Used for Hypertension

View CALAN SR savings options available to you including Manufacturer Coupons, Rx Advantage Savings Card, Canadian Prescription Savings or CALAN SR Patient Assistance Program.

Programs are suitable for individuals who want to buy CALAN SR without insurance, with insurance or for those who are underinsured. You can pay as little as $0 per fill.*

Manufactured by Pfizer

*Applicable to Drug Coupons & Patient Assistance Programs

This content is intended for US audiences only

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    Save up to 90%

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Jamie Winn NowPatientGreen tick
Updated on 26 Apr 2024

Learn more about CALAN SR

What is CALAN SR?

What is CALAN SR?

CALAN SR is the brand name for verapamil and is available as an extended-release oral tablet.

What dosages is CALAN SR available in?

What dosages is CALAN SR available in?

CALAN SR is available as a 120 mg, 180 mg, 240 mg, and 360 mg extended-release oral tablet.

What is CALAN SR used for?

What is CALAN SR used for?

CALAN SR is a calcium channel blocker (CCB) used for high blood pressure

How does CALAN SR work?

How does CALAN SR work?

CALAN SR is a calcium channel blocker (CCB). It works by blocking calcium from entering your heart muscle. This helps lower how much your heart works to squeeze (contract) and relax. It also relaxes and opens up your blood vessels, including those of your heart. By relaxing your heart muscle and blood vessels, CALAN SR helps lower your blood pressure.

How do I take CALAN SR?

How do I take CALAN SR?

CALAN SR is typically taken by mouth once daily in the morning. Your dose might differ if you’re of older age, have low body weight, or have liver or kidney problems.

Is it safe for me to take CALAN SR?

Is it safe for me to take CALAN SR?

CALAN SR is a safe and effective treatment when used for FDA licensed indications. However, like all medications, they may give you unwanted side effects. You should always discuss potential side effects with your physician to ensure the medication is suitable and right for you. You should not take this medication if you have severe left ventricular dysfunction, hypotension (systolic pressure less than 90 mm Hg) or cardiogenic shock, sick sinus syndrome (except in patients with a functioning artificial ventricular pacemaker), second- or third-degree AV block (except in patients with a functioning artificial ventricular pacemaker), or atrial flutter or atrial fibrillation and an accessory bypass tract (eg, Wolff-Parkinson-White, Lown-Ganong-Levine syndromes).

CALAN SR Common Side Effects

CALAN SR Common Side Effects

Common side effects of CALAN SR include:

  • Constipation
  • Dizziness
  • Nausea
  • Low blood pressure
  • Headache
  • Sleepiness
  • Stomach discomfort (e.g., nausea, diarrhea)
CALAN SR Serious Side Effects

CALAN SR Serious Side Effects

Serious side effects are rare with CALAN SR. Contact your healthcare provider immediately if you experience any of the following.

  • Heart rhythm problems: chest pain, dizziness, shortness of breath, fainting, feeling like your heart skipped a beat, severe tiredness
  • Heart failure: shortness of breath, cough, tiredness, swelling of arms or legs, quick weight gain, dizziness
  • Liver problems: yellowing of the skin or eyes (jaundice), stomach pain or swelling, loss of appetite, dark urine, nausea, vomiting, confusion
  • Low blood pressure: dizziness, lightheadedness, weakness or tiredness, blurred vision, feeling thirsty, sweating, cold or pale skin, confusion, fast breathing
Effects of other drugs, drug classes and over-the-counter products on CALAN SR

Effects of other drugs, drug classes and over-the-counter products on CALAN SR

The following medications may interact with CALAN SR:

  • Cytochrome inducers/inhibitors – Clinically significant interactions have been reported with inhibitors of CYP3A4 (e.g., erythromycin, ritonavir) causing elevation of plasma levels of CALAN SR while inducers of CYP3A4 (e.g., rifampin) have caused a lowering of plasma levels of CALAN SR
  • HMG-CoA reductase inhibitors – The use of HMG-CoA reductase inhibitors that are CYP3A4 substrates in combination with CALAN SR has been associated with reports of myopathy/rhabdomyolysis.
  • Ivabradine – Concurrent use of CALAN SR increases exposure to ivabradine and may exacerbate bradycardia and conduction disturbances. Avoid co-administration of CALAN SR and ivabradine.
  • Aspirin – In a few reported cases, co-administration of CALAN SR with aspirin has led to increased bleeding times greater than observed with aspirin alone
  • Grapefruit juice – Grapefruit juice may increase plasma levels of CALAN SR
  • Alcohol – CALAN SR may increase blood alcohol concentrations and prolong its effects
  • Lithium – Increased sensitivity to the effects of lithium (neurotoxicity) has been reported during concomitant CALAN SR-lithium therapy; lithium levels have been observed sometimes to increase, sometimes to decrease, and sometimes to be unchanged. Patients receiving both drugs must be monitored carefully
Who makes CALAN SR?

Who makes CALAN SR?


Is CALAN SR safe in pregnancy?

Is CALAN SR safe in pregnancy?

It is not known if CALAN SR will harm your unborn baby. If you become pregnant while receiving CALAN SR, talk to your healthcare provider.


What to do if you missed your CALAN SR dose

The FDA's medical product safety reporting program for health professionals, patients and consumers.

Learn more about reporting side effects
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Medical Disclaimer

NowPatient has taken all reasonable steps to ensure that all material is factually accurate, complete, and current. However, the knowledge and experience of a qualified healthcare professional should always be sought after instead of using the information on this page. Before taking any drug, you should always speak to your doctor or another qualified healthcare provider.

The information provided here about medications is subject to change and is not meant to include all uses, precautions, warnings, directions, drug interactions, allergic reactions, or negative effects. The absence of warnings or other information for a particular medication does not imply that the medication or medication combination is appropriate for all patients or for all possible purposes.

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