Diltiazem
Also known as: Tildiem, Adizem, Dilzem
What it's for
Diltiazem is a calcium channel blocker. It lowers blood pressure and slows your heart rate. It treats high blood pressure, angina, and some heart rhythm problems.
Comes as: Tablets or capsules (often modified-release)
How to take it
- Adults: Dose varies. Usually 120mg to 360mg daily.
- Modified-release tablets are usually taken once or twice daily.
- Swallow whole - do not crush or chew.
- Take at the same time each day.
Doses here are typical. Always follow the instructions from your prescriber or on the packet — they come first.
Common side effects
- Swollen ankles
- Headaches
- Feeling dizzy or tired
- Flushing
- Constipation
The leaflet inside the packet lists all known side effects.
Important safety points
- Avoid grapefruit and grapefruit juice
- Do not stop suddenly without medical advice
- Tell your doctor if you have heart failure or liver problems
- May make you dizzy - take care when driving
Get medical help urgently if…
- Your heart beats very slowly or irregularly
- You have severe dizziness or fainting
- You have worsening chest pain
- You have severe swelling in your legs
Call NHS 111 for urgent advice, or 999 if someone is seriously unwell.
Before you act on anything here
This page is general information, written to help you understand — it is not personal medical advice and it cannot tell you what is right for you. Talk to your own GP, pharmacist or nurse about your own health.
- Need help now but it's not an emergency? Call NHS 111 or use 111.nhs.uk.
- Emergency? Call 999 or go to A&E.