Verapamil is in a group of drugs called calcium channel blockers. It works by relaxing the muscles of your heart and blood vessels.

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

Verapamil may also be used for other purposes not listed in this medication guide.

You should not use verapamil if you are allergic to it, or if you have certain serious heart conditions such as "sick sinus syndrome" or "AV block" (unless you have a pacemaker), low blood pressure, or if you have recently had a heart attack.

Before taking verapamil, tell your doctor if you are allergic to any drugs, or if you have kidney disease, liver disease, congestive heart failure, or a nerve-muscle disorder such as myasthenia gravis or muscular dystrophy.

There are many other drugs that can interact with verapamil. Tell your doctor about all medications you use. This includes prescription, over-the-counter, vitamin, and herbal products. Do not start a new medication without telling your doctor. Keep a list of all your medicines and show it to any healthcare provider who treats you.

Verapamil may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

Do not stop taking this medication without first talking to your doctor. If you stop taking verapamil suddenly, your condition may become worse.

Verapamil may be only part of a complete program of treatment that also includes diet, exercise, and other medications. Follow your diet, medication, and exercise routines very closely.

If you are being treated for high blood pressure, keep using this medication even if you feel well. High blood pressure often has no symptoms. You may need to use blood pressure medication for the rest of your life.

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

• certain serious heart conditions, especially "sick sinus syndrome" or "AV block" (unless you have a pacemaker);

• low blood pressure; or

• if you have recently had a heart attack.

To make sure you can safely take verapamil, tell your doctor if you have any of these other conditions:

• kidney disease;

• liver disease;

• congestive heart failure; or

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

FDA pregnancy category C. It is not known whether verapamil will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medication.

Verapamil can pass into breast milk and may harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.