Isoptin SR

Generic Name: verapamil (oral) (ver AP a mil)

Brand Names: Calan, Calan SR, Covera-HS, Isoptin SR, Verelan, Verelan PM

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.

What is the most important information I should know about verapamil?

You should not use verapamil if you are allergic to it, or if you have certain serious heart conditions such as "sick sinus syndrome" or "AV block" (unless you have a pacemaker), low blood pressure, or if you have recently had a heart attack.

Before taking verapamil, tell your doctor if you are allergic to any drugs, or if you have kidney disease, liver disease, congestive heart failure, or a nerve-muscle disorder such as myasthenia gravis or muscular dystrophy.

There are many other drugs that can interact with verapamil. Tell your doctor about all medications you use. This includes prescription, over-the-counter, vitamin, and herbal products. Do not start a new medication without telling your doctor. Keep a list of all your medicines and show it to any healthcare provider who treats you. Verapamil may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert. Do not stop taking this medication without first talking to your doctor. If you stop taking verapamil suddenly, your condition may become worse.

Verapamil may be only part of a complete program of treatment that also includes diet, exercise, and other medications. Follow your diet, medication, and exercise routines very closely.

If you are being treated for high blood pressure, keep using this medication even if you feel well. High blood pressure often has no symptoms. You may need to use blood pressure medication for the rest of your life.

What should I discuss with my healthcare provider before taking verapamil?

You should not use verapamil if you are allergic to it, or if you have:

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  certain serious heart conditions, especially "sick sinus syndrome" or "AV block" (unless you have a pacemaker);

  
  


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  low blood pressure; or

  
  


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  if you have recently had a heart attack.

  
  

To make sure you can safely take verapamil, tell your doctor if you have any of these other conditions:

• kidney disease;


• liver disease;


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  congestive heart failure; or

  
  


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  a nerve-muscle disorder such as myasthenia gravis or muscular dystrophy.

  
  

FDA pregnancy category C. It is not known whether verapamil will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medication. 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.

How should I take verapamil?

Take exactly as prescribed by your doctor. Do not take in larger or smaller amounts or for longer than recommended. Follow the directions on your prescription label.

Your doctor may occasionally change your dose to make sure you get the best results.

Do not crush, chew, break, or open an extended-release tablet or capsule. Swallow it whole. Breaking or opening the pill may cause too much of the drug to be released at one time.

If you have trouble swallowing a verapamil capsule whole, ask your doctor or pharmacist if it is safe for you to open the capsule and sprinkle the medicine into a spoonful of applesauce to make swallowing easier. Swallow this mixture right away without chewing. Do not save the mixture for later use. Discard the empty capsule.

Use verapamil regularly to get the most benefit. Get your prescription refilled before you run out of medicine completely.

Do not stop taking this medication without first talking to your doctor. If you stop taking verapamil suddenly, your condition may become worse.

If you are being treated for high blood pressure, keep using this medication even if you feel fine. High blood pressure often has no symptoms.

Verapamil may be only part of a complete program of treatment that also includes diet, exercise, and other medications. Follow your diet, medication, and exercise routines very closely.

Your blood pressure will need to be checked often. Your kidney or liver function may also need to be tested. Visit your doctor regularly.

If you need surgery, tell the surgeon ahead of time that you are using verapamil. You may need to stop using the medicine for a short time. Store at room temperature away from moisture, heat, and light.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An overdose of verapamil can be fatal.

Overdose symptoms may include slow heartbeat and fainting.

What should I avoid while taking verapamil?

Verapamil may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be 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.

Drinking alcohol can further lower your blood pressure and may increase certain side effects of verapamil.

Grapefruit and grapefruit juice may interact with verapamil and lead to potentially dangerous effects. Discuss the use of grapefruit products with your doctor.

Verapamil side effects

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:

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  fast or slow heartbeats;

  
  


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  feeling like you might pass out;

  
  


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  fever, sore throat, and headache with a severe blistering, peeling, and red skin rash;

  
  


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  restless muscle movements in your eyes, tongue, jaw, or neck;

  
  


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  feeling short of breath, even with mild exertion;

  
  


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  swelling, rapid weight gain; or

  
  


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  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:

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  constipation, nausea;

  
  


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  skin rash or itching;

  
  


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  dizziness, headache, tired feeling; or

  
  


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  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.

What other drugs will affect verapamil?

