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About diltiazem - Brand names: Adizem, Angitil, Tildiem, Viazem, Zemtard

Diltiazem is a medicine used to treat high blood pressure.

If you have high blood pressure, taking diltiazem helps to prevent coronary heart disease, heart attacks and strokes.

It works by lowering your blood pressure and making it easier for your heart to pump blood around your body.

Diltiazem is also used to:

Diltiazem is available on prescription only. It comes as tablets or capsules to treat high blood pressure, angina or Raynaud's. It's also available as a cream or ointment to treat anal fissures.

Key facts

  • Diltiazem starts to work on the day you start taking it, but for high blood pressure and angina it may take a couple of weeks to work fully.
  • You can take diltiazem at any time of day. Try to make sure it's around the same time or times every day.
  • Common side effects include swollen hands, ankles or feet, a pounding heartbeat (palpitations) and constipation.
  • If diltiazem makes you feel dizzy or drowsy, do not drive a car, ride a bike, or use tools or machinery until you feel better.

Page last reviewed: 10 March 2023
Next review due: 10 March 2026