In this Article

• What is verapamil (Calan)?
• What are the possible side effects of verapamil?
• What is the most important information I should know about verapamil?
• What should I discuss with my healthcare provider before taking verapamil?
• How should I take verapamil?
• What happens if I miss a dose?
• What happens if I overdose?
• What should I avoid while taking verapamil?
• What other drugs will affect verapamil?
• Where can I get more information?

What should I discuss with my healthcare provider before taking verapamil?

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.

How should I take verapamil?

Take exactly as prescribed by your doctor. Do not take in larger or smaller amounts or for longer than recommended. Follow the directions on your prescription label.

Your doctor may occasionally change your dose to make sure you get the best results.

Do not crush, chew, break, or open an extended-release tablet or capsule. Swallow it whole. Breaking or opening the pill may cause too much of the drug to be released at one time.

If you have trouble swallowing a verapamil capsule whole, ask your doctor or pharmacist if it is safe for you to open the capsule and sprinkle the medicine into a spoonful of applesauce to make swallowing easier. Swallow this mixture right away without chewing. Do not save the mixture for later use. Discard the empty capsule.

Use verapamil regularly to get the most benefit. Get your prescription refilled before you run out of medicine completely.

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

If you are being treated for high blood pressure, keep using this medication even if you feel fine. High blood pressure often has no symptoms.

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.

Your blood pressure will need to be checked often. Your kidney or liver function may also need to be tested. Visit your doctor regularly.

If you need surgery, tell the surgeon ahead of time that you are using verapamil. You may need to stop using the medicine for a short time.

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