Calcium channel blocking agents are not usually the first drugs prescribed for the management of
. In cases of uncomplicated hypertension, physicians often prescribe a diuretic, beta-blocking agent, or acetylcholinesterase (ACE)-inhibitor first. If hypertension cannot be controlled with one of these drugs or you are unable to tolerate the medication, your physician may recommend a calcium channel blocking agent. Data from the 1990s suggested that short acting calcium blockers, such as nifedipine, may possibly increase the risk of heart attacks, but more recent studies clearly show that, properly selected, calcium channel blockers can effectively control hypertension and decrease associated mortality.
is not a disease itself but is the primary symptom of coronary artery disease. It is typically experienced as chest pain, which can be mild, moderate, or severe, but is often reported as a dull, heavy pressure that may resemble a crushing object on the chest. Pain often radiates to the neck, jaw, or left shoulder and arm. Calcium blockers may relieve symptoms associated with angina, but they probably do not improve long-term outcomes or prevent death.
How Calcium Channel Blocking Agents Work
These medications affect the movement of calcium into the cells of the heart and blood vessels. As a result, they relax blood vessels and increase the supply of blood and oxygen to the heart while reducing its workload.
Precautions While Using These Medicines
Check your other medications
If you are taking a calcium channel blocking agent to treat high blood pressure, tell your doctor about any other drugs or supplements, both prescription and over-the-counter (nonprescription), that you are taking or considering taking. Some drugs may contain ingredients that cause an increase in your blood pressure. These include: over-the-counter medicines for appetite control,
, or sinus problems.
Report grapefruit intake
Grapefruit juice or grapefruit, when taken with some calcium channel blocking agents, can increase the absorption of the drug and therefore its level in your blood. The largest effect is seen with the felodipine (Plendil) family of calcium channel blockers. If you regularly eat or drink grapefruit and are taking one of the following medications, or indeed any calcium channel blocker, tell your doctor so that he or she can factor that in to your dosage:
If you have been using this medication regularly, do not stop taking it suddenly, as this may lead to a return and/or worsening of your angina or high blood pressure. Instead, check with your doctor on how best to gradually wean yourself off of this drug.
Go easy on the exercise
Calcium channel blocking agents can reduce or prevent chest pain that occurs with exercise and physical exertion, making it easy to overdo it on exercise. Therefore, before beginning or changing your exercise program, discuss with your doctor an appropriate level of physical activity for you.
Mind your head
After taking a dose of this medicine, you may get a temporary headache. This is more common if you are taking felodipine, isradipine, or nifedipine. This headache should occur less often once you have taken the medication for awhile. However, if it continues or if the headaches are severe, alert your doctor.
Care for your teeth and gums
Upon starting treatment with a calcium channel blocking agent, some people notice tenderness, swelling, or bleeding of their gums. To help prevent this, brush and floss regularly and carefully, and massage your gums. Also, have your teeth professionally cleaned regularly and discuss such problems with your doctor or dentist.
Be cautious with certain medical conditions
The presence of other medical problems may affect the use of the calcium channel blocking agents. Make sure you tell your doctor if you have any other medical problems, especially:
Heart rhythm problems,
congestive heart failure
, or blood vessel disorders (or a history of) – Calcium channel blocking agents may make some heart conditions worse. Bepridil can cause serious heart rhythm problems.
Kidney disease or liver disease – The effects of the calcium channel blocking agent may be increased.
Tell your doctor about all the medications you take; some should not be taken with calcium channel blocking agents, while others may require a different dosage level.
If you miss a dose, take it as soon as possible. But if it is almost time for your next dose, skip the missed dose and stick to your regular dosing schedule. Never take a double dose.
Possible Side Effects
The side effects listed here have been reported for at least one of the calcium channel blocking agents, not necessarily all of them. However, since many of the effects of calcium channel blocking agents are similar, it is possible that these side affects may occur with any one of these medicines, although they may be more common with some than with others.
Check with your doctor if any of the following side effects occur.
These side effects are considered less common:
Breathing difficulty, coughing, or wheezing
Irregular or fast, pounding heartbeat
Slow heartbeat (less than 50 beats per minute) This is a concern with bepridil, diltiazem, and verapamil only.
Swelling of ankles, feet, or lower legs (This is more common with amlodipine, felodipine, and nifedipine.)
These side effects are considered rare:
Bleeding, tender, or swollen gums
Chest pain (may appear about 30 minutes after medicine is taken)
Painful, swollen joints (a concern with nifedipine only)
Trouble seeing (a concern with nifedipine only)
These side effects may occur, but usually do not require medical attention and may go away as your body adjusts to the medication. However, if these effects linger or are bothersome, check with your doctor:
Dizziness or lightheadedness (more common with bepridil and nifedipine)
Dry mouth (more common with amlodipine)
Flushing and feeling of warmth (more common with nicardipine and nifedipine)
Headache (more common with amlodipine, felodipine, isradipine, and nifedipine)
Nausea (more common with bepridil and nifedipine)
Unusual tiredness or weakness
Other Uses for Calcium Channel Blocking Agents
Once a medicine has been approved for marketing for a certain use, experience may show that it is also useful for other medical problems. Although these uses are not included in product labeling, calcium channel blocking agents are used in certain people with these conditions:
Hypertrophic cardiomyopathy (a heart condition) – verapamil
Eisenberg MJ, Brox A, Bestawros AN.
Calcium channel blockers: an update.
Am J Med.
Opie LH, Yusuf S, Kubler W. Current status of safety and efficacy of calcium channel blockers in cardiovascular diseases: a critical analysis based on 100 studies. Prog Cardiovasc Dis. 2000;43(2):171-196.
Please be aware that this information is provided to supplement the care
provided by your physician. It is neither intended nor implied to be a
substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER
IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the
advice of your physician or other qualified health provider prior to
starting any new treatment or with any questions you may have regarding a