• Basic Info
• Top Questions
• Clinical Info
• Interactions

What is verapamil?
Verapamil is in a class of drugs called calcium channel blockers. Verapamil relaxes (widens) blood vessels (veins and arteries), which makes it easier for the heart to pump and reduces its workload. Verapamil is used to treat hypertension (high blood pressure), to treat angina (chest pain), and to control some types of irregular heartbeats. Verapamil may also be used for purposes other than those listed in this medication guide.

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What is the price of this medication and similar alternatives?

This pricing information is subject to change at the sole discretion of DS Pharmacy. For the most current and up-to-date pricing information, please visit drugstore.com.

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What are the possible side effects of verapamil?

If you experience any of the following serious side effects, stop taking verapamil and contact your doctor immediately or seek emergency medical treatment:

• an allergic reaction (difficulty breathing; closing of the throat; swelling of the lips, tongue, or face; or hives);

• an unusually fast or slow heartbeat;

• shortness of breath (heart failure);

• fainting;

• abnormal behavior or psychosis;

• jaundice (yellowing of the skin or eyes); or

• swelling of the legs or ankles.

Other, less serious side effects may be more likely to occur. Continue to take verapamil and talk to your doctor if you experience

• unusual headache, fatigue, or tiredness;

• insomnia or trouble sleeping;

• vivid dreams;

• hair loss;

• nausea or diarrhea; or

• increased urination.

Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.

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How should I take verapamil?
Take verapamil exactly as directed by your doctor. If you do not understand these directions, ask your pharmacist, nurse, or doctor to explain them to you. Take each dose with a full glass of water. Verelan, Verelan PM, Calan, Isoptin, Covera-HS, and generic forms of regular-release verapamil can be taken with or without food. Taking the medication with food may reduce stomach upset if it occurs. Calan SR, Isoptin SR, and generic sustained-release verapamil (verapamil SR) may be more likely to cause stomach upset and should be taken with food to reduce this side effect.

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What is the most important information I should know about verapamil?
Do not stop taking this medication without first talking to your doctor. If you stop taking the medication, your condition could become worse. Do not crush, chew, or break extended-release forms of verapamil such as generic Covera-HS and Verelan PM. Swallow them whole. Generic verapamil SR, Isoptin SR, and Calan SR may be divided in half but should not be crushed or chewed.

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What happens if I miss a dose?
Take the missed dose as soon as you remember. However, if it is almost time for the next dose, skip the missed dose and take only the next regularly scheduled dose. Do not take a double dose of this medication.

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What other drugs will affect verapamil?
Before taking this medication, tell your doctor if you are taking any of the following drugs: cyclosporine (Sandimmune, Neoral); cimetidine (Tagamet, Tagamet HB); carbamazepine (Tegretol, Carbatrol); lithium (Lithobid, Eskalith, others); theophylline (Theo-Dur, Theochron, Theolair, Theobid, Elixophyllin, Slo-Phyllin, others); rifampin (Rifadin, Rimactane); phenobarbital (Luminal, Solfoton); an HMG CoA reductase inhibitor such as atorvastatin (Lipitor), lovastatin (Mevacor), simvastatin (Zocor), and others; or

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Can I take this if I am pregnant or trying to get pregnant or if I am breastfeeding?

Verapamil has been assigned to pregnancy category C by the FDA. Animal studies have failed to reveal evidence of teratogenicity; however, there was evidence of embryolethality and fetotoxicity at doses which produced maternal toxicity. There are no controlled data in human pregnancy. Verapamil should only be given during pregnancy when benefit outweighs risk.

Although verapamil is known to cross the human placenta, there are no reports linking verapamil with congenital defects in human pregnancy. Verapamil has been used safely to treat maternal hypertension and both maternal and fetal tachyarrhythmias. One case in which both digoxin and verapamil were successfully used to treat fetal supraventricular tachycardia at 32 weeks gestation is reported. Four weeks after the initiation of therapy, the fetus died, presumably due to complete heart block. Autopsy results are unavailable. Other than the association of fetal abnormality in this case, no adverse fetal or neonatal effects attributable to verapamil are reported. Because of the potential of reduced uterine blood flow associated with verapamil-induced hypotension, it is recommended that intravenous verapamil be used cautiously during pregnancy if it must be used. Data from the Michigan Medicaid Birth Defects Study failed to reveal an association between verapamil and congenital abnormalities (written communication, Franz Rosa, MD, Food and Drug Administration, 1994). This was a retrospective study of 229,101 completed pregnancies between 1985 and 1992, of which 76 were exposed to verapamil at some time during the first trimester and 172 were exposed to the drug at any time during pregnancy. Of these pregnancies, one cardiovascular defect was observed. This observation did not achieve statistical significance. These data do not support an association between verapamil and birth defects. A retrospective review of 78 women with first-trimester exposure to calcium channel blockers (CCBs) (41%, or 32 were taking verapamil) revealed no increase in major malformations compared with a control group matched for maternal age and smoking. This review suggests that CCBs do not represent a major teratogenic risk.

