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verapamil

Pronunciation

Generic Name: verapamil (oral) (ver AP a mil)
Brand Name: Calan, Calan SR, Isoptin SR, Verelan, Verelan PM, Isoptin, Isoptin I.V., Covera-HS

What is verapamil?

Verapamil is a calcium channel blocker. 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 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 have a serious heart condition such as "sick sinus syndrome" or "AV block" (unless you have a pacemaker), severe heart failure, slow heartbeats that have caused you to faint, or certain heart rhythm disorders of the atrium (the upper chambers of the heart that allow blood to flow into the heart).

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 a serious heart condition such as:

  • "sick sinus syndrome" or "AV block" (unless you have a pacemaker);

  • severe heart failure;

  • slow heartbeats that have caused you to faint; or

  • certain heart rhythm disorders of the atrium (the upper chambers of the heart that allow blood to flow into the heart).

To make sure verapamil is safe for you, tell your doctor if you have:

  • congestive heart failure;

  • low blood pressure;

  • kidney disease;

  • liver disease; or

  • 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?

Follow all directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results. Do not take this medicine in larger or smaller amounts or for longer than recommended.

Do not crush, chew, or break an extended-release tablet or capsule. Swallow it whole.

If you have trouble swallowing an extended-release 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.

Your blood pressure will need to be checked often. Your kidney or liver function may also need to be checked.

If you need surgery, tell the surgeon ahead of time that you are using verapamil.

You should not stop using verapamil suddenly. Stopping suddenly may make your condition worse.

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.

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

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.

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:

  • fast, slow, or irregular heartbeats;

  • shortness of breath (even with mild exertion), swelling, rapid weight gain;

  • a light-headed feeling, like you might pass out;

  • anxiety, sweating, pale skin, wheezing, gasping for breath, cough with foamy mucus, chest pain;

  • flu symptoms (fever, chills, body aches, vomiting, diarrhea); or

  • feeling like you might pass out.

Common side effects may include:

  • constipation;

  • headache;

  • dizziness; or

  • stuffy nose, sinus pain, sore throat.

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.

See also: Side effects (in more detail)

Verapamil dosing information

Usual Adult Dose for Hypertension:

Oral:
Extended release capsules (Verelan PM (R)):
-Initial dose: 200 mg orally once a day at bedtime (usual dose in clinical trials); in rare cases, initial doses of 100 mg orally once a day at bedtime may be warranted in patients who have an increased response to verapamil (e.g., low-weight patients)
-Maintenance dose: Upward titration should be based on therapeutic efficacy and safety evaluated about 24 hours after dosing. If adequate response is not obtained with the initial dose, it may be titrated upward.
-Maximum dose: 400 mg/day

Extended release tablets (Covera HS (R)):
-Initial dose: 180 mg orally once a day at bedtime
-Maintenance dose: If adequate response is not obtained with the initial dose, it may be titrated upward.
-Maximum dose: 480 mg/day

Immediate release tablets (Calan (R)):
-Initial dose: 80 mg orally 3 times a day; alternatively, 40 mg orally 3 times a day may be considered in patients who might respond to lower doses (e.g., small stature, elderly)
-Maintenance dose: Upward titration should be based on therapeutic efficacy, assessed at the end of the dosing interval.
-Maximum dose: 480 mg/day

Sustained release capsules (Verelan (R)):
-Initial dose: 240 mg orally once a day in the morning (usual dose in clinical trials); alternatively, 120 mg orally once a day in the morning may be warranted in patients who may have an increased response to verapamil (e.g., small stature)
-Maintenance dose: Upward titration should be based on therapeutic efficacy and safety evaluated about 24 hours after dosing. If adequate response is not obtained with the initial dose, it may be titrated upward.
-Maximum dose: 480 mg/day

Sustained release tablets (Calan SR (R), Isoptin SR (R)):
-Initial dose: 180 mg orally once a day in the morning with food: alternatively, 120 mg orally once a day in the morning with food may be warranted in patients who may have an increased response to verapamil (e.g., small stature)
-Maintenance dose: Upward titration should be based on therapeutic efficacy and safety evaluated weekly, about 24 hours after the previous dose. If adequate response is not obtained with the initial dose, it may be titrated upward.
-Maximum dose: 480 mg/day

Comment:
-Daily dosages of 360 and 480 mg have been used but there is no evidence that dosages beyond 360 mg provided added effect.

