Diltiazem

Calcium channel blocker
PRESCRIPTION ONLY IN INDIA

Diltiazem is a calcium channel blocker found in 1 medicine sold in India, such as Dilzem 30. Below: what it is for, how it works, how to take it, side effects, interactions and pregnancy advice.

What it is used for

Treats angina, high blood pressure and some fast heart rhythms.

How it works

A calcium channel blocker that slows the heart and relaxes arteries; for angina, high blood pressure and some fast heart rhythms. As a cream it treats anal fissures.

How to take it

Usually slow-release tablets once or twice a day, swallowed whole.

Common side effects

  • Ankle swelling
  • Headache
  • Dizziness
  • Constipation

Get medical help straight away if

Very slow heartbeat, fainting or breathlessness

Be careful

Can slow the heart; caution with other heart medicines.

Other medicines and interactions

Strong interactions: raises simvastatin, atorvastatin, ciclosporin and some other levels. Risky with beta blockers and digoxin (slow heart).

Pregnancy and breastfeeding

Not recommended in pregnancy; ask your doctor about breastfeeding.

Brands of Diltiazem (1)

Dilzem 30

Common questions

What is Diltiazem used for?

Treats angina, high blood pressure and some fast heart rhythms.

How does Diltiazem work?

A calcium channel blocker that slows the heart and relaxes arteries; for angina, high blood pressure and some fast heart rhythms. As a cream it treats anal fissures.

How should I take Diltiazem?

Usually slow-release tablets once or twice a day, swallowed whole.

What are the side effects of Diltiazem?

Common: Ankle swelling, headache, dizziness, constipation. Get help straight away for: Very slow heartbeat, fainting or breathlessness.

Does Diltiazem interact with other medicines?

Strong interactions: raises simvastatin, atorvastatin, ciclosporin and some other levels. Risky with beta blockers and digoxin (slow heart).

Is Diltiazem safe in pregnancy and breastfeeding?

Not recommended in pregnancy; ask your doctor about breastfeeding.

Does Diltiazem need a prescription in India?

Yes. In India it is a prescription (Schedule H) medicine, so a pharmacist should sell it only with a doctor's prescription.

Which brands contain Diltiazem?

Dilzem 30.

Sources and further reading

NHS (UK National Health Service) and MedlinePlus (US National Library of Medicine) are free, reviewed medicine guides. Brand names and doses there may differ from India.

Last reviewed 31 October 2026. Written by Satya Babu from standard prescribing information.

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For information only, not medical advice. This page is a plain-language summary written from standard prescribing information and the public guides linked below. Brands sometimes change their formula, so always check the composition printed on the pack. Doses here are typical adult doses; yours may differ. Do not start, stop or change a medicine without your doctor or pharmacist, and keep all medicines away from children. In an emergency, call 112 (India) or your local emergency number.