrant Tachycardia
Haseki Training and Research Hospital
 2024-07-01 PHASE4
NCT05691959 UNKNOWN
Atrial Fibrillation With Rapid Ventricular Response; Hypotension
Ascension Health
 2023-01-26 PHASE2
NCT05661942 COMPLETED
Atrial Fibrillation With Rapid Ventricular Response; Hypotension Drug-Induced
Wake Forest University Health Sciences
 2022-11-30 PHASE4
NCT06534671 COMPLETED
Jervell and Lange Nielsen Syndrome
Vanderbilt University Medical Center
 2024-10-16 PHASE4
NCT05563168 WITHDRAWN
COVID-19
Hospices Civils de Lyon
 2023-04 PHASE2
NCT06662396 COMPLETED
Healthy
Merck Sharp & Dohme LLC
 2024-06-13 PHASE1
NCT06554639 COMPLETED
Prostatic Neoplasms
Merck Sharp & Dohme LLC
 2024-07-11 PHASE1
NCT06494007 COMPLETED
Atrial Fibrillation; Rapid Ventricular Response; Hypotension Drug-Induced
Haseki Training and Research Hospital
 2023-01-01 PHASE4
NCT05294887 UNKNOWN
Coronary Microvascular Dysfunction; Microvascular Angina; Vasospasm, Coronary; Vasospastic Angina; Prinzmetal Angina; Coronary Artery Disease
Charite University, Berlin, Germany
 2022-03-04 PHASE4
NCT06692647 COMPLETED
Healthy; Pain
Merck Sharp & Dohme LLC
 2024-02-09 PHASE1
NCT06703463 COMPLETED
Healthy
Merck Sharp & Dohme LLC
 2023-10-17 PHASE1
NCT05745337 UNKNOWN
Atrial Fibrillation; Diastolic Dysfunction; HFpEF - Heart Failure With Preserved Ejection Fraction
University of Vermont
 2023-02-06 PHASE1
NCT04372082 WITHDRAWN
Sars-CoV2
University Hospital, Lille
 2020-05 PHASE3
NCT05391893 COMPLETED
Atrial Fibrillation; Atrial Flutter
Corewell Health South
 2020-06-19 PHASE4
NCT04310995 COMPLETED
Coronary Artery Bypass Graft; Radial Artery Grafts; Antispastic Therapy; Pilot Study
Ruijin Hospital
 2020-06-02 PHASE4
NCT05162222 COMPLETED
Healthy Participants
Bristol-Myers Squibb
 2021-12-15 PHASE1
NCT04513509 COMPLETED
Atrial Fibrillation; Rate Control; Cardiopulmonary Exercise Test
National Taiwan University Hospital
 2020-10-21
NCT05261464 UNKNOWN
Heart Rate; Coronary Computed Tomography Angiography
Mahidol University
 2021-01-30 PHASE4
NCT03212716 TERMINATED
Flu
University Hospital, Lille
 2017-12-23 PHASE2
NCT04130438 TERMINATED
Myocardial Bridging
Stanford University
 2020-10-15 PHASE2
NCT04551963 COMPLETED
B-cell Malignancies
BeiGene
 2020-11-15 PHASE1
NCT04276298 COMPLETED
Hemorrhoid Pain; Hemorrhoids
University of Auckland, New Zealand
 2020-09-01 PHASE2; PHASE3
NCT05950971 TERMINATED
Atrial Fibrillation New Onset; Atrial Fibrillation Paroxysmal
Seoul National University Hospital
 2021-07-01
NCT04790331 UNKNOWN
Verapamil; Diltiazim; FESS
Assiut University
 2021-03-01 EARLY_PHASE1
NCT04141553 UNKNOWN
Atrial Fibrillation; Atrial Flutter; Rapid Ventricular Response
Mercy Health Muskegon
 2019-12-01 PHASE4
NCT04887818 UNKNOWN
Fissure in Ano; Rectal Diseases; Rectal Bleed
University of Calgary
 2021-06 PHASE2; PHASE3
NCT02695992 COMPLETED
Atrial Fibrillation; Permanent Atrial Fibrillation
Asker & Baerum Hospital
 2016-02 PHASE4
NCT04154800 COMPLETED
Health Participants
Bristol-Myers Squibb
 2019-12-06 PHASE1
NCT03472495 COMPLETED
Atrial Fibrillation and Flutter
Virginia Commonwealth University
 2018-06-01 PHASE4