Use:
-Management and treatment of essential hypertension

Usual Adult Dose for Supraventricular Tachycardia:

Parenteral:
-Initial dose: 5 to 10 mg (0.075 to 0.15 mg/kg) IV bolus over at least 2 minutes
-Repeat dose: 10 mg (0.15 mg/kg) IV (over 2 minutes) 30 minutes after the initial dose if the response is inadequate

Comment:
-Each dose should be administered over at least 2 minutes under continuous ECG and blood pressure monitoring.

Use: Treatment of supraventricular tachyarrhythmia, including:
-Rapid conversion to sinus rhythm of paroxysmal supraventricular tachycardia, including those associated with accessory bypass tracts
-Temporary control of rapid ventricular rate in atrial flutter/fibrillation EXCEPT when atrial flutter/fibrillation are associated with accessory bypass tracts

Usual Adult Dose for Angina Pectoris:

Oral:
Extended release tablets (Covera HS (R)):
-Initial dose: 180 mg orally once a day at bedtime; if adequate response is not obtained with 180 mg, the dose may be titrated upward.
-Maximum dose: 480 mg/day

Immediate release tablets:
-Initial dose: 80 to 120 mg orally 3 times a day; alternatively, 40 mg orally 3 times a day may be warranted in patients who may have an increased response to verapamil (e.g., renal/hepatic impairment, elderly)
-Maintenance dose: Upward titration should be based on therapeutic efficacy and safety evaluated about 8 hours after dosing. Dosage may be increased daily (e.g., patients with unstable angina) or weekly until optimum clinical response is obtained.
-Maximum dose: 480 mg/day

Uses:
-Management of angina
-Treatment of angina at rest, including vasospastic (Prinzmetal's variant) and unstable (crescendo, pre-infarction) angina
-Treatment of chronic stable (classic effort-associated) angina

Usual Adult Dose for Arrhythmias:

Oral:
Immediate release tablets (Calan (R)):
-Chronic atrial fibrillation in digitalized patients: 240 to 320 mg/day orally in 3 or 4 divided doses
-Prophylaxis of paroxysmal supraventricular tachycardia (PSVT) in non-digitalized patients: 240 to 480 mg/day orally in 3 or 4 divided doses

Comment:
-In general, the maximum effect for any given dosage will be apparent during the first 48 hours of therapy.

Uses:
-In association with digitalis for the control of ventricular rate at rest and during stress in patients with chronic atrial flutter and /or atrial fibrillation
-Prophylaxis of repetitive PSVT

Usual Geriatric Dose for Hypertension:

Extended release capsules (Verelan PM (R)):
-Initial dose: 100 mg orally once a day at bedtime
-Maintenance dose: Upward titration should be based on therapeutic efficacy and safety evaluated about 24 hours after dosing. If adequate response is not obtained with the initial dose, it may be titrated upward.
-Maximum dose: 400 mg/day

Immediate release tablets (Calan (R)):
-Recommended initial dose: 40 mg orally 3 times a day
-Maintenance dose: Upward titration should be based on therapeutic efficacy (assessed at the end of the dosing interval)
-Maximum dose: 480 mg/day

Sustained release capsules (Verelan (R)):
-Initial dose: 120 mg orally once a day in the morning
-Maintenance dose: Upward titration should be based on therapeutic efficacy and safety evaluated about 24 hours after dosing. If adequate response is not obtained with the initial dose, it may be titrated upward.
-Maximum dose: 480 mg/day

Sustained release tablets (Calan SR (R), Isoptin SR (R)):
-Initial dose: 120 mg orally once a day in the morning with food
-Maintenance dose: Upward titration should be based on therapeutic efficacy and safety evaluated weekly, about 24 hours after the previous dose. If adequate response is not obtained with the initial dose, it may be titrated upward.
-Maximum dose: 480 mg/day

Comments:
-An initial reduced dosage may be considered in patients who might respond to lower doses (e.g., elderly patients).
-Immediate release formulation daily dosages of 360 and 480 mg have been used, but there is no evidence that dosages beyond 360 mg provided added effect.

