Verapamil belongs to a class of medications called calcium-channel blockers. It works by relaxing the muscles of your heart and blood vessels so the heart does not have to pump as hard. Verapamil also increases the supply of blood and oxygen to the heart and slows electrical activity in the heart to control the heart rate.

Verapamil is used to treat hypertension (high blood pressure), angina (chest pain), and certain heart rhythm disorders.

The immediate-release tablets are also used alone or with other medications to prevent and treat irregular heartbeats.

Verapamil injection is used in adults and children to rapidly or temporarily restore normal heart rate in people with certain heart rhythm disorders.

High blood pressure is a common condition and when not treated, can cause damage to the brain, heart, blood vessels, kidneys and other parts of the body. Damage to these organs may cause heart disease, a heart attack, heart failure, stroke, kidney failure, loss of vision, and other problems. In addition to taking medication, making lifestyle changes will also help to control your blood pressure. These changes include eating a diet that is low in fat and salt, maintaining a healthy weight, exercising at least 30 minutes most days, not smoking, and using alcohol in moderation.

You should not use verapamil if you have a serious heart condition such as "sick sinus syndrome" or "AV block" (unless you have a pacemaker), severe heart failure, Wolff-Parkinson-White, Lown-Ganong-Levine syndrome, or slow heartbeats that have caused you to faint.

Tell your doctor what herbal products you are taking, especially St. John's wort.

Tell your doctor if you have or have ever had narrowing or blockage of your digestive system or any other condition that causes food to move through your digestive system more slowly; heart failure; heart, liver, or kidney disease; muscular dystrophy (inherited disease that causes gradual weakening of muscles); or myasthenia gravis (condition that causes certain muscles to weaken).

Talk to your doctor about the safe use of alcoholic beverages during your treatment. Verapamil may cause the effects of alcohol to be more severe and longer-lasting.

Verapamil comes as a tablet, an extended-release (long-acting) tablet, and an extended-release (long-acting) capsule to take by mouth. The regular tablet is usually taken three to four times a day. The extended-release tablets and capsules are usually taken once or twice a day. Take verapamil at around the same time(s) every day. Certain verapamil products should be taken in the morning and others at bedtime. Ask your doctor what the best time is for you to take your medication. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take verapamil exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Swallow the extended-release tablets and capsules whole. Do not chew or crush them. Ask your pharmacist if the tablets may be split in half, as the instructions vary by product.

If you can not swallow the extended-release capsules you may carefully open the capsule and sprinkle the entire contents onto a spoonful of applesauce. The applesauce should not be hot, and it should be soft enough to be swallowed without chewing. Swallow the applesauce immediately without chewing, and then drink a glass of cool water to make sure that you have swallowed all of the medicine. Do not store the mixture for future use.

Your doctor will probably start you on a low dose of verapamil and gradually increase your dose.

Verapamil controls arrhythmias, high blood pressure, and angina but does not cure these conditions. Continue to take verapamil even if you feel well. Do not stop taking verapamil without talking to your doctor.

Use verapamil exactly as prescribed by your doctor. Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose.

Verapamil injection is given into a vein by a healthcare provider. Your heart rate will be constantly monitored using an electrocardiogram or ECG (sometimes called an EKG). Your blood pressure and other vital signs will also be watched closely.

Verapamil oral is taken by mouth. Your pharmacist can provide more information about how to take the tablets or capsules.

Your dose needs may change if you switch to a different brand, strength, or form of this medicine.

Some forms of verapamil oral cannot be crushed or chewed, and some forms can be opened and mixed with applesauce. Ask your pharmacist how to take this medicine.

Your blood pressure and liver function will need to be checked often.

If you have high blood pressure, keep using this medicine even if you feel well. High blood pressure often has no symptoms.

Store at room temperature away from moisture, heat, and light.

You should not use verapamil if you are allergic to it, or if you have:

• "sick sinus syndrome" or "AV block" (unless you have a pacemaker);

• very low blood pressure; or

• if your heart cannot pump blood properly.

You may not be able to use verapamil if you have:

• severe congestive heart failure;

• certain heart rhythm disorders (such as 'Afib' or atrial flutter with Wolff-Parkinson-White syndrome or Lown-Ganong-Levine syndrome);

• a heart condition that causes you to have very rapid heartbeats; or

• if you are receiving an intravenous beta-blocker (such as atenolol, metoprolol, or propranolol).

To make sure verapamil is safe for you, tell your doctor if you have ever had:

• low blood pressure;

• abnormal thickening of the heart muscle;

• certain types of brain tumors;

• congestive heart failure;

• a nerve-muscle disorder such as myasthenia gravis or muscular dystrophy; or

• kidney or liver disease.

It is not known if verapamil will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

Do not breastfeed.

Verapamil injection is used when needed and does not have a daily dose. Call your doctor if the medicine is not effective.

Take verapamil oral as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not use two doses at one time.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An overdose can be fatal.

Overdose symptoms may include low blood pressure, slow heart rate, chest pain, shortness of breath, tiredness, high blood sugar, confusion, severe dizziness or fainting.

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

Talk to your doctor about eating grapefruit or drinking grapefruit juice while taking this medicine.

Avoid getting up too fast from a sitting or lying position, or you may feel dizzy. Avoid driving or hazardous activity until you know how this medicine will affect you. Your reactions could be impaired.

Grapefruit may interact with verapamil and cause side effects. Avoid consuming grapefruit products.

Drinking alcohol with this medicine can cause side effects.

Get emergency medical help if you have signs of an allergic reaction to verapamil: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Verapamil may cause serious side effects. Call your doctor at once if you have:

• chest pain, fast, slow, or uneven heart rate;

• a light-headed feeling, like you might pass out;

• heart problems - swelling, rapid weight gain, feeling short of breath;

• liver problems - loss of appetite, stomach pain (upper right side), tiredness, itching, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes); or

• fluid build-up in or around the lungs - pain when you breathe, feeling short of breath while lying down, wheezing, gasping for breath, cough with foamy mucus, cold, clammy skin, anxiety, rapid heartbeats.

Common verapamil side effects may include:

• nausea, constipation;

• infections, flu symptoms;

• swelling in lower legs or hands;

• headache, dizziness; or

• low blood pressure.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

If you also take disopyramide, avoid taking it within 48 hours before or 24 hours after you take verapamil.

Sometimes it is not safe to use certain medicines at the same time. Some drugs can affect your blood levels of other drugs you use, which may increase side effects or make the medicines less effective.

Many drugs can interact with verapamil. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here. Tell your doctor about all other medicines you use.

Keep all appointments with your doctor and the laboratory. Your blood pressure should be checked regularly to determine your response to verapamil. Your doctor may also order certain lab tests to check your body's response to verapamil.

If you are taking certain extended-release tablets (Covera HS), you may notice something that looks like a tablet in your stool. This is just the empty tablet shell, and this does not mean that you did not get your complete dose of medication.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

• Tarka® (containing trandolapril and verapamil)