Verapamil is used to treat high blood pressure. Lowering high blood pressure helps prevent strokes, heart attacks, and kidney problems. Verapamil belongs to a class of drugs known as calcium channel blockers. It works by relaxing blood vessels so blood can flow more easily.
Verapamil is also used to prevent chest pain (angina). It may help to increase your ability to exercise and decrease how often you may get angina attacks. Verapamil is also used to control your heart rate if you have a fast/irregular heartbeat (such as atrial fibrillation). It helps to lower the heart rate, helping you to feel more comfortable and increase your ability to exercise.
Take this medication by mouth with or without food as directed by your doctor, usually 3 or 4 times daily.
The dosage is based on your medical condition and response to treatment.
Use this medication regularly to get the most benefit from it. To help you remember, take it at the same times each day.
For the treatment of high blood pressure, it may take a week before you get the full benefit of this drug. Keep taking this medication even if you feel well. Most people with high blood pressure do not feel sick.
To prevent chest pain, it is very important to take this medication regularly as prescribed. This drug should not be used to treat chest pain when it occurs. Use other medications to relieve sudden attacks as directed by your doctor (for example, nitroglycerin tablets placed under the tongue). Consult your doctor or pharmacist for details.
Do not stop taking this medication without consulting your doctor. Some conditions may become worse when this drug is suddenly stopped. Your dose may need to be gradually decreased.
Tell your doctor if your condition does not get better or if it gets worse (for example, your blood pressure readings remain high or increase or your chest pain occurs more often).
Dizziness, slow heartbeat, constipation, nausea, headache, or tiredness may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.Tell your doctor right away if you have any serious side effects, including: severe dizziness, fainting, new or worsening symptoms of heart failure (such as shortness of breath, swelling ankles/feet, unusual tiredness, unusual/sudden weight gain), very slow heartbeat.
This drug may rarely cause serious (possibly fatal) liver disease. Get medical help right away if you have any symptoms of liver damage, such as: nausea/vomiting that doesnt stop, loss of appetite, stomach/abdominal pain, yellowing eyes/skin, dark urine.
It should be stored at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.
Some products that may interact with this drug include: aliskiren, clonidine, disopyramide, dofetilide, dolasetron, fingolimod, lithium.
Other medications can affect the removal of verapamil from your body, which may affect how verapamil works. Examples include erythromycin, rifamycins (such as rifampin), ritonavir, St. Johns wort, among others.
Verapamil can slow down the removal of other medications from your body, which may affect how they work. Examples of affected drugs include asunaprevir, colchicine, flibanserin, ivabradine, lomitapide, midazolam, triazolam, among others.
Some products have ingredients that could raise your heart rate or blood pressure. Tell your pharmacist what products you are using, and ask how to use them safely (especially cough-and-cold products, diet aids, or NSAIDs such as ibuprofen/naproxen).
Symptoms of overdose may include:
slow, fast, or irregular heartbeat
difficulty breathing or swallowing. If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.