Verapamil

What verapamil hydrochloride is and how it works

Verapamil is a calcium channel blocker that relaxes and widens blood vessels and slows electrical conduction in the heart. Oral verapamil is used long-term for high blood pressure and angina (chest pain). An intravenous form, given only by a healthcare professional, is used to quickly treat certain fast heart rhythms (supraventricular tachycardia and rapid atrial fibrillation/flutter). (1) (2)

If you take oral verapamil for blood pressure or angina, it is important your clinician knows about your heart function and any other heart medicines you take -- particularly beta-blockers -- because combining verapamil with a beta-blocker can slow your heart rate and conduction more than either medicine alone, which can be serious. Verapamil is not suitable for everyone, especially people with certain heart rhythm problems or significantly weakened heart pumping function.

Mechanism of action: how verapamil hydrochloride works

Verapamil is a phenylalkylamine calcium channel blocker that inhibits calcium ion influx through L-type calcium channels in cardiac and vascular smooth muscle, causing coronary and peripheral vasodilation, reduced myocardial contractility (negative inotropy), and slowed AV nodal conduction (negative dromotropy) -- the latter is the basis of its antiarrhythmic effect but also the mechanism behind its interaction risk with beta-blockers. (1) (2)

What verapamil hydrochloride is used for

Before taking verapamil hydrochloride

Do not take / not appropriate for

• Do not take/receive verapamil if you have severe left ventricular dysfunction (significantly weakened heart pumping function) -- verapamil's negative inotropic effect can worsen this. (all countries) (1) (2)
• Do not take/receive verapamil if you have cardiogenic shock, uncompensated heart failure, or low blood pressure (systolic below about 90 mmHg). (all countries) (1) (2)
• Do not take/receive verapamil if you have sick sinus syndrome or second- or third-degree AV block, unless you have a functioning artificial pacemaker. (all countries) (1) (2) (6)
• Do not take/receive verapamil if you have atrial flutter or fibrillation with an accessory conduction pathway (e.g. Wolff-Parkinson-White syndrome). (all countries) (1)
• Intravenous verapamil must not be given at the same time as an intravenous beta-blocker. (United Kingdom) (2)
• Intravenous verapamil should not be combined with ivabradine. (United Kingdom) (2)

Tell your clinician about

• Whether you take a beta-blocker (e.g. metoprolol, bisoprolol, propranolol) or any other heart-rate or blood-pressure medicine.
• Any history of heart failure, weakened heart pumping function, or slow/irregular heart rhythms.
• Whether you take digoxin, a statin (e.g. simvastatin, atorvastatin), or any medicine affecting liver enzymes (CYP3A4).
• Whether you are or could be pregnant, or are breastfeeding.
• Your age, especially if you are elderly or new to verapamil treatment, since a lower starting dose is often used.

How to take verapamil hydrochloride

• Oral extended-release verapamil is usually taken once daily in the morning with food, exactly as prescribed -- swallow extended-release tablets/capsules whole; do not crush or chew unless your product's labelling specifically allows it.
• Intravenous verapamil is given only by a healthcare professional as a slow injection over at least 2 minutes, with continuous heart-rhythm and blood-pressure monitoring.
• Do not stop oral verapamil suddenly or change your dose without talking to your prescriber.

Procedures and treatment changes

Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2) (3) (4) (5) (6)

Missed dose

If you miss a dose of oral verapamil, take it as soon as you remember unless it is almost time for your next dose -- in that case, skip the missed dose and continue your normal schedule. Do not take a double dose. If you are unsure, contact your pharmacist or prescriber. This does not apply to the intravenous form, which is scheduled and given entirely by your care team.

Overdose

An overdose of verapamil is a medical emergency -- seek immediate emergency medical attention. Signs can include severe low blood pressure, shock, a very slow or high-degree abnormal heart rhythm, or loss of consciousness. Treatment in hospital may include intravenous calcium, supportive care, atropine, or a temporary pacemaker. (2)

Side effects

Side effects and their urgency vary; report severe, persistent, or concerning symptoms.

Serious warnings

Interactions

• Beta-blockers (e.g. metoprolol, bisoprolol, propranolol): risk of excessive bradycardia, AV block, low blood pressure, and heart failure with additive cardiac depressant effects; intravenous verapamil with an intravenous beta-blocker is not given together. (1) (2)
• Digoxin: verapamil can raise digoxin blood levels by 50-75%, increasing the risk of digoxin toxicity -- your clinician may need to lower your digoxin dose and monitor levels. (1) (2)
• Certain statins (simvastatin, atorvastatin, lovastatin) and other medicines processed by the CYP3A4 liver enzyme can interact with verapamil -- dose adjustment may be needed. (2)
• Medicines that inhibit CYP3A4 can raise verapamil blood levels; medicines that induce CYP3A4 can lower them. (1)
• Ivabradine: combination with intravenous verapamil is avoided due to additive heart-rate-lowering effects. (2)

Pregnancy, breastfeeding, kidney/liver function, age

Monitoring

Before starting

• Baseline heart rate, blood pressure, and ECG, especially before intravenous use
• Assessment of left ventricular function
• Review of current medicines, especially beta-blockers and digoxin

During treatment

• Continuous ECG and blood pressure monitoring during and immediately after intravenous administration.
• Periodic monitoring of heart rate and blood pressure during oral treatment, especially at dose changes.
• Digoxin level monitoring if taken together with verapamil.
• Monitoring for signs of worsening heart failure, especially in patients with reduced heart function.

Storage

Store oral verapamil tablets/capsules at room temperature, away from moisture and light, as directed on the product label. Intravenous verapamil is stored and handled by healthcare professionals according to the product's labelling.

Frequently asked questions

References

1. VERAPAMIL HYDROCHLORIDE tablet, film coated, extended release -- prescribing informationU.S. Food and Drug Administration / DailyMed (NIH) · United States · accessed 2026-07-31 · source 1
2. Verapamil 2.5 mg/ml Solution for Injection -- Summary of Product Characteristicselectronic medicines compendium (emc), United Kingdom · United Kingdom · accessed 2026-07-31 · source 2
3. Verapamil -- list of nationally authorised medicinal products (PSUSA/00003105/202001)European Medicines Agency (EMA) -- list of nationally authorised medicinal products (PSUSA) · European Union · accessed 2026-07-31 · source 3
4. VERAPAMIL HYDROCHLORIDE INJECTION USP (DIN 02166739, Sandoz Canada) and multiple oral verapamil/verapamil SR productsHealth Canada Drug Product Database (live API query) · Canada · accessed 2026-07-31 · source 4
5. ISOPTIN and ANPEC verapamil hydrochloride products -- ARTG entries (e.g. 65502, 65503, 12796, 54032, 12801, 316008, 316009)Therapeutic Goods Administration (TGA), Australia -- Australian Register of Therapeutic Goods (ARTG) · Australia · accessed 2026-07-31 · source 5
6. ISOPTIN and ISOPTIN SR -- New Zealand Data Sheets (tablet and injection)Medsafe (New Zealand Medicines and Medical Devices Safety Authority) · New Zealand · accessed 2026-07-31 · source 6

Brand names by country

Single-ingredient verapamil hydrochloride names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.

Priority countries