NCT03752931 UNKNOWN
Postoperative Cardiac Complication
Abderrahmane Mami Hospital
 2018-12 PHASE2
NCT03580590 UNKNOWN
Hypotension on Induction
Assiut University
 2018-09-01 EARLY_PHASE1
NCT03930433 COMPLETED
Coronary Vasospasm
Korea University Anam Hospital
 2018-01-01 PHASE4
NCT02025465 UNKNOWN
Atrial Fibrillation; Atrial Flutter
CAMC Health System
 2013-12 PHASE4
NCT02158013 TERMINATED
Chronic Anal Fissure
Bispebjerg Hospital
 2014-09-01
NCT03070470 COMPLETED
Drug-induced QT Prolongation; Pharmacokinetics; Pharmacodynamics
Food and Drug Administration (FDA)
 2017-03-14 PHASE1
NCT04017845 COMPLETED
Colorectal Neoplasms; Colorectal Cancer; Adenomatous Polyp of Colon
Lewai Sharki Abdulaziz, MSc PhD
 2015-04-01 EARLY_PHASE1
NCT00223717 COMPLETED
Hypertension
Vanderbilt University
 2001-01 PHASE1
NCT02801305 COMPLETED
Digital Ulcer of Scleroderma
Mohammad Ali Nazarinia
 2016-06 PHASE2
NCT02419534 UNKNOWN
Fissure in Ano
King Saud University
 2014-11 PHASE4
NCT02947711 COMPLETED
Healthy Subjects
Eisai Co., Ltd.
 2016-10 PHASE1
NCT02922452 COMPLETED
Ischemic Stroke
Bristol-Myers Squibb
 2016-09 PHASE1
NCT02807909 COMPLETED
Thrombosis
Bristol-Myers Squibb
 2016-07 PHASE1
NCT02479204 TERMINATED
Healthy Subjects
Viatris Innovation GmbH
 2015-04-28 PHASE1
NCT02653872 COMPLETED
Healthy Subjects
AstraZeneca
 2016-01-22 PHASE1
NCT02526888 COMPLETED
Healthy Subjects
Idorsia Pharmaceuticals Ltd.
 2015-09-01 PHASE1
NCT02024919 COMPLETED
Coronary Artery Ectasia
Ankara University
 2012-06
NCT02300259 COMPLETED
Healthy Volunteers
Eli Lilly and Company
 2014-11 PHASE1
NCT01162902 UNKNOWN
Stable Angina
Seoul National University Hospital
 2013-09 PHASE4
NCT02319148 COMPLETED
Healthy Volunteers
Pfizer
 2014-07 PHASE1
NCT01645826 WITHDRAWN
Idiopathic Pulmonary Arterial Hypertension; Primary Pulmonary Hypertension; Pulmonary Arterial Hypertension; Familial Primary Pulmonary Hypertension
University of South Florida
 2012-07
NCT02308748 COMPLETED
Drug-induced QT Prolongation; Pharmacokinetics; Pharmacodynamics
Food and Drug Administration (FDA)
 2014-05 PHASE1
NCT02010970 COMPLETED
Healthy Volunteers; Pharmacologic Action
AstraZeneca
 2013-12 PHASE1
NCT01690221 COMPLETED
Chronic Anal Fissures
Ventrus Biosciences, Inc
 2012-10 PHASE3
NCT02080780 COMPLETED
CLARITHROMYCIN/DILTIAZEM [VA Drug Interaction]
Ventrus Biosciences, Inc
 2013-09 PHASE1
NCT01852565 COMPLETED
Atherosclerosis
GlaxoSmithKline
 2013-05-14 PHASE1
NCT01821274 UNKNOWN
Skin Irritation
Ventrus Biosciences, Inc
 2013-03 PHASE1
NCT01816191 UNKNOWN
Adult Subjects With Anal Fissures.
Ventrus Biosciences, Inc
 2013-02 PHASE1
NCT01816529 UNKNOWN
Diltiazem Skin Sensitivity.
Ventrus Biosciences, Inc
 2013-03 PHASE1
NCT00319982 COMPLETED
Hypertrophic Cardiomyopathy
Brigham and Women's Hospital
 2006-01 PHASE2; PHASE3
NCT01408524 COMPLETED
Hypertension; Craniotomy
Mahidol University
 2010-02 PHASE1; PHASE2
NCT01549496 WITHDRAWN
Hepatitis C; Hypertension
Ottawa Hospital Research Institute
 2012-05 PHASE1
NCT01594619 COMPLETED
Drug Induced Constipation
AstraZeneca
 2012-05 PHASE1
NCT01217515 COMPLETED
Chronic Anal Fissure
S.L.A. Pharma AG
 2010-10 PHASE3
