- What is verapamil, and how does it work (mechanism of action)?
- What brand names are available for verapamil?
- Is verapamil available as a generic drug?
- Do I need a prescription for verapamil?
- What are the side effects of verapamil?
- What is the dosage for verapamil?
- Which drugs or supplements interact with verapamil?
- Is verapamil safe to take if I'm pregnant or breastfeeding?
- What else should I know about verapamil?
What is verapamil, and how does it work (mechanism of action)?
Verapamil belongs to a class of medications called calcium channel blockers (CCBs), which includes amlodipine (Norvasc), diltiazem (Cardizem, Dilacor), nifedipine (Adalat, Procardia) as well as others. These medications block the movement of calcium into the muscle cells of the coronary arteries (the arteries supplying the heart with blood) as well as the other arteries of the body. Since calcium triggers contraction of muscles, blocking entry of calcium relaxes the muscles that surround the arteries. This relaxation allows arteries to become larger so that more blood can flow through them. Thus, verapamil 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 muscles in the arteries of 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). Verapamil also decreases the conduction of electrical impulses through the heart that control the coordination of contraction. As a result, the rate of contraction slows. Verapamil was approved by the FDA in March 1982.
What brand names are available for verapamil?
Calan, Verelan, Verelan PM,
Is verapamil available as a generic drug?
GENERIC AVAILABLE: Yes
Do I need a prescription for verapamil?
Yes
What are the side effects of verapamil?
Common side effects of Verapamil are
- dizziness,
- weakness or
- fainting because of a slow heart rate or low blood pressure.
Other side effects include
- swelling of the lower extremities,
- rash,
- headache,
- nausea, and
- constipation.
Verapamil also can cause mildly abnormal liver tests that usually return to normal with discontinuation of the medication. Verapamil may reduce heart rate. Verapamil also can cause excessive lowering of blood pressure in rare instances. Verapamil can aggravate heart failure, especially in patients with poor function of their heart muscle.
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Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.











