Overview

Calan belongs to a class of medicines called calcium channel blockers.

Because of their safety and effectiveness, these drugs have helped
revolutionize the treatment of high blood pressure.

Other uses of
calcium channel blockers include treatment of irregular heart rhythms and
angina.

There is even some preliminary research that suggests some of
these compounds may be able to prevent migraine headaches, ease nighttime leg
cramps, asthma and Raynaud’s disease, and perhaps reduce atherosclerosis.

Despite these future possibilities, Calan SR has been approved only for
the treatment of hypertension.

Side Effects and Interactions

One of the most common side effects of Calan is
constipation. Although bothersome, this can often be controlled with fluid and
fiber or a bulk-forming laxative such as psyllium.

Another reaction to
be alert for is low blood pressure, which may show up as lightheadedness and
dizziness.

Although uncommon, other adverse reactions include headache,
fluid retention leading to swelling of arm and legs, nausea, tiredness, rash and
slowed heart rate. Report any symptoms or suspected side effects to your
physician promptly.

Calan can interact with a number of other drugs,
including several that are used to treat high blood pressure or heart
conditions, the asthma medicine theophylline, the anticonvulsant Tegretol, the
transplant medication Sandimmune and the anti-tuberculosis agent rifampin.

The popular antidepressant Prozac may increase the likelihood of side
effects from Calan.

Over-the-counter calcium supplements can reduce the
effectiveness of Calan. Check with your doctor and pharmacist to make sure Calan
is safe in combination with any other drugs you take.

Special Precautions

Although Calan may be prescribed for a variety of cardiac indications, there are some serious heart conditions that may be worsened by this drug.

Your doctor should be fully informed about any heart problem, kidney disease, liver disease, low blood pressure and muscular dystrophy.

Careful monitoring is called for in any of these cases due to an increased risk of toxicity.

In addition, older people may be more sensitive to the blood-pressure-lowering effects of Calan SR.

Taking the Medicine

The manufacturer recommends that this sustained-release formulation should be taken with food,
preferably in the morning with breakfast.

If a second dose is needed it should be swallowed
approximately 12 hours later.

Do not stop taking Calan SR suddenly, as this could lead to
complications.

Your doctor will tell you how to taper off gradually if you no longer need this medication.

Join Over 52,000 Subscribers at The People's Pharmacy

Each week we send two free email newsletters with breaking health news, prescription drug information, home remedies and a preview of our award-winning radio show. Join our mailing list and get the information you need to make confident choices about your health.

  1. C. C.
    Reply

    I’m taking the generic Verapamil ER for blood pressure and angina. My Dentist tells me that it can increase cavities because it causes saliva to thicken. If that is so; Can it also thicken Phlegm? I have COPD and since I started the Med I’ve had a hard time clearing my throat. Also seem to be making more trips to the bathroom at night despite my GP’s insistence that it’s not a diuretic.

  2. MCK
    Reply

    Recently my Prescription Drug Insurance denied coverage for Calan SR – which I have been taking for a number of years – substituting the generic Verapamil ER. Subsequently I have experienced increased incidence of x-systoles.
    For the past 4 days I have been taking the Calan SR (purchased privately) with no noted side effects. Do you have any information as to differences between the the Brand and the Generic as mentioned above?
    I am under the active supervision of my physician and I take the medication as instructed.

  3. E L
    Reply

    Since taking verapamil, it has lowered BP, but occasionally feel short of breath and tired. Then it passes, not sure if it is the medication or been recently diagnosed with A. Fib

What Do You Think?

Share your thoughts with others, but be mindful of protecting your own and others' privacy. Not all comments will be posted. Advice from web visitors is not a substitute for medical attention. Do not stop any medicine without checking with the prescriber. In posting a comment, you agree to our commenting policy and website terms and conditions.