Diltiazem
Diltiazem relaxes blood vessels and slows electrical conduction through the heart. It may be used for hypertension, angina or selected fast heart rhythms.
Key points
- Immediate- and modified-release diltiazem products are not automatically interchangeable.
- Slow pulse, conduction disease, heart failure and other rate-slowing medicines require review.
- Fainting, severe breathlessness, chest pain or a very slow heartbeat with weakness needs urgent care.
Listings are for comparison only. Suitability and supply depend on clinician and pharmacy checks, stock, destination rules and prescription requirements.
How it works
Diltiazem blocks L-type calcium channels in heart and vascular smooth muscle, reducing conduction through the AV node and relaxing arteries.
Important safety checks
Heart rhythm and conduction, heart failure, low blood pressure, liver or kidney disease and interacting medicines require review. Beta blockers and several other medicines can add to rate-slowing or blood-pressure effects. Follow the exact formulation instructions and do not stop treatment abruptly without advice.
When to seek urgent care
Seek urgent help for fainting, new or worsening chest pain, severe breathlessness, a very slow or irregular heartbeat with weakness, facial swelling or breathing difficulty.

