Verapamil is called a calcium channel blocker. It works by relaxing blood vessels so blood can flow more easily.

Know the basics

What is verapamil used for?

Verapamil is used with or without other medications to treat high blood pressure (hypertension). Lowering high blood pressure helps prevent strokes, heart attacks, and kidney problems.

Verapamil is also used to prevent chest pain (angina). It may help to increase your ability to exercise and decrease how often you may get angina attacks. Verapamil is also used to control your heart rate if you have a fast or irregular heartbeat (such as atrial fibrillation). It helps to lower the heart rate, helping you to feel more comfortable and increase your ability to exercise.

This drug may also be used to treat another type of heart disease (hypertrophic cardiomyopathy).

How should I take verapamil?

Take this medication by mouth with or without food, usually 3 or 4 times daily or as directed by your doctor. Do not suddenly stop or withdraw treatment.

How do I store verapamil?

This product is best stored at room temperature away from direct light and moisture. To prevent drug damage, you should not store it in the bathroom or the freezer.

There may be different brands of this drug that may have different storage needs. So, it is important to always check the product package for instructions on storage, or ask your pharmacist. For safety, you should keep all medicines away from children and pets.

You should not flush this product down the toilet or pour them into a drain unless instructed to do so. Additionally, it is important to properly discard this product when it is expired or no longer needed. Consult your pharmacist for more details about how to safely discard your product.

Know the precautions & warnings

What should I know before using verapamil?

Before using this drug, tell your doctor if you are/have:

• Pregnant or breastfeeding.
• Taking any other medicines. This includes any prescription, OTC, and herbal remedies.
• An allergy to any of the ingredients of this product.
• Any other illnesses, disorders, or medical conditions.

Is it safe to take verapamil during pregnancy or breastfeeding?

Verapamil is a pregnancy category C drug. There are no adequate or well-controlled studies of verapamil in pregnant women. Verapamil distributes into breast milk. Due to the potential for adverse effects in nursing infants, discontinue breastfeeding during verapamil administration. Please always consult with your doctor to weigh the potential benefits and risks before taking this medication.

Know the side effects

What are the side effects of verapamil?

Like all drugs, this product may have side effects. If they occur, side effects are generally mild and resolve once treatment is finished or the dose is lowered. Some reported side effects include:

• AV block
• Slow heart rate (bradycardia)
• Hypotension
• Dizziness
• Flushing
• Fatigue
• Trouble breathing (dyspnea)
• Edema
• Constipation
• Nausea
• Abnormal liver function, jaundice
• Skin reactions or rash
• Gingival hyperplasia (enlarged gums)
• Tremors
• Gynecomastia

However, not everyone experiences these side effects. In addition, some people may experience other side effects. So, if you have any concerns about a side effect, please consult your doctor or pharmacist.

Know the interactions

What drugs may interact with verapamil?

This medication may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects.

To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs, and herbal products) and share it with your doctor and pharmacist.

Drugs with known interactions:

• Other antihypertensives (e.g. beta blockers, ARBs)
• Cimetidine
• Erythromycin
• Ritonavir
• Rifampicin
• Phenobarbital
• Aspirin, NSAIDs
• Telithromycin
• Clonidine
• Digoxin, digitoxin
• Prazosin, terazosin
• Immunosuppressants
• Statins
• Colchicine
• Quinidine
• Carbamazepine
• Imipramine
• Glibenclamide
• Doxorubicin
• Midazolam
• Buspirone
• Almotriptan
• Theophylline
• Diuretics
• Vasodilators
• Lithium

If you experience an adverse drug interaction, stop taking this drug and continue taking your other medication. Inform your doctor immediately to reevaluate your treatment plan. Approaches include dose adjustment, drug substitution, or ending therapy.

Does food or alcohol interact with verapamil?

Do not take this drug with alcohol, grapefruit juice, or St. John’s wort. These foods have known interactions with verapamil and should be avoided.

What health conditions may interact with verapamil?

This drug may interact with underlying conditions. This interaction may worsen your health condition or alter the way the drug works. Therefore, it is important to always let your doctor and pharmacist know all the health conditions you currently have, especially:

• Cardiogenic shock
• Congestive heart failure
• Enlarged heart (hypertrophic cardiomyopathy)
• AV block
• Sick sinus syndrome
• Ventricular dysfunction
• Atrial flutter or fibrillation
• Renal (kidney) impairment
• Hepatic (liver) impairment
• Neuromuscular disorders

Understand the dosage

The information provided is not a substitute for any medical advice. Therefore, you should always consult with your doctor or pharmacist before using any medication.

What is the dose for an adult?

Angina pectoris

Take 120 mg of verapamil three times a day. Up to 480 mg per day, for modified-release dosage forms.

Take 80 mg three times a day for angina associated with exertion or effort.

Supraventricular arrhythmias

Oral route: Take 120 to 480 mg per day, in three to four divided doses.

IV route: Start with 5 to 10 mg via slow injection over 2 to 3 minutes. Give another 5 mg after 5 to 10 minutes if needed.

Hypertension

Start with 240 mg per day, divided into two to three doses. Up to 480 mg per day.

Secondary prophylaxis of MI

Start with 360 mg per day in divided doses one week after an attack.

In case of hepatic impairment:

For severe impairment, reduce the normal dose by 60 to 70%.

What is the dose for a child?

Supraventricular arrhythmias

Oral route:

For 2 years and below: Give 20 mg of verapamil two to three times a day.

For older than 2 years: Give 40 to 120 mg two to three times a day.

IV route:

For 1 year and below: Give 0.1-0.2 mg/kg via slow drip over at least 2 minutes. Repeat after 30 minutes if necessary.

For 1 to 15 years: Give 0.1 to 0.3 mg/kg up to 5 mg per day via slow drip over at least 2 minutes. Repeat after 30 minutes if necessary.

Hypertension

For 2 years and below: Give 20 mg two to three times a day.

For older than 2 years: Give 40 to 120 mg two to three times a day.

In case of hepatic impairment:

For severe impairment, reduce the normal dose by 60 to 70%.

How is verapamil available?

Verapamil is available in the following dosage forms and strengths:

Tablet 40 mg, 80 mg, 180 mg, 240 mg

Solution for injection 5 mg/2 mL

What should I do in case of an emergency or overdose?

In case of an emergency or an overdose, call your local emergency services or go to the nearest emergency room.

What should I do if I miss a dose?

If you miss a dose, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and take your regular dose as scheduled. Do not take a double dose.