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Verapamil Tablets

Verapamil is a calcium channel blocker that widens your blood vessels and relaxes your heart muscle. This improves blood flow to your heart and helps it pump more easily. Verapamil is for people with high blood pressure or angina (chest pain). Some people with irregular heart rhythms like SVT also take it.

Overview

What is this medication?

VERAPAMIL (ver AP a mil) treats high blood pressure and prevents chest pain (angina). It may also be used to treat a fast or irregular heartbeat (arrhythmia). It works by relaxing the blood vessels, which helps decrease the amount of work your heart has to do. It belongs to a group of medications called calcium channel blockers.

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This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.

COMMON BRAND NAME(S): Calan

What should I tell my care team before I take this medication?

They need to know if you have any of these conditions:

  • Duchenne muscular dystrophy
  • Heart disease
  • Irregular heartbeat or rhythm
  • Liver disease
  • Low blood pressure
  • An unusual or allergic reaction to verapamil, other medications, foods, dyes or preservatives
  • Pregnant or trying to get pregnant
  • Breast-feeding

How should I use this medication?

Take this medication by mouth. Take it as directed on the prescription label at the same time every day. You can take it with or without food. If it upsets your stomach, take it with food. Keep taking it unless your care team tells you to stop.

Do not take this medication with grapefruit juice.

Talk to your care team about the use of this medication in children. Special care may be needed.

Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.

NOTE: This medicine is only for you. Do not share this medicine with others.

What if I miss a dose?

If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.

What may interact with this medication?

Do not take this medication with any of the following:

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  • Cisapride
  • Disopyramide
  • Dofetilide
  • Grapefruit juice
  • Hawthorn
  • Pimozide
  • Red yeast rice

This medication may also interact with the following:

  • Barbiturates such as phenobarbital
  • Cimetidine
  • Cyclosporine
  • Lithium
  • Local anesthetics or general anesthetics
  • Medications for heart rhythm problems like amiodarone, digoxin, flecainide, procainamide, quinidine
  • Medications for high blood pressure or heart problems
  • Medications for seizures like carbamazepine and phenytoin
  • Rifampin, rifabutin or rifapentine
  • Theophylline or aminophylline

This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.

What should I watch for while using this medication?

Visit your care team for regular checks on your progress. Check your blood pressure as directed. Ask your care team what your blood pressure should be. Also, find out when you should contact them.

Do not treat yourself for coughs, colds, or pain while you are using this medication without asking your care team for advice. Some medications may increase your blood pressure.

You may get drowsy or dizzy. Do not drive, use machinery, or do anything that needs mental alertness until you know how this medication affects you. Do not stand up or sit up quickly, especially if you are an older patient. This reduces the risk of dizzy or fainting spells.

What side effects may I notice from receiving this medication?

Side effects that you should report to your care team as soon as possible:

  • Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
  • Heart failure—shortness of breath, swelling of the ankles, feet, or hands, sudden weight gain, unusual weakness or fatigue
  • Slow heartbeat—dizziness, feeling faint or lightheaded, trouble breathing, unusual weakness or fatigue
  • Liver injury—right upper belly pain, loss of appetite, nausea, light-colored stool, dark yellow or brown urine, yellowing skin or eyes, unusual weakness or fatigue
  • Low blood pressure—dizziness, feeling faint or lightheaded, blurry vision

Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome):

  • Constipation
  • Dizziness
  • Headache
  • Nausea

This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Where should I keep my medication?

Keep out of the reach of children and pets.

Store at room temperature between 20 and 25 degrees C (68 and 77 degrees F). Protect from light. Throw away any unused medication after the expiration date.

NOTE: This sheet is a summary. It may not cover all possible information. If you have questions about this medicine, talk to your doctor, pharmacist, or health care provider.

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Additional Common Questions

What does verapamil do?

Verapamil, a calcium channel blocker, helps your blood vessels widen more and your heart muscles relax. This makes it easier for your heart to pump blood. It brings your blood pressure down and slows your heart rate. When blood flow to your heart is better, it helps relieve angina (chest pain) and abnormal heart rhythms.

How long does verapamil stay in your system?

Verapamil has a half-life of four to seven hours (longer when you take it long term). This means that half of the dose is still in your system after that time. It can take more than 20 hours for a dose of verapamil to be out of your system.

Is verapamil a high-risk medication?

People who take high doses of verapamil, or who already have issues with their heart rhythm, can get heart rhythm problems like heart block or bradycardia. Nearly 2% of people taking verapamil experience heart failure or pulmonary edema, but it’s much more common to get constipation.

Your healthcare provider will weigh the risks and benefits of verapamil before prescribing it for you.

What should you avoid when taking verapamil?

You should avoid eating grapefruit or drinking its juice when taking verapamil. This fruit can worsen your side effects. It’s also a good idea to avoid taking St. John’s wort because it can change how verapamil works.

A note from Cleveland Clinic

Taking a medicine that’s new to you can make you feel uneasy. But your healthcare provider wouldn’t prescribe medication without considering the pros and cons of it first, along with your medical conditions. Don’t be afraid to ask questions about your medicine, including how it works and the best time of day to take it.

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Note: Introduction and Additional Common Questions written and medically approved by Cleveland Clinic professionals.

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