Last reviewed 2026-04-20 · How we verify

Verapamil Hydrochloride

Calcium ion influx inhibitor that modulates ionic calcium across cell membranes of arterial smooth muscle and myocardial cells.

Verapamil hydrochloride is a calcium channel blocker indicated for angina (vasospastic, unstable, and chronic stable), arrhythmias (atrial flutter/fibrillation rate control and PSVT prophylaxis), and essential hypertension. The drug carries significant contraindications including severe left ventricular dysfunction, hypotension, sick sinus syndrome, and high-degree AV blocks, requiring careful patient selection. Major drug interactions exist with CYP3A4 inhibitors/inducers, statins (myopathy risk), and beta-blockers (additive cardiac effects), necessitating dose adjustments and monitoring. Verapamil remains an important therapeutic option when used appropriately with attention to contraindications and drug interactions.

At a glance

Mechanism of action

Verapamil hydrochloride exerts its pharmacologic effects by modulating the influx of ionic calcium across the cell membrane of arterial smooth muscle as well as in conductile and contractile myocardial cells. In angina, verapamil works through two mechanisms: relaxation and prevention of coronary artery spasm by dilating main coronary arteries and coronary arterioles, and reduction of oxygen utilization by decreasing total peripheral resistance and unloading the heart. In arrhythmias, electrical activity through the AV node depends significantly upon calcium influx through the slow channel; by decreasing this influx, verapamil prolongs the effective refractory period within the AV node and slows AV conduction.

Approved indications

• Angina at rest
• Chronic stable angina
• Arrhythmias
• Prophylaxis of paroxysmal supraventricular tachycardia
• Essential hypertension

Common side effects

• Hyperglycemia
• Covid-19
• Headache
• Upper Respiratory Infection
• Gastroenteritis
• Vomiting
• Viral Syndrome
• Sore Throat
• 2nd Degree Heart Block
• Cardiac Arrhythmia
• 1st Degree Heart Block
• Premature Ventricular Contractions

Drug interactions

• CYP3A4 inhibitors (erythromycin, ritonavir)
• CYP3A4 inducers (rifampin)
• HMG-CoA reductase inhibitors (simvastatin, lovastatin, atorvastatin)
• Aspirin
• Grapefruit juice
• Alcohol
• Beta-blockers

Key clinical trials

• Comparison of Intralesional Triamcinolone Acetonide Treatment With Intralesional Verapamil Hydrochloride in Keloids (NA)
• Pharmacokinetics and Safety of Commonly Used Drugs in Lactating Women and Breastfed Infants
• Treatment Effects of Bisoprolol and Verapamil in Symptomatic Patients With Non-obstructive Hypertrophic Cardiomyopathy (PHASE4)
• Hybrid Closed Loop Therapy and Verapamil for Beta Cell Preservation in New Onset Type 1 Diabetes (PHASE3)
• Fasting Study of Verapamil HCl Extended-Release Capsules 300 mg to Verelan® PM Extended-Release Capsules 300 mg (PHASE1)
• Food Study of Verapamil HCl Extended-Release Capsules 300 mg and Verelan® PM Extended-Release Capsules 300 mg (PHASE1)
• Fasting Applesauce Study of Verapamil HCl Extended-Release Capsules 300 mg and Verelan® PM Extended-Release Capsules 300 mg (PHASE1)
• Fasting Study of Verapamil HCl Extended-Release Capsules 300 mg and Verelan® PM Extended-Release Capsules 300 mg (PHASE1)

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.

Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

• Verapamil Hydrochloride CI brief — competitive landscape report
• Verapamil Hydrochloride updates RSS · CI watch RSS
• Pfizer Inc. portfolio CI