Many drugs can interact with verapamil. Below is just a partial list. Tell your doctor if you are using:

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  buspirone (BuSpar);

  
  


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  cimetidine (Tagamet);

  
  


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  clonidine (Catapres, Clorpres, Kapvay, Nexiclon) or any other blood pressure medications;

  
  


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  cyclosporine (Gengraf, Neoral, Sandimmune);

  
  


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  digoxin (digitalis, Lanoxin, Lanoxicaps);

  
  


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  lithium (Eskalith, LithoBid);

  
  


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  lovastatin (Mevacor, Advicor) or simvastatin (Zocor, Simcor, Vytorin);

  
  


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  theophylline (Elixophyllin, Theo-24, Uniphyl);

  
  


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  an antibiotic such as clarithromycin (Biaxin), erythromycin (E.E.S., EryPed, Ery-Tab, Erythrocin, Pediazole), rifampin (Rifadin, Rimactane, Rifater), or telithromycin (Ketek);

  
  


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  an antifungal medication such as fluconazole (Diflucan), itraconazole (Sporanox), ketoconazole (Nizoral), or voriconazole (Vfend);

  
  


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  a beta-blocker such as atenolol (Tenormin), bisoprolol (Zebeta, Ziac), metoprolol (Lopressor, Toprol), propranolol (Inderal, InnoPran), sotalol (Betapace), timolol (Blocadren), and others;

  
  


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  cancer medicine such as cisplatin (Platinol), cyclophosphamide (Cytoxan, Neosar), doxorubicin (Adriamycin), paclitaxel (Taxol), procarbazine (Matulane), vincristine (Oncovin), or vinorelbine (Navelbine);

  
  


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  cholesterol-lowering drugs such as atorvastatin (Lipitor, Caduet), lovastatin (Mevacor, Altoprev, Advicor), or simvastatin (Zocor, Simcor, Vytorin, Juvisync);

  
  


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  a heart rhythm medication such as amiodarone (Cordarone, Pacerone), disopyramide (Norpace), flecainide (Tambocor), or quinidine (Quin-G);

  
  


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  HIV/AIDS medicine such as atazanavir (Reyataz), delavirdine (Rescriptor), fosamprenavir (Lexiva), indinavir (Crixivan), nelfinavir (Viracept), or ritonavir (Norvir, Kaletra);

  
  


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  a sedative such as midazolam (Versed) or triazolam (Halcion); or

  
  


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  seizure medication such as carbamazepine (Carbatrol, Equetro, Tegretol) or phenobarbital (Solfoton).

  
  

This list is not complete and other drugs may interact with verapamil. Tell your doctor about all medications you use. This includes prescription, over-the-counter, vitamin, and herbal products. Do not start a new medication without telling your doctor.

More Isoptin SR resources

• Isoptin SR Side Effects (in more detail)
• Isoptin SR Use in Pregnancy & Breastfeeding
• Drug Images
• Isoptin SR Drug Interactions
• Isoptin SR Support Group
• 0 Reviews for Isoptin SR - Add your own review/rating

• Isoptin SR Advanced Consumer (Micromedex) - Includes Dosage Information


• Isoptin SR Controlled-Release Tablets MedFacts Consumer Leaflet (Wolters Kluwer)


• Isoptin SR Prescribing Information (FDA)


• Verapamil Prescribing Information (FDA)


• Calan Prescribing Information (FDA)


• Calan MedFacts Consumer Leaflet (Wolters Kluwer)


• Calan SR Prescribing Information (FDA)


• Covera-HS Sustained-Release Tablets (Controlled Onset) MedFacts Consumer Leaflet (Wolters Kluwer)


• Covera-HS Prescribing Information (FDA)


• Verapamil Hydrochloride Monograph (AHFS DI)


• Verelan Prescribing Information (FDA)


• Verelan Sustained-Release Pellet-Filled Capsules MedFacts Consumer Leaflet (Wolters Kluwer)


• Verelan PM Prescribing Information (FDA)


• Verelan PM Sustained-Release Capsules Controlled Onset MedFacts Consumer Leaflet (Wolters Kluwer)

Compare Isoptin SR with other medications

• Angina
• Arrhythmia
• Bipolar Disorder
• Cluster Headaches
• High Blood Pressure
• Idiopathic Hypertrophic Subaortic Stenosis
• Migraine Prevention
• Nocturnal Leg Cramps
• Supraventricular Tachycardia

Where can I get more information?

• Your pharmacist can provide more information about verapamil.

See also: Isoptin SR side effects (in more detail)