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Overview: Verapamil is taken for high blood pressure and to prevent chest pain or abnormal heart rhythms. Common side effects include headache and constipation. Serious side effects are rare, but can include low blood pressure or liver problems. Notify your healthcare provider right away if you have dizziness or feel lightheaded. Verapamil comes as a tablet and an extended-release tablet or capsule.

Uses

What is verapamil used for?

Verapamil is commonly used for the following conditions. 

Verapamil may also be used for other conditions as determined by your healthcare provider.

How does verapamil work (mechanism of action)?

Verapamil works by causing your blood vessels to relax and your heart to slow down. By relaxing the blood vessels, it makes it easier for blood to flow, which lowers blood pressure. This also means your heart does not have to work as hard, helping to prevent chest pain. By slowing the heart down, verapamil helps keep your heart rhythm normal. 

How is verapamil supplied (dosage forms)?

Brands and other names

  • Calan
  • Calan SR
  • Covera-HS
  • Isoptin
  • Isoptin SR
  • Verelan
  • Verelan PM

Dosage forms and strengths

  • 100 mg, 120 mg, 180 mg, 200 mg, 240 mg, 300 mg, 360 mg extended-release oral capsules
  • 120 mg, 180 mg, 240 mg extended-release oral tablets
  • 40 mg, 80 mg, 120 mg oral tablets

How should I store verapamil?

Verapamil should be stored at room temperature, between 68 F to 77 F (20 C to 25 C). It can be exposed to temperatures between 59 F to 86 F (15 C to 30 C) for shorter periods of time, such as when transporting it. Store in a cool, dry place. Protect verapamil from light and moisture.

Side Effects

What are the most common side effects of verapamil?

The most common side effects of verapamil are listed below. Tell your healthcare provider if you have any of these side effects that bother you.

  • Headache
  • Constipation
  • Low blood pressure (see below)
  • Swelling of your legs and ankles (edema)
  • Dizziness
  • Tiredness
  • Sore throat
  • Flu-like symptoms
  • Sinus swelling and pressure

There may be other side effects of verapamil that are not listed here. Contact your healthcare provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of verapamil?

While less common, the most serious side effects of verapamil are described below, along with what to do if they happen.

Low Blood Pressure (Hypotension). Verapamil may cause low blood pressure. If you feel faint or dizzy, lie down. Tell your healthcare provider right away if you have any of the following symptoms of low blood pressure.

  • Dizziness, feeling lightheaded, or fainting
  • Confusion
  • Feeling weak or tired

Liver Damage. Liver damage, also called hepatotoxicity, can happen when taking verapamil. Keep all appointments to have your blood checked. Call your healthcare provider right away if you have any of the following symptoms of liver damage.

  • Nausea or vomiting
  • Stomach or belly pain
  • Fever
  • Weakness or unusual tiredness
  • Itching
  • Loss of appetite
  • Light-colored poop
  • Dark-colored urine (pee)
  • Your skin or the whites of your eyes turning yellowish in color (also called jaundice)

Heart Rhythm Changes. Verapamil may cause heart rhythm problems that can lead to an irregular heartbeat and fainting. In rare cases, this may cause the heart to suddenly stop beating (cardiac arrest). Some people have a higher risk of this, including people with existing heart disease or who take other medicines that affect the heart. Get emergency help if you have any of the following signs of heart rhythm changes.

  • Chest pain
  • Shortness of breath
  • Feeling dizzy, lightheaded, or fainting
  • Changes in your heart rate or rhythm, such as a fast, slow, pounding or skipping heartbeat

Severe Allergic Reactions. Verapamil may cause allergic reactions, which can be serious. Stop taking verapamil and get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching, skin rash, or pale red bumps on the skin called hives
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain

Warnings & Precautions

Who should not use verapamil?

Allergies to Ingredients. People who are allergic to any of the following should not take verapamil.

  • Calan
  • Calan SR
  • Covera-HS
  • Isoptin
  • Isoptin SR
  • Verelan
  • Verelan PM
  • Verapamil
  • Any of the ingredients in the specific product dispensed

Your pharmacist can tell you all of the ingredients in the specific verapamil products they stock.

Severe Heart Failure. Verapamil should not be used if your heart failure is severe, causing you to feel very tired, have trouble breathing, or swelling in your legs. 

Low Blood Pressure (Hypotension). Verapamil should not be used if your blood pressure is too low. Your top number of your blood pressure measurement (systolic blood pressure) needs to be at least 90.

Cardiogenic Shock. Verapamil should not be used if you have a life-threatening condition called cardiogenic shock where your heart cannot pump enough blood to the rest of your body.

