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. Ask your pharmacist if the tablets may be split in half, because the directions depend on the product you take. 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.
Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
Tell your doctor right away 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 right away if any of these rare but very serious side effects occur: severe stomach/abdominal pain, dark urine, yellowing eyes/skin, persistent nausea/vomiting.
A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US -
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
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.
During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.
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.
Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.
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 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 asunaprevir, buspirone, carbamazepine, colchicine, ivabradine, midazolam, certain "statin" drugs (lovastatin, simvastatin), tacrolimus, temsirolimus, 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 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. 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 away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.
Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.
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 August 2016. Copyright(c) 2016 First Databank, Inc.
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