Easy-to-read medicine information about diltiazem – what is it, how to take diltiazem safely and possible side effects.
|Type of medicine||Also called|
What is diltiazem?
Diltiazem is used to treat high blood pressure (hypertension) and to prevent chest pain (angina). It may help to increase your ability to 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 (such as atrial fibrillation). It works by relaxing blood vessels which helps to lower blood pressure. Diltiazem belongs to a group of medicines called calcium channel blockers. In New Zealand diltiazem is available in different strengths of tablets and capsules.
- tablets: 30 mg and 60 mg
- capsules: 120 mg, 180 mg, 240 mg and 360 mg.
- The dose of diltiazem will be different for different people. Your doctor will tell you which dose is right for you.
- Diltiazem is available in 2 forms: as immediate release tablets and slow release capsules.
- Tablets are usually taken 3 or 4 times a day.
- Capsules 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.
How to take diltiazem
Diltiazem tablets and capsules are available in different strengths. If your tablets or capsules look different to your last supply speak with your doctor or pharmacist for advice.
|Formulation||How to take it|
(30mg and 60mg)
(120 mg, 180 mg, 240 mg, 360 mg)
- Limit or avoid drinking alcohol while you are taking diltiazem. Alcohol may increase your chance of side-effects, such as feeling dizzy or light-headed.
- If you forget your dose, take it as soon as you remember. But, if it is nearly time for your next dose, just take the next dose at the right time. Do not take double the dose.
- Do not stop taking diltiazem suddenly; speak to your doctor or nurse before stopping.
Precautions – before taking diltiazem
- Do you have problems with your kidneys, lungs or liver?
- Do you have heart problems such as heart failure, a slow heart rate, low blood pressure or have you had a heart attack recently?
- Do you have diabetes?
- Are you pregnant, trying for a baby or breastfeeding?
- Are you taking any other medicines? This includes any medicines you buy without a prescription, such as herbal and complementary medicines.
If so, it’s important that you tell your doctor or pharmacist before you start diltiazem. Sometimes a medicine isn’t suitable for a person with certain conditions, or it can only be used with extra care.
Possible side effects
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?|
Diltiazem may interact with a few medications and herbal supplements, so check with your doctor or pharmacist before starting diltiazem or before starting any new medicines, including those you may buy over the counter.
The following links have more information on diltiazem.
New Zealand Formulary Patient Information: Diltiazem
- Diltiazem hydrochloride New Zealand Formulary
- Medical management of stable angina pectoris BPAC, 2011
- An update on managing patients with atrial fibrillation BPAC, 2017