Use:
-Management and treatment of essential hypertension

Usual Geriatric Dose for Angina Pectoris:

Oral:
Immediate release tablets:
-Initial dose: 40 mg orally 3 times a day
-Maintenance dose: Upward titration should be based on therapeutic efficacy and safety evaluated about 8 hours after dosing. Dosage may be increased daily (e.g., patients with unstable angina) or weekly until optimum clinical response is obtained.
-Maximum dose: 480 mg/day

Comment:
-An initial reduced dosage may be warranted in patients who may have an increased response to lower doses (e.g., elderly patients).

Uses:
-Management of angina
-Treatment of angina at rest, including vasospastic (Prinzmetal's variant) and unstable (crescendo, pre-infarction) angina
-Treatment of chronic stable (classic effort-associated) angina

Usual Pediatric Dose for Supraventricular Tachycardia:

Parenteral:
Less than 1 year:
-Initial dose: 0.1 to 0.2 mg/kg (usual single dose range 0.75 to 1 mg) IV bolus over at least 2 minutes
-Repeat dose: 0.1 to 0.2 mg/kg (usual single dose range 0.75 to 2 mg) IV 30 minutes after the initial dose if the response is inadequate

1 to 15 years:
-Initial dose: 0.1 to 0.3 mg/kg (usual single dose range: 2 to 5 mg) IV bolus over at least 2 minutes
-Maximum initial dose: 5 mg
-Repeat dose: 0.1 to 0.3 mg/kg (usual single dose range: 2 to 5 mg) IV 30 minutes after the initial dose if the response is inadequate
-Maximum repeat dose: 10 mg

Comment:
-Each dose should be administered over at least 2 minutes under continuous ECG and blood pressure monitoring.

Use: Treatment of supraventricular tachyarrhythmia, including:
-Rapid conversion to sinus rhythm of paroxysmal supraventricular tachycardia, including those associated with accessory bypass tracts
-Temporary control of rapid ventricular rate in atrial flutter/fibrillation EXCEPT when atrial flutter/fibrillation are associated with accessory bypass tracts

What other drugs will affect verapamil?

Many drugs can interact with verapamil. Not all possible interactions are listed here. Tell your doctor about all your medications and any you start or stop using during treatment with verapamil, especially:

  • other blood pressure medicines;

  • aspirin;

  • bosentan;

  • clonidine;

  • digoxin, digitalis;

  • imatinib;

  • nefazodone;

  • St. John's wort;

  • an antibiotic--clarithromycin, erythromycin, telithromycin;

  • antifungal medication--itraconazole, ketoconazole, posaconazole, voriconazole;

  • cholesterol lowering medicines called "statins"--atorvastatin, fluvastatin, lovastatin, pitavastatin, pravastatin, rosuvastatin, simvastatin;

  • heart medication--nicardipine, quinidine;

  • hepatitis C medications--boceprevir, telaprevir;

  • HIV/AIDS medication--atazanavir, delavirdine, efavirenz, fosamprenavir, indinavir, nelfinavir, nevirapine, ritonavir, saquinavir;

  • seizure medication--carbamazepine, fosphenytoin, oxcarbazepine, phenobarbital, phenytoin, primidone; or

  • tuberculosis medication--isoniazid, rifabutin, rifampin, rifapentine.

This list is not complete and many other drugs can interact with verapamil. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Give a list of all your medicines to any healthcare provider who treats you.

Where can I get more information?

  • Your pharmacist can provide more information about verapamil.
  • Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.
  • Disclaimer: Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2012 Cerner Multum, Inc. Version: 13.01.

Date modified: November 30, 2016
Last reviewed: June 13, 2013

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