Generic Name: verapamil (ver-AP-a-mil)
Brand Name: Calan
Verapamil immediate-release is used for:
Treating high blood pressure and chronic stable angina (chest pain). It may be used alone or with other medicines. It is also used for treating and preventing supraventricular tachycardia (a rhythm disturbance of the heart) and for controlling heart rate response to other rhythm disturbances, specifically atrial fibrillation and atrial flutter. It may also be used for other conditions as determined by your doctor.
Verapamil immediate-release is a calcium channel blocker. It works by relaxing (dilating) your blood vessels, lowering blood pressure, and decreasing heart rate, which lowers the workload on the heart. It also dilates coronary arteries, increasing blood flow to the heart. It also works by slowing the electrical conduction in the heart, slowing heart rate, and/or normalizing heart rhythm.
Do NOT use verapamil immediate-release if:
- you are allergic to any ingredient in verapamil immediate-release
- you have certain heart problems (eg, left ventricular dysfunction, sick sinus syndrome, second- or third-degree heart block and do not have a pacemaker), very low blood pressure, or moderate to severe congestive heart failure (CHF)
- you have atrial fibrillation or flutter and a pre-excitation syndrome (extra conduction pathway in the heart), such as Wolff-Parkinson-White (WPW) syndrome or Lown-Ganong-Levine (LGL) syndrome
- you have shock caused by serious heart problems
- you are taking dofetilide or you have taken disopyramide within the past 48 hours
Contact your doctor or health care provider right away if any of these apply to you.
Before using verapamil immediate-release:
Some medical conditions may interact with verapamil immediate-release. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:
- if you are pregnant, planning to become pregnant, or are breast-feeding
- if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
- if you have allergies to medicines, foods, or other substances
- if you have heart failure or a recent heart attack with lung congestion, low blood pressure, or heart problems (eg, a very slow heart rate, heart block, heart valve disease)
- if you have kidney or liver problems, muscular dystrophy, or a neuromuscular disease
- if you are taking another blood pressure medicine or you are being treated for cancer
Some MEDICINES MAY INTERACT with verapamil immediate-release. Tell your health care provider if you are taking any other medicines, especially any of the following:
- Beta-blockers (eg, propranolol), clonidine, disopyramide, ketolides (eg, telithromycin), macrolides (eg, erythromycin), or ritonavir because they may increase the risk of verapamil immediate-release's side effects
- Phenobarbital, rifampin, or St. John's wort because they may decrease verapamil immediate-release's effectiveness
- Aldosterone blockers (eg, eplerenone), aspirin, carbamazepine, colchicine, cyclosporine, digoxin, dofetilide, doxorubicin, dronedarone, eletriptan, erythromycin, everolimus, flecainide, HMG-CoA reductase inhibitors (eg, lovastatin, simvastatin), lithium, narcotic pain relievers (eg, fentanyl), paclitaxel, quinazolines (eg, terazosin), quinidine, ranolazine, theophyllines, or tolvaptan because the risk of their side effects may be increased by verapamil immediate-release
This may not be a complete list of all interactions that may occur. Ask your health care provider if verapamil immediate-release may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.
How to use verapamil immediate-release:
Use verapamil immediate-release as directed by your doctor. Check the label on the medicine for exact dosing instructions.
- Take verapamil immediate-release by mouth with or without food.
- Check with your doctor before you eat grapefruit or drink grapefruit juice while you use verapamil immediate-release.
- If you miss a dose of verapamil immediate-release, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.
Ask your health care provider any questions you may have about how to use verapamil immediate-release.
Important safety information:
- Verapamil immediate-release may cause dizziness or lightheadedness. These effects may be worse if you take it with alcohol or certain medicines. Use verapamil immediate-release with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.
- Do not drink alcohol or use medicines that may cause drowsiness (eg, sleep aids, muscle relaxers) while you are using verapamil immediate-release; it may add to their effects. Ask your pharmacist if you have questions about which medicines may cause drowsiness.
- Verapamil immediate-release may cause dizziness, lightheadedness, or fainting; alcohol, hot weather, exercise, or fever may increase these effects. To prevent them, sit up or stand slowly, especially in the morning. Sit or lie down at the first sign of any of these effects.
- Patients who take medicine for high blood pressure often feel tired or run down for a few weeks after starting treatment. Be sure to take your medicine even if you may not feel "normal." Tell your doctor if you develop any new symptoms.
- Tell your doctor or dentist that you take verapamil immediate-release before you receive any medical or dental care, emergency care, or surgery.
- Lab tests, including liver function, kidney function, complete blood cell counts, and blood pressure may be performed while you use verapamil immediate-release. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.
- Use verapamil immediate-release with caution in the ELDERLY; they may be more sensitive to its effects.
- Verapamil immediate-release should not be used in CHILDREN; safety and effectiveness in children have not been confirmed.
- PREGNANCY and BREAST-FEEDING: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using verapamil immediate-release while you are pregnant. Verapamil immediate-release is found in breast milk. If you are or will be breast-feeding while you use verapamil immediate-release, check with your doctor. Discuss any possible risks to your baby.
Possible side effects of verapamil immediate-release:
All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:
Seek medical attention right away if any of these SEVERE side effects occur:
Constipation; dizziness; fatigue; headache; lightheadedness; nausea.
Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); chest pain; fainting; lightheadedness, especially when standing; severe dizziness; shortness of breath; swelling of the feet or hands; symptoms of liver problems (eg, yellowing of the skin or eyes, dark urine, pale stools, severe or persistent stomach pain, fever, general feeling of being unwell); unusually fast, slow, or irregular heartbeat.
This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects. To report side effects to the appropriate agency, please read the Guide to Reporting Problems to FDA.
If OVERDOSE is suspected:
Contact 1-800-222-1222 (the American Association of Poison Control Centers), your local poison control center, or emergency room immediately. Symptoms may include decreased mental status; dizziness; loss of consciousness; shortness of breath; slow or irregular heartbeat.Proper storage of verapamil immediate-release:
Store verapamil immediate-release at room temperature, between 59 and 86 degrees F (15 and 30 degrees C). Store away from heat, moisture, and light. Do not store in the bathroom. Keep verapamil immediate-release out of the reach of children and away from pets.
- If you have any questions about verapamil immediate-release, please talk with your doctor, pharmacist, or other health care provider.
- Verapamil immediate-release is to be used only by the patient for whom it is prescribed. Do not share it with other people.
- If your symptoms do not improve or if they become worse, check with your doctor.
- Check with your pharmacist about how to dispose of unused medicine.
This information should not be used to decide whether or not to take verapamil immediate-release or any other medicine. Only your health care provider has the knowledge and training to decide which medicines are right for you. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about verapamil immediate-release. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to verapamil immediate-release. This information is not specific medical advice and does not replace information you receive from your health care provider. You must talk with your healthcare provider for complete information about the risks and benefits of using verapamil immediate-release.
Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only your health care provider has the knowledge and training to decide which medicines are right for you. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this medicine. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not specific medical advice and does not replace information you receive from your health care provider. You must talk with your healthcare provider for complete information about the risks and benefits of using this medicine.