Verapamil is used with or without other medications to treat high blood pressure (hypertension). Lowering high blood pressure helps prevent strokes, heart attacks, and kidney problems. Verapamil is called a calcium channel blocker. It works by relaxing blood vessels so blood can flow more easily. It may also lower the heart rate.
OTHER USES: This section contains uses of this drug that are not listed in the approved professional labeling for the drug but that may be prescribed by your health care professional. Use this drug for a condition that is listed in this section only if it has been so prescribed by your health care professional.
This drug may also be used to treat other heart diseases (such as hypertrophic cardiomyopathy, fast/irregular heartbeats) and to prevent chest pain (angina).
Take this medication by mouth with food, usually once daily in the morning or every 12 hours or as directed by your doctor.
Do not crush or chew extended-release tablets. Doing so can release all of the drug at once, increasing the risk of side effects. Also, do not split the tablets unless they have a score line and your doctor or pharmacist tells you to do so. Swallow the whole or split tablet without crushing or chewing.
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 time(s) each day.
For the treatment of high blood pressure, it may take a week before you get the full benefit of this drug. It is important to continue taking this medication even if you feel well. Most people with high blood pressure do not feel sick.
Do not suddenly stop taking this medication without consulting your doctor. Your condition may become worse when the drug is suddenly stopped. Your dose may need to be gradually decreased.
Tell your doctor if your condition does not improve or if it worsens (for example, your routine blood pressure readings remain high or increase).
Dizziness, slow heartbeat, constipation, nausea, headache, and tiredness may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.
To lower your risk of dizziness and lightheadedness, get up slowly when rising from a sitting or lying position.
Tell your doctor immediately if any of these unlikely but serious side effects occur: swelling ankles/feet, shortness of breath, unusual tiredness, unexplained/sudden weight gain, severe dizziness, fainting, very slow heartbeat.
Tell your doctor immediately if any of these rare but very serious side effects occur: severe stomach/abdominal pain, dark urine, yellowing eyes/skin, persistent nausea/vomiting.
In the US -
Before taking verapamil, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: certain types of heart rhythm problems (such as second- or third-degree atrioventricular block, sick sinus syndrome unless you have a pacemaker, Wolff-Parkinson-White syndrome, Lown-Ganong-Levine syndrome).
Before using this medication, tell your doctor or pharmacist your medical history, especially of: liver disease, kidney disease, heart failure, certain muscle/nerve disorders (muscular dystrophy, myasthenia gravis).
This drug may make you dizzy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Limit alcoholic beverages.
Before having surgery, tell your doctor or dentist that you are taking this medication.
Older adults may be more sensitive to the side effects of this drug, especially constipation, or swelling ankles/feet.
This medication passes into breast milk, but it is unlikely to harm a nursing infant. Discuss the risks and benefits with your doctor before breast-feeding.
Your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor or pharmacist first.
This drug should not be used with the following medication because very serious interactions may occur: dofetilide.
If you are currently using the medication listed above, tell your doctor or pharmacist before starting verapamil.
Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially of: aliskiren, clonidine, disopyramide, fingolimod, lithium.
Other medications can affect the removal of verapamil from your body, which may affect how this product works. Examples include atorvastatin, erythromycin, phenobarbital, rifamycins (such as rifampin), ritonavir, St. John's 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 buspirone, carbamazepine, colchicine, eplerenone, midazolam, certain drugs for organ transplant (cyclosporine, sirolimus, tacrolimus), certain "statin" drugs (lovastatin, simvastatin), temsirolimus, theophylline, tizanidine, triazolam, among others.
Check the labels on all your medicines (such as cough-and-cold products, diet aids, nonsteroidal anti-inflammatory drugs-NSAIDs such as ibuprofen for pain/fever reduction) because they may contain ingredients that could increase your blood pressure or heart rate. Ask your pharmacist about using those products safely.
If overdose is suspected, contact a poison control center or emergency room immediately. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: very slow heartbeat, severe dizziness, fainting.
Do not share this medication with others.
Talk with your doctor about making changes to your lifestyle that may help this medication work better (such as stress reduction programs, exercise, and dietary changes).
Laboratory and/or medical tests (such as liver function test) should be performed from time to time to monitor your progress or check for side effects. Consult your doctor for more details.
Have your blood pressure and pulse (heart rate) checked regularly while taking this medication. Learn how to check your own blood pressure and pulse at home, and share the results with your doctor.
There are different brands and types of this medication available. Some do not have the same effects. Do not change brands or types without consulting your doctor or pharmacist.
If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.
Store at room temperature between 59-77 degrees F (15-25 degrees C) away from light and moisture. Do not store in the bathroom. Keep all medicines away from children and pets.
MEDICAL ALERT: Your condition can cause complications in a medical emergency. For information about enrolling in MedicAlert, call 1-888-633-4298 (US) or 1-800-668-1507 (Canada).
Information last revised November 2013. Copyright(c) 2013 First Databank, Inc.
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