What is verapamil?
Verapamil is in a group of drugs called calcium channel blockers. It works by relaxing the muscles of your heart and blood vessels.
Verapamil is used to treat hypertension (high blood pressure), angina (chest pain), and certain heart rhythm disorders.
Verapamil may also be used for other purposes not listed in this medication guide.
You should not use this medication if you are allergic to verapamil, or if you have:
- certain serious heart conditions, especially "sick sinus syndrome" or "AV block" (unless you have a pacemaker);
- low blood pressure; or
- if you have recently had a heart attack.
If you have certain conditions, you may need a dose adjustment or special tests to safely use this medication. Before you take verapamil, tell your doctor if you have:
- kidney disease;
- liver disease;
- congestive heart failure; or
- a nerve-muscle disorder such as muscular dystrophy.
FDA pregnancy category C. It is not known whether verapamil is harmful to an unborn baby. Before taking this medication, tell your doctor if you are pregnant or plan to become pregnant during treatment.
Verapamil can pass into breast milk and may harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.
Verapamil can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert.
Avoid getting up too fast from a sitting or lying position, or you may feel dizzy. Get up slowly and steady yourself to prevent a fall.
Avoid drinking alcohol while taking verapamil.
Grapefruit and grapefruit juice may interact with verapamil and lead to potentially dangerous effects. Discuss the use of grapefruit products with your doctor. Do not increase or decrease the amount of grapefruit products in your diet without first talking to your doctor.
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Seek emergency medical attention if you think you have used too much of this medicine.
Overdose symptoms may include slow heartbeat and fainting.
Take the missed dose as soon as you remember. If it is almost time for your next dose, wait until then to take the medicine and skip the missed dose. Do not take extra medicine to make up the missed dose.
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Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have any of these serious side effects:
- fast or slow heartbeats;
- feeling like you might pass out;
- fever, sore throat, and headache with a severe blistering, peeling, and red skin rash;
- feeling short of breath, even with mild exertion;
- swelling, rapid weight gain; or
- nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).
Less serious side effects may include:
- constipation, nausea;
- skin rash or itching;
- dizziness, headache, tired feeling; or
- warmth, itching, redness, or tingly feeling under your skin.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
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Before taking verapamil, tell your doctor if you are using any of the following drugs:
- any other blood pressure medications;
- buspirone (BuSpar);
- carbamazepine (Carbatrol, Tegretol);
- cimetidine (Tagamet, Tagamet HB);
- cyclosporine (Gengraf, Neoral, Sandimmune);
- digoxin (digitalis, Lanoxin, Lanoxicaps);
- lithium (Eskalith, LithoBid);
- lovastatin (Mevacor);
- phenobarbital (Solfoton);
- rifampin (Rifadin, Rimactane, Rifater);
- theophylline (Elixophyllin, Theo-24, Uniphyl);
- a sedative such as midazolam (Versed) or triazolam (Halcion);
- an antibiotic such as clarithromycin (Biaxin), erythromycin (E-Mycin, E.E.S., Ery-Tab, Erythrocin), or telithromycin (Ketek);
- an antifungal medication such as fluconazole (Diflucan), itraconazole (Sporanox), ketoconazole (Nizoral), or voriconazole (Vfend);
- a beta-blocker such as atenolol (Tenormin), bisoprolol (Zebeta, Ziac), metoprolol (Lopressor, Toprol), propranolol (Inderal, InnoPran), sotalol (Betapace), timolol (Blocadren), and others;
- a heart rhythm medication such as amiodarone (Cordarone, Pacerone), disopyramide (Norpace), flecainide (Tambocor), or quinidine (Quinaglute, Quinidex, Quin-Release); or
- HIV/AIDS medicine such as amprenavir (Agenerase), atazanavir (Reyataz), delavirdine (Rescriptor), fosamprenavir (Lexiva), indinavir (Crixivan), nelfinavir (Viracept), or ritonavir (Norvir, Kaletra).
This list is not complete and there may be other drugs that can interact with verapamil. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.
Calan, Calan SR, Covera-HS, Isoptin, Isoptin I.V., Isoptin SR, Verelan, Verelan PM, and verapamil
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Copyright 1996-2004 Cerner Multum, Inc. Version 2.05. Revision date 8/23/04