Calan (Verapamil)

What is this medicine?

Calan (Verapamil) is used to treat chest pain (angina), high blood pressure or irregular heartbeats.

Calan belongs to a class of medications, called calcium channel blockers. These medications block the movement of calcium into the muscle cells of the coronary arteries (the arteries supplying the heart) as well as the other arteries of the body. Since calcium is what triggers contraction of muscles, blocking entry of calcium relaxes the arterial muscles. This relaxation allows the arteries to become larger so that more blood can flow through them. Thus, calan is useful in treating and preventing chest pain (angina) resulting from spasm (contraction) of the coronary arteries that reduces the flow of blood to the heart. Relaxing the muscles lining the arteries in the rest of the body lowers blood pressure and thereby reduces the pressure against which the heart must pump blood. As a result, the heart works less and requires less oxygen-carrying blood. This allows the heart to work with the reduced flow of blood caused by coronary artery disease and prevents angina (which occurs whenever the flow of blood to the heart is inadequate). Calan also decreases the conduction of electrical impulses through the heart that control the coordination of contraction. As a result, the rate of contraction slows.

How should I take Calan?

This medication should be swallowed whole with a full glass of water unless your doctor directs you otherwise. This medication must be taken as directed to prevent chest pain. It is not effective if taken only when chest pain occurs. Do not stop taking this medication suddenly without your doctor's permission. Chest pain can occur if the medication is stopped too fast. Your dose may need to be gradually decreased.

What side effects may I notice from Calan?

This drug may cause dizziness and lightheadedness especially during the first few days. Avoid activities requiring alertness. When you sit or lie down for a while, get up slowly to allow your body to adjust and minimize dizziness. You may also experience weakness, fatigue, nausea, muscle cramps, headache, flushing or constipation. These effects should disappear as your body adjusts to the medication. Inform your doctor if they become bothersome. Notify your doctor immediately if you develop: breathing difficulties, swelling of the hands or feet, irregular heartbeat, fever, stomach/abdominal pain, yellowing eyes and skin, dark urine. If you notice other effects not listed above, contact your doctor or pharmacist.

More Information Calan

Laboratory tests (e.g., liver function tests) should be performed periodically to monitor for side effects. Do not share this medication with others.