Verapamil is excreted into human milk. Side effects in the nursing infant are unlikely. However, the manufacturer recommends that due to the potential for serious adverse reactions in nursing infants, a decision should be made to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother.

Two case studies have shown that between 23% and 60% of the maternal serum verapamil concentration may be found in human milk at steady state. In one study, the authors calculated that the nursing infant would receive less than 0.01% of the mother's dose. This represents a miniscule amount of drug exposed to the nursing infant.

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Who should NOT use this medication?

• Severe left ventricular dysfunction (unless CHF is secondary to a supraventricular tachycardia amenable to verapamil therapy).
• Severe hypotension (SBP <90 mm Hg) or cardiogenic shock.
• Sick sinus syndrome (unless a functioning artificial ventricular pacemaker is present).
• Second- or third-degree AV block (unless a functioning artificial ventricular pacemaker is present).
• Atrial flutter or fibrillation associated with an accessory bypass tract (e.g., Wolff-Parkinson-White or Lown-Ganong-Levine syndrome).
• Patients currently receiving, or having recently received (i.e., within a few hours of IV verapamil therapy), IV β-adrenergic blocker therapy.
• Use of IV verapamil in patients with wide-complex ventricular tachycardia (QRS ≥0.12 seconds). (See Wide-Complex Ventricular Tachycardia under Cautions.)
• Known hypersensitivity to verapamil or any ingredient in the formulation.

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What does my medication look like?
Verapamil is available with a prescription generically and under the brand names Calan, Calan SR, Isoptin, Isoptin SR, Verelan, Verelan PM, and Covera-HS. Other brand or generic formulations may also be available. Ask your pharmacist any questions you have about this medication, especially if it is new to you. Calan 40 mg--round, pink, film-coated tablets Calan 80 mg--oval, peach-colored, film-coated, scored tablets Calan 120 mg--oval, brown, film-coated, scored tablets Calan SR 120 mg--oval, light-violet, film-coated tablets

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What happens if I overdose?
Seek emergency medical attention. Symptoms of a verapamil overdose include dizziness, weakness, chest pain, shortness of breath, fainting, an unusually fast or slow heartbeat, coma, slurred speech, and confusion.

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What should I discuss with my healthcare provider before taking verapamil?
Before taking this medication, tell your doctor if you have kidney or liver disease; other diseases of the heart or blood vessels such as sick sinus syndrome, aortic stenosis, heart failure, heart block, Wolff-Parkinson-White syndrome, coronary artery disease, or low blood pressure; or muscular dystrophy. You may not be able to take verapamil, or you may require a dosage adjustment or special monitoring during treatment if you have any of the conditions listed above. Verapamil is in the FDA pregnancy category C. This means that it is not known whether verapamil will be harmful to an unborn baby. Do not take verapamil without first talking to your doctor if you are pregnant or could become pregnant during treatment.

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Can I stop taking the medication if I feel better?
Even though you may feel better you should not stop taking your high blood pressure medication without first checking with your healthcare provider.

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I am on so many medications; do I have to take them all?
This is called polypharmacy—many different medications being used at the same time by one person. Sometimes, being on multiple medications is acceptable and appropriate but at other times it may be problematic. If you are receiving your medications from multiple physicians you need to ensure that they all know what medications you are taking. The best way to do this is to make a list of all the medications you are currently using, including all nutritional supplements, homeopathic remedies, vitamins and over-the-counter drugs (if possible, also include all the diseases you have been diagnosed with). Give a copy to every doctor who takes care of you so they have it on file, this way they can avoid duplicating medications and perhaps even try to consolidate some. After every doctor's visit remember to update the list accordingly. Also, as much as you possibly can, try to use the same pharmacy to fill all your prescriptions, this way any potential drug interactions can be caught and averted.

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Where can I get more information?
More Information

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