Pulmonary arterial hypertension (PAH) is high blood pressure in the arteries that carry blood from your heart to your lungs. Your doctor might prescribe high doses of a blood pressure medication known as a calcium channel blocker to help.
Most people think of calcium in terms of how it benefits your bones. Your heart needs it, too. The mineral helps your heart pump blood. But when you have hypertension, calcium can cause the muscle to squeeze too hard, which adds to the pressure. That’s why you might need medicine to lower the amount of calcium that goes to your heart.
How Do Calcium Channel Blockers Work?
Calcium gets into your cells through calcium channels. Those are cell pathways specifically designed to carry this mineral throughout the body. Calcium channel blockers only block some of the pathways. It’s like closing certain roads and leaving others open. As a result, less of it gets to the heart.
Once there’s less calcium in the cells of the muscle lining of blood vessels, your blood vessels begin to relax and open wider. Some of the medications in this drug class also slow the heart rate a bit. All of this adds up to lower blood pressure. It can lower pressure in the pulmonary arteries, too.
There are two kinds of calcium channel blockers:
- Dihydropyridines, which work only on blood vessels and cause them to relax
- Non-dihydropyridines, which work on both blood vessels and the heart muscle
Who Benefits From Calcium Channel Blockers for PAH?
Calcium channel blockers seem to help people with idiopathic PAH most. That’s PAH with no obvious cause. Your doctor may do a test called a vasodilator challenge to see how your heart would respond to this type of medication before prescribing it.
These medications wouldn’t be expected to help if you have PAH because of:
- A gene you inherited
- A heart defect you were born with (congenital)
- Using certain illicit drugs
- Another known cause
How Do You Take Calcium Channel Blockers for PAH?
You need to take a much higher dose for PAH than you would for the other health conditions these medications treat.
Doctors most often prescribe:
- Amlodipine
- Diltiazem
- Nifedipine
These come in the form of a pill or a liquid (in the case of amlodipine) that you swallow.
You may start at a lower dose and gradually move up to the full necessary dose. Doing it this way can help you tolerate the drug a little better and potentially avoid side effects.
What Are the Side Effects of Calcium Channel Blockers for PAH?
Like any medication, calcium channel blockers may trigger some unpleasant side effects. The most common are:
- Peripheral edema, swelling in your legs from fluid buildup
- System hypotension, abnormally low blood pressure
- Nausea
- Digestive problems, such as constipation and heartburn (GERD)
- Headaches
- Lightheadedness or dizziness
These side effects typically go away within a few days.
Go to the emergency room right away if you have any of the following symptoms after starting calcium channel blockers:
- Shortness of breath
- Chest pain
- Racing heart
- Fainting
Show Sources
Photo Credit: E+/Getty Images
SOURCES:
American Heart Association: “Pulmonary Hypertension – High Blood Pressure in the Heart-to-Lung System.”
Frontiers: “The Role of Calcium in the Human Heart: With Great Power Comes Great Responsibility.”
Mayo Clinic: “Calcium Channel Blockers,” “Raynaud’s Disease,” “Anal fissure.”
Cleveland Clinic: “Calcium Channel Blockers.”
Pulmonary Hypertension Association UK: “Calcium Channel Blockers.”
Current Cardiovascular Risk Reports: “Management of Pulmonary Arterial Hypertension.”
Drugs.com: “Diltiazem hydrochloride monograph.”
National Library of Medicine: “Nifedipine,” “Amlodipine.”
Patient.info: “Calcium channel blockers.”