Heart Rhythm Problems. Verapamil should not be used if you have any of the following heart rhythm problems unless you have a working pacemaker.

Accessory Bypass Tract. Verapamil should not be used if you have atrial fibrillation or atrial flutter and an extra electrical pathway in the heart (accessory bypass tract), such as Wolff-Parkinson-White.

What should I know about verapamil before using it?

Do not take verapamil unless it has been prescribed to you by a healthcare provider. Take it as prescribed.

Do not share verapamil with other people, even if they have the same condition as you. It may harm them.

Keep verapamil out of the reach of children.

Verapamil can affect your alertness or coordination. Do not drive or do other activities that require alertness or coordination until you know how verapamil can affect you. 

Some verapamil tablets or capsules should be swallowed whole. Follow any instructions that come with your prescription. If you have trouble swallowing verapamil capsules, you can open up the capsules and pour the contents on a tablespoonful of applesauce. You should then swallow the applesauce right away without chewing it and drink a glass of water. Talk to your pharmacist if you have any questions about how to take your verapamil. 

If you are taking verapamil extended-release tablets, take each dose with food. 

People who are 65 or older can be at greater risk for some side effects from verapamil. Talk to your healthcare provider about your risks if you are in this age group.

What should I tell my healthcare provider before using verapamil?

Tell your healthcare provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them determine if verapamil is right for you.

In particular, make sure that you discuss any of the following.

Current and Past Health Conditions. Tell your healthcare provider if you have any of the following.

  • Heart problems, including heart failure, hypertrophic cardiomyopathy, or idiopathic hypertrophic subaortic stenosis
  • Liver problems
  • Kidney problems
  • Irregular heart rate or rhythm 
  • Nerve or muscle problems, such as myasthenia gravis or Duchenne’s muscular dystrophy

Other Medicines and Supplements. Verapamil may interact with other medicines and supplements. Before taking verapamil, tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

Pregnancy. It is not known if or how verapamil could affect pregnancy or harm an unborn baby. Tell your healthcare provider if you are or plan to become pregnant.

Breastfeeding. Verapamil passes into breast milk. Tell your healthcare provider if you are breastfeeding or plan to breastfeed. Your healthcare provider will advise you if you should stop breastfeeding or stop verapamil.

Interactions

Does verapamil interact with foods or drinks?

There are no known interactions between most verapamil products and foods or drinks. 

It is best to limit the amount of alcohol you drink. Verapamil may increase blood alcohol levels and make the effects of alcohol last longer. Also, your risk of dizziness and low blood pressure may be increased if you drink alcohol while taking verapamil.

Does verapamil interact with other medicines (drug interactions)?

Always tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. 

In particular, make sure you discuss if you are using any of the following before taking verapamil.

  • Erythromycin (Ery-Tab and others), which is a medicine used for bacterial infections
  • Ritonavir (Norvir), atazanavir (Reyataz), or nelfinavir (Viracept), which is a medicine commonly used to treat HIV
  • Rifampin, which is a medicine commonly used to treat an infection called tuberculosis
  • Ivabradine (Corlanor), which is a medicine for heart failure
  • A statin, such as atorvastatin (Lipitor and others), lovastatin, or simvastatin, which is a medicine to lower cholesterol
  • A beta-blocker, such as metoprolol (Lopressor, Toprol XL, and others), atenolol (Tenormin), or propranolol (Inderal LA, Innopran XL), which is a medicine that may be used for certain heart conditions or to reduce blood pressure
  • Digoxin (Lanoxin), which is a medicine used to treat irregular heartbeat and some types of heart failure
  • Clonidine (Catapres-TTS and others), which is a medicine used for high blood pressure or attention deficit hyperactivity disorder (ADHD)
  • A medicine for seizures, such as carbamazepine or phenobarbital
  • Aspirin, which is in many prescription and OTC products, including those for pain, swelling, and fever
  • Theophylline (Theo-24, Elixophyllin), which is a medicine for asthma or certain other breathing problems
  • Lithium, which is a medicine for certain mental health conditions
  • A medicine to treat cancer
  • A medicine that suppresses your immune system
  • A medicine used to control your heart rate or rhythm (antiarrhythmic)
  • A medicine for high blood pressure

Many other medicines may alter the blood levels of verapamil, and vice versa. Tell your healthcare provider about all medicines that you take or have recently taken.

This may not be a complete list of medicines that can interact with verapamil. Always check with your healthcare provider.

Does interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose/Missed Dose

What should I do if I accidentally use too much verapamil?

If you or someone else has used too much verapamil, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of verapamil?

If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and only take the next dose. Do not take double or extra doses.