Calan SR is a prescription medication used to treat hypertension (high blood pressure) and to control heart rate in certain heart conditions such as atrial fibrillation. It contains verapamil as an active ingredient. Verapamil belongs to a class of drugs known as calcium channel blockers. Calan SR works by relaxing the muscles of the heart and blood vessels, which helps to reduce blood pressure and regulate heart rate.
Verapamil comes as an extended-release formulation, which means that it releases the medication slowly over time to maintain therapeutic levels in the body. Verapamil is a medication that belongs to a class of drugs known as calcium channel blockers, which helps to lower blood pressure. By lowering high blood pressure, it can help to prevent strokes, heart attacks, and kidney problems.
Uses and Dosage
Verapamil is available as a 24-hour extended-release capsule that should be taken orally with food, as directed by your healthcare provider. Swallow the capsule whole or split without crushing or chewing, as doing so can lead to an increased risk of side effects. Take the medication regularly at the same time(s) each day to get the most benefit from it.
Do not stop taking the medication without consulting your doctor, and your dose may need to be gradually decreased. It may take up to a week before you see the full benefits of the medication for high blood pressure. If your condition does not improve or worsens, notify your healthcare provider as soon as possible.
The recommended initial dosage for Verapamil extended-release capsules is 180 milligrams (mg) taken orally once daily at bedtime. However, your healthcare provider may adjust your dose if needed based on your medical condition and response to treatment.
Common Side Effects of Calan SR (Verapamil ER):
- Tiredness or sluggishness
Serious Side Effects of Calan SR (Verapamil ER):
- Blurred vision
- Changes in heart rate
- Chest pain
- Dry mouth
- Enlarged breasts
- Flushed skin
- Frequent urination
- Heart failure and fluid buildup in lungs
- Muscle pain or cramps
- Numbness, burning, or tingling in arms or legs
- Overgrowth of gums (gingival hyperplasia)
- Ringing in ears
- Sleep disturbances or trouble sleeping (insomnia)
- Stomach discomfort (e.g., nausea, diarrhea)
Form and Strength
Calan SR (Verapamil ER) is available in the following forms and strength:
Verapamil ER: 24hour ER Capsule
- 120 mg
- 180 mg
- 240 mg
- Calan SR may cause low blood pressure, especially in people who are dehydrated or have certain heart conditions. Monitor blood pressure regularly while taking this medication.
- Calan SR may interact with other medications, such as beta blockers and digoxin. Tell your doctor about all the drugs you are taking.
- Calan should not be used in people with certain heart conditions, such as sick sinus syndrome or second- or third-degree atrioventricular block.
- Verapamil ER may cause dizziness or fainting, especially when starting or changing the dose. Avoid activities that require alertness until you know how Calan affects you.
- Verapamil ER should be used with caution in people with liver or kidney disease, as the drug is metabolized by the liver and excreted by the kidneys.
- Calan can cause serious heart rhythm disturbances in some people. This risk may be increased in people with certain heart conditions, such as atrial fibrillation.
- Verapamil may interact with grapefruit juice, which can increase the amount of the drug in the body and lead to side effects.
- Calan should not be used during pregnancy unless the benefits outweigh the risks. It may pass into breast milk and could harm a nursing infant.
- Calan SR should be used with caution in people with a history of liver or kidney disease, as the drug is metabolized by the liver and excreted by the kidneys.
- Verapamil ER may cause constipation in some people and may worsen symptoms of gastroesophageal reflux disease (GERD) or ulcers.
Frequently Asked Questions (FAQ)
Can Calan SR be taken with other medications?
Calan SR may interact with other drugs, tell your doctor about all the drugs you are taking. Certain medications such as beta blockers and digoxin may interact with Calan SR.
Can Calan SR be taken during pregnancy or breastfeeding?
Calan SR should only be used during pregnancy or breastfeeding if the potential benefits justify the potential risks to the fetus or infant. Women who are pregnant or breastfeeding should talk to their healthcare provider before using Calan SR.
How long does it take verapamil ER (Verelan) to start working to lower blood pressure?
Verapamil ER (Verelan) starts working within 1 week. When you first start the medication, your healthcare provider might make changes to your dose on a weekly basis depending on how well you’re tolerating the medication and how well it’s working to lower your blood pressure.