Verapamil (Calan SR) Uses

Calan SR (verapamil) is used to treat high blood pressure. It is also used to control angina (chest pain), including chronic stable angina, unstable angina, and vasospastic angina. Additionally, verapamil immediate-release tablets are used to treat arrhythmias (irregular heartbeats).

There may be other uses of verapamil—your pharmacist or doctor can give you further drug information.

Verapamil (Calan SR) Mechanism of Action

Verapamil acts on the heart and blood vessels directly. It relaxes the coronary arteries and eases blood flow, thereby improving cardiac contractility and lowering blood pressure. Verapamil also increases blood flow and oxygen supply to the heart, thus relieving angina. In addition, this drug helps to control heart rate by slowing electrical activity in the heart.

Verapamil (Calan SR) Doses

Verapamil is available as immediate release tablets (40 mg, 80 mg, and 120 mg) and sustained release tablets and capsules (120 mg, 180 mg, 240 mg, and 360 mg).

The usual dose of verapamil is as follows. Your doctor may recommend a dose reduction or dose escalation based on your response and tolerability (side effects).

For high blood pressure:

• Immediate-release tablets: Starting dose 80 mg three times a day. 
• Extended-release capsules: Starting dose 200 mg once daily at bedtime.
• Extended-release tablets: Starting dose 180 mg once daily in the morning.

For chest pain:

• Immediate-release tablets: 80 mg to 120 mg three times a day.
• Extended-release tablets: Starting dose 180 mg once daily at bedtime.

For heart rhythm problems:

• Immediate-release tablets: A total of 240 mg to 480 mg in 3-4 divided doses daily.

Note: Older adults and people with a low body weight may need to be started on lower initial doses.