Calan

Verapamil is a prescription medication used to treat chest pain, an irregular heartbeat, and high blood pressure. The extended- and sustained-release forms are used to treat high blood pressure. Verapamil belongs to a group of drugs called calcium channel blockers, which work by relaxing the blood vessels, making it easier for the heart to pump blood.

Verapamil comes in an immediate release tablet form and is taken 3 to 4 times a day, with or without food. The extended-release tablet and capsule forms are usually taken once day with or without food. The sustained-release tablet form is usually taken once or twice a day with food.

This medication is available in an injectable form to be given directly into a vein (IV) by a healthcare professional.

Common side effects of verapamil include constipation, nausea, low blood pressure, and headache. This medication can also cause dizziness. Do not drive or operate heavy machinery until you know how verapamil affects you.

Verapamil is a prescription medication used to treat chest pain, an irregular heartbeat, and high blood pressure. The extended- and sustained-release forms are used to treat high blood pressure.

These medications may be prescribed for other uses. Ask your doctor or pharmacist for more information.

Take verapamil exactly as prescribed by your doctor. Follow the directions on your prescription label carefully.

Oral:

• The recommended dose range for immediate-release tablets is 40 to 480 mg, divided into smaller doses and taken three or four times a day.
• The recommended dose range for verapamil extended- and sustained-release forms is 120 to 480 mg, divided into smaller doses and taken once or twice a day. Dose adjustments may be done based on your condition, severity of your condition, response to the medication, age, liver function, kidney function, and other medications you are taking.

Injectable:

• This medication is available in an injectable form to be dosed by a healthcare professional.

Oral/Injectable:

Serious side effects have been reported with verapamil including:

• heart failure. Tell your healthcare provider right away if you experience any of the following symptoms of heart failure:
  • worsening shortness of breath
  • new or increasing irregularities in your heart rate
• hypotension. Hypotension, or low blood pressure, may cause you to feel faint or dizzy. Inadequate fluid intake, excessive sweating, diarrhea, or vomiting can lead to an excessive fall in blood pressure too. Lie down if you feel faint or dizzy. Call your doctor right away.
• liver problems. Your doctor may want to closely monitor liver function lab tests. Tell your healthcare provider right away if you experience any of the following symptoms of liver problems:
  • a general feeling of discomfort, illness, or lack of well-being (malaise)
  • fever
  • right upper abdominal (stomach area) pain
• new irregular heartbeats. Tell your healthcare provider right away if you experience any of the following symptoms of an irregular heartbeat, medically known as an arrhythmia:
  • fast or slow heart beat
  • skipping beats
  • lightheadedness or dizziness
  • chest pain
  • shortness of breath
  • sweating

Verapamil can cause dizziness. Do not drive or operate heavy machinery until you know how verapamil affects you.

Do not take verapamil if you:

• have severe left ventricular dysfunction
• have low blood pressure (systolic pressure less than 90 mmHg) or cardiogenic shock
• have sick sinus syndrome (except in patients with a functioning artificial pacemaker)
• have second- or third-degree AV block (except in patients with a functioning artificial pacemaker)
• have atrial flutter or atrial fibrillation and an accessory bypass tract such as Wolff-Parkinson-White or Lown-Ganong-Levine syndromes
• have a known hypersensitivity to verapamil or the inactive ingredients

Oral/Injectable:

Serious side effects have been reported with verapamil. See the “Drug Precautions” section.

Common side effects of verapamil include:

• constipation
• dizziness
• nausea
• low blood pressure, medically known as hypotension
• swelling, medically known as edema
• fatigue
• difficulty breathing
• a slow heart rate, medically known as bradycardia
• rash
• flushing

This is not a complete list of verapamil side effects. Ask your doctor or pharmacist for more information.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements. Especially tell your doctor if you take:

• medications that block the enzyme CYP3A4 such as some macrolide antibiotics (clarithromycin, telithromycin), some HIV protease inhibitors (indinavir, nelfinavir, ritonavir, saquinavir), some HCV protease inhibitors (boceprevir, telaprevir), some azole antifungals (ketoconazole, itraconazole, posaconazole, voriconazole), conivaptan, delavirdine, and nefazodone
• medications that increase the activity of the enzyme CYP3A4 such as carbamazepine (Tegretol, Equetro, Carbatrol), phenobarbital, phenytoin (Dilantin), rifampin, St. John's wort, and nimodipine (Nimotop)
• medications to treat high blood pressure such as vasodilators, angiotensin-converting enzyme inhibitors (ACEIs), diuretics, beta blockers, and angiotensin receptor blockers (ARBs)
• anti-arrhythmic (irregular heartbeat) medications such as disopyramide (Norpace), flecainide (Tambocor), and quinidine
• simvastatin (Zocor)
• atorvastatin (Lipitor)
• digoxin (Lanoxin)
• alcohol
• cimetidine (Tagamet)
• lithium
• carbamazepine (Equetro, Tegretol, Carbatrol)
• rifampin 
• cyclosporine (Neoral, Sandimmune, Gengraf)
• theophylline
• telithromycin (Ketek)
• clonidine (Catapres)

This is not a complete list of verapamil drug interactions. Ask your doctor or pharmacist for more information.

Tell your doctor if you are pregnant or plan to become pregnant.

The FDA categorizes medications based on safety for use during pregnancy. Five categories - A, B, C, D, and X, are used to classify the possible risks to an unborn baby when a medication is taken during pregnancy.

Verapamil falls into category C. There are no well-controlled studies that have been done in pregnant women. Verapamil should be used during pregnancy only if the possible benefit outweighs the possible risk to the unborn baby.

Tell your doctor if you are breastfeeding or plan to breastfeed.

This medication is excreted in human milk. Because of the potential for adverse reactions in nursing infants from verapamil, nursing should be stopped while verapamil is being taken.

Verapamil can cause hypotension, or low blood pressure, which may cause you to feel faint or dizzy. Inadequate fluid intake, excessive sweating, diarrhea, or vomiting can lead to an excessive fall in blood pressure too.

• Lie down if you feel faint or dizzy. Call your doctor right away.

Verapamil can cause dizziness. Do not drive or operate heavy machinery until you know how verapamil affects you.

Verapamil capsules may also be taken by carefully opening the capsule and sprinkling the beads on a spoonful of applesauce.