Diltiazem

Sounds like 'dil-tye-ah-zem'

Key points about diltiazem

Diltiazem is used to treat high blood pressure and irregular heart beat, and to prevent chest pain (angina).
Diltiazem is also called Cardizem CD®.
Find out how to take it safely and possible side effects.

Diltiazem belongs to a group of medicines called calcium channel blockers or calcium antagonists. It doesn’t affect the amount of calcium in your blood or bones.

Diltiazem is used to treat high blood pressure (hypertension) and to prevent chest pain (angina). It may help you to do more exercise and decrease how often you get chest pain.

Diltiazem may also be used to control your heart rate if you have a fast or irregular heartbeat (eg, atrial fibrillation).

It works by relaxing and widening blood vessels which helps to lower blood pressure. It also reduces the force and rate of your heartbeat which helps with angina.

In Aotearoa New Zealand diltiazem is available in capsules of different strengths (120 mg, 180 mg and 240 mg).

The dose of diltiazem will be different for different people. Your doctor will tell you which dose is right for you.
Diltiazem capsules are slow release (they release the medicine gradually over time) and are usually taken once a day.
Always take your diltiazem exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much diltiazem to take, how often to take it, and any special instructions.

Timing: Diltiazem capsules are usually taken once a day. Take your dose at about the same time each day.
Food: You can take diltiazem capsules with or without food.
Swallow the capsules whole with a glass of water: Don't open or chew them. The slow-release capsules have been designed to release the right dose of medicine slowly. If you open or chew them, they won't work properly.
Missed dose: If you forget your dose, take it as soon as you remember. But if it's nearly time for your next dose, just take the next dose at the right time. Don't take double the dose.

Here are some things to know when you're taking diltiazem. Other things may be important as well, so ask your healthcare provider what you should know about.

Other medicines: Diltiazem interacts with some medicines, herbal supplements and rongoā Māori, so check with your doctor or pharmacist before starting diltiazem and before starting any new products.
Driving: Diltiazem can make you dizzy so be careful when you're driving or using tools until you know how this medicine affects you.
Alcohol: Limit drinking alcohol while you’re taking diltiazem. Alcohol may increase your chance of side-effects, such as feeling dizzy or light-headed.
Don’t stop taking diltiazem suddenly: Speak to your healthcare provider before stopping.
Pregnancy or breastfeeding: Tell your doctor if you’re pregnant, planning a pregnancy or want to breastfeed your pēpi.
Angina: If you’re taking diltiazem for angina and you continue to have angina tell your doctor.
Physical activity: When you start taking diltiazem don’t overdo physical activity. Improve your fitness slowly over time.
Grapefruit, grapefruit juice or sour/Seville oranges: These may react with diltiazem, talk to your pharmacist about this. See grapefruit and medicines(external link).
Appearance: There are different strengths of this capsule. If the colour or appearance of your medicine looks different than before, always check with your pharmacist.

Like all medicines, diltiazem can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine.

Side effects	What should I do?
Headache	This is quite common when you first start taking diltiazem and usually goes away with time. Tell your doctor if this bothers you or if it doesn't go away after a few days.
Dizziness Feeling light-headed Feeling faint when you stand up	This is common when you first start taking diltiazem and usually goes away with time. Be careful when getting up from either lying down or sitting to avoid falls. Avoid drinking alcohol.
Changes in your heartbeat (either too slow, too fast or irregular) Chest tightness Wheezing or trouble breathing Swelling of the ankles or feet	Tell your doctor immediately or ring Healthline 0800 611 116.