What are calcium channel blockers?

Calcium channel blockers (CCB) are a group of medicines used to treat different medical conditions. These include:

• angina (chest pain)
• hypertension (high blood pressure)
• some arrhythmias (abnormal heart rhythm)

Calcium channel blockers come in a tablet.

How do calcium channel blockers work?

CCBs work by stopping calcium from entering the cells of your heart and arteries. They help the muscle walls of your blood vessels relax. This can lower your blood pressure.

Some CCBs can also slow down how fast and hard your heart beats.

What types of calcium channel blockers might I be prescribed?

There are 2 different types of CCBs:

1. dihydropyridines
2. non-dihydropyridines

Your doctor will choose your CCB medicine based on your specific situation. This includes the condition they are treating and any other health problems you may have.

They may start you on a small dose and then slowly increase it over time.

Dihydropyridines

The dihydropyridines include medicines that end with 'dipine', like:

• amlodipine
• felodipine
• lercanidipine
• nifedipine

Non-dihydropyridines

Non-dihydropyridines are medicines like verapamil and diltiazem.

Verapamil can help treat:

• angina
• hypertension
• heart rhythm problems — like supraventricular tachycardia and atrial fibrillation (AF)

Diltiazem is mainly used to treat angina.

What are the side effects or risks of using calcium channel blocker?

Like all medicines, calcium channel blockers can cause side effects.

Common side effects include:

• dizziness
• headaches
• nausea
• flushed skin
• ankle swelling
• constipation

Serious side effects include:

• angina (chest pain)
• palpitations (abnormal heart beats)
• symptoms of a heart attack
• heart failure

To stop feeling dizzy, get up slowly when sitting or lying down. If you feel dizzy, sit back down and wait until the feeling goes away. Then try to get up slowly and with help.

Tell your doctor if you continue to feel dizzy after taking the medicine for a few weeks.

It's important to take your CCB exactly as your doctor recommends. Most CCBs are taken once a day.

Ask your doctor or pharmacist if you should take it with food or on an empty stomach.

Don't eat grapefruit or drink grapefruit juice while taking CCBs. Grapefruit can change how your body handles these medicines.

Speak to your pharmacist or doctor about any side effects that may be troubling you. Always check with your doctor before stopping any of your prescribed medicines.

When should I see my doctor?

If you have severe side effects including palpitations or shortness of breath, see a doctor immediately.

If you still feel dizzy after the first few weeks of treatment, see your doctor.

Tell your doctor about any other medicines you are taking before you start taking a calcium channel blockers. CCBs can interact with other medicines.

Are there any alternatives to this medicine?

Your doctor might prescribe other types of medicine to help with your health condition.

For example, ACE inhibitors and ARBs can be used to treat high blood pressure. Nitrates can be used to treat angina.

Talk to your doctor about the different medicines available to you.

Lifestyle changes can also help lower your blood pressure. These include:

• eating well
• doing enough physical activity
• keeping a healthy body weight
• reducing salt
• limiting alcohol
• quitting smoking or vaping

Resources and support

For more information about hypertension and how to manage it, see the Heart Foundation website.

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with 24 hours a day, 7 days a week.