Verapamil belongs to the class of medications called calcium channel blockers. The sustained release (SR) form of this medication is used for the treatment of mild-to-moderate high blood pressure, when beta-blockers or diuretics (water pills) are not recommended or have caused unacceptable side effects. The immediate-release form of verapamil may be used to treat certain abnormal heart rhythms, angina (chest pain) and certain conditions where the heart muscle is enlarged, as well as blood pressure. It works to control blood pressure and reduce the number of angina attacks by relaxing blood vessels. It also helps to normalize heart rhythms.
This medication is available as a 2.5 mg/mL injection.
For most conditions, the dose of verapamil for adults is 80 mg to 120 mg taken 3 or 4 times daily with food. This dose may be increased to a maximum of 480 mg daily. When treating specific conditions where the heart muscle is enlarged and preventing the heart from working efficiently, the dose may be increased to 600 mg or 720 mg of verapamil divided throughout the day.
If you use the sustained-release (SR) tablets, the recommended dose of verapamil ranges from 180 mg to 480 mg daily with food. The SR tablets are to be taken once daily if the dose is 240 mg or less. Doses over 240 mg daily of the SR tablets should be taken in 2 divided doses (morning and evening) with food. Do not chew or crush the sustained-release tablets. Do not take more than 480 mg daily.
Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.
It is important to take this medication exactly as prescribed by the doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.
Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.
Do not use verapamil if you:
This medication should not be given to people who are in cardiogenic shock or those who are suffering from certain types of complicated heart attack.
Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.
Although most of the side effects listed below don’t happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.
Check with your doctor as soon as possible if any of the following side effects occur:
Stop taking the medication and seek immediate medical attention if any of the following occur:
Heart failure: Verapamil works partially by reducing the force of the heart’s contractions which can cause the symptoms of heart failure to become worse. If you have heart failure that is not well-corrected, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Kidney function: Kidney disease or reduced kidney function may cause this medication to build up in the body, causing side effects. If you have reduced kidney function or kidney disease, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Liver function: Liver disease or reduced liver function may cause this medication to build up in the body, causing side effects. If you have liver problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Your doctor may want to test your liver function regularly with blood tests while you are taking this medication.
Verapamil may also reduce liver function and can cause liver failure. If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.
Low blood pressure and heart rate: Low blood pressure symptoms of tiredness and weakness with faintness have been reported following single doses and even after some months of treatment with verapamil. Some people may require a reduced dose. Verapamil can cause very low heart rate for some people. Report an abnormally low heart rate (less than 50 beats per minute) or persistent fatigue to your doctor.
Neuromuscular disease: If you have a neuromuscular disease such as myasthenia gravis, Lambert-Eaton syndrome, or Duchenne’s muscular dystrophy, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Pregnancy: Verapamil reaches the developing baby if it is taken during pregnancy. This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.
Breast-feeding: This medication passes into breast milk. If you are a breast-feeding mother and are taking verapamil, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.
Children: The safety and effectiveness of using this medication have not been established for children.
Seniors: Seniors may have a higher risk of side effects with this medication. Your doctor may recommend lower doses to reduce this risk.
There may be an interaction between verapamil and any of the following:
All material copyright MediResource Inc. 1996 – 2020. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: www.medbroadcast.com/drug/getdrug/Verapamil-Hydrochloride-Injection-by-Sandoz-Canada-Incorporated