Calan SR

Generic Name: Verapamil

  • What is this medication and its most common uses?

    Calan SR is a medicine known as a calcium channel blocker used to treat high blood pressure.

  • What should I know when beginning and continuing on this medication?

    How does this medication work?

    Calan SR is a sustained-release medicine, which releases medicine into your body throughout the day. Calan SR lowers your blood pressure by relaxing your blood vessels, which allows your blood to flow through with less resistance.

    What are the beneficial effects of this medication and when should I begin to have results?

    What: By lowering your blood pressure, Calan SR may lower your risk of a stroke or a heart attack.

    When: Calan SR may lower your blood pressure within 1 week. Though you may not feel an improvement or change in the way you feel, it is very important to keep taking your medicine as prescribed to keep your condition under control.

    How do I know it is working?

    Check your blood pressure regularly. Your healthcare provider may also check your blood pressure at every visit. Following an appropriate diet and exercise plan will also affect your blood pressure results.

  • What are the possible side effects of this medication?

    The following is not a full list of side effects. Side effects cannot be anticipated. If any develop or change in intensity, tell your healthcare provider as soon as possible. Only your healthcare provider can determine if it is safe for you to continue taking this medication.

    More common side effects may include: constipation, dizziness.

    Less common side effects may include:

    Risk of having a very slow heart rate, congestive heart failure (a condition in which your heart cannot pump enough blood throughout your body), low blood pressure, or liver injury.

  • Who should not take this medication?

    Do not take Calan SR if you are allergic to it or any of its ingredients.

    Do not take Calan SR if you have severe left ventricular dysfunction (impairment of a section of your heart that is responsible for pumping blood to the rest of your body).

    Do not take Calan SR if you have low blood pressure.

    Do not take Calan SR if you have sick sinus syndrome (abnormal heart rhythm) or a heart block, unless you have a pacemaker.

    Do not take Calan SR if you have atrial fibrillation or flutter (an irregular, fast heartbeat) and certain heart conduction problems (such as Wolff-Parkinson-White or Lown-Ganong-Levine syndrome).

  • What should I tell my healthcare provider before I take the first dose of this medication?

    Tell your healthcare provider about all prescription, over-the-counter, and herbal medications you are taking before beginning treatment with Calan SR. Also, talk to your healthcare provider about your complete medical history, especially if you have heart problems (such as heart failure or abnormal heart rhythms); kidney or liver disease; low blood pressure; certain conditions that cause muscle weakness (such as Duchenne's muscular dystrophy); or if you are pregnant, plan to become pregnant, or are breastfeeding.

    Also, talk to your healthcare provider about any planned surgeries or procedures.

  • What is the usual dosage?

    The information below is based on the dosage guidelines your healthcare provider uses. Depending on your condition and medical history, your healthcare provider may prescribe a different regimen. Do not change the dosage or stop taking your medication without your healthcare provider's approval.

    Adults: The recommended starting dose is 180 milligrams once a day. Your healthcare provider may increase your dose as needed, until the desired effect is achieved.

    If you are elderly, or have small stature or liver impairment, your healthcare provider may adjust your dose appropriately.

  • How should I take this medication?

    Take Calan SR exactly as prescribed by your healthcare provider.

    Take Calan SR in the morning with food.

  • What should I avoid while taking this medication?

    Do not change your dose or stop taking Calan SR without first talking to your healthcare provider.

  • What are the possible food and drug interactions associated with this medication?

    If Calan SR is taken with certain other drugs, the effects of either could be increased, decreased, or altered. It is especially important to check with your healthcare provider before combining Calan SR with the following: alcohol, blood pressure/heart medications (such as furosemide, prazosin, metoprolol, propranolol, or atenolol), carbamazepine, cholesterol-lowering medications known as statins (such as lovastatin or simvastatin), cimetidine, clonidine, cyclosporine, digoxin, disopyramide, flecainide, lithium, phenobarbital, quinidine, rifampin, telithromycin, or theophylline.

  • May I receive this medication if I am pregnant or breastfeeding?

    The effects of Calan SR during pregnancy are unknown. Calan SR can be found in your breast milk if you take it while breastfeeding. Do not take Calan SR while you are breastfeeding. Tell your healthcare provider immediately if you are pregnant, plan to become pregnant, or are breastfeeding.

  • What should I do if I miss a dose of this medication?

    If you miss a dose of Calan SR, take it as soon as you remember. However, if it is almost time for your next dose, skip the one you missed and return to your regular dosing schedule. Do not take two doses at once.

  • How should I store this medication?

    Store at room temperature. Protect from light and moisture.