NCT01655303 COMPLETED
Rapid Ventricular Response Atrial Fibrillation
Tehran University of Medical Sciences
 2011-02 PHASE4
NCT01422382 COMPLETED
Healthy
Kowa Research Institute, Inc.
 2011-05 PHASE4
NCT01261156 COMPLETED
Healthy Subjects
Eisai Inc.
 2010-10 PHASE1
NCT01914926 COMPLETED
Heart Rate and Rhythm Disorders
Antonios Likourezos
 2009-06 PHASE4
NCT01211808 COMPLETED
Atrial Fibrillation
Bristol-Myers Squibb
 2010-09 PHASE1
NCT00313157 COMPLETED
Atrial Fibrillation
Asker & Baerum Hospital
 2006-04 PHASE3
NCT01151345 COMPLETED
Healthy
Pfizer
 2010-06 PHASE1
NCT01124760 COMPLETED
Pharmacokinetics
AstraZeneca
 2010-05 PHASE1
NCT00593463 COMPLETED
Drug Dependence
University of Arkansas
 2006-09 PHASE1
NCT01021176 TERMINATED
Food Intake
Pennington Biomedical Research Center
 2009-10 PHASE1
NCT00834925 UNKNOWN
Atrial Fibrillation
Seoul National University Hospital
 2009-08 PHASE4
NCT04222855 COMPLETED
Postpartum Preeclampsia
Hospital de la Mujer
 2009-01-01
NCT00712894 COMPLETED
Acute Myocardial Infarction; Percutaneous Coronary Intervention
Fudan University
 2006-12 PHASE4
NCT00713011 WITHDRAWN
Diabetic Nephropathies; Hypertension
Bayer
 2008-11 PHASE3
NCT02503865 COMPLETED
Metabolic Syndrome
Nazarbayev University
 2003-01 PHASE1; PHASE2
NCT00893100 COMPLETED
Pain
Tehran University of Medical Sciences
 2007-10 PHASE4
NCT00983372 COMPLETED
Healthy; Adult; Volunteer; Colchicine; Pharmacokinetics; Diltiazem; Cytochrome p450 3A4; P-glycoprotein
Mutual Pharmaceutical Company, Inc.
 2008-08 PHASE1
NCT01771978 UNKNOWN
Ischaemia-reperfusion Injury
University Hospital, Strasbourg, France
 2002-06 PHASE3
NCT00000478 COMPLETED
Cardiovascular Diseases; Coronary Disease; Heart Diseases; Myocardial Ischemia
National Heart, Lung, and Blood Institute (NHLBI)
 1990-11 PHASE3
NCT00000556 COMPLETED
Arrhythmia; Atrial Fibrillation; Cardiovascular Diseases; Heart Diseases
National Heart, Lung, and Blood Institute (NHLBI)
 1995-03 PHASE3
NCT00164801 TERMINATED
Non-Cardiac Chest Pain
Chinese University of Hong Kong
 2004-11
NCT00318201 COMPLETED
Healthy
Indiana University
 2006-04 PHASE4
NCT00039975 COMPLETED
HIV Infections; Cardiovascular Diseases; Hypertension
National Institute of Allergy and Infectious Diseases (NIAID)
 PHASE1
NCT00645463 COMPLETED
Obesity
Pfizer
 2007-03 PHASE1

(data from https://clinicaltrials.gov, updated on 2026-06-02)

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

Compliance for Clinical Use

Mechanism and Biochemical Profile

Diltiazem functions as a benzothiazepine calcium channel antagonist that selectively binds to CaV1.2 L-type calcium channels, thereby blocking transsarcolemmal L-type calcium currents in cardiac myocytes and vascular smooth muscle cells. This inhibition reduces intracellular calcium influx to suppress vascular tone and slow atrioventricular nodal conduction, translating clinically to blood pressure reduction and heart rate control in trial-evaluated conditions such as hypertension and supraventricular tachycardia.

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>).

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