Clarithromycin
Also known as: Klaricid
What it's for
Clarithromycin is an antibiotic for chest, skin, and ear infections. It is also used with other medicines to treat stomach ulcers caused by H. pylori bacteria.
Comes as: Tablets or liquid
How to take it
- Adults: Usually 250mg to 500mg twice a day.
- Take with or without food.
- Swallow tablets whole with water.
- Complete the full course of treatment.
Doses here are typical. Always follow the instructions from your prescriber or on the packet — they come first.
Common side effects
- Feeling sick, diarrhoea, or stomach pain
- Strange taste in your mouth
- Headache
- Difficulty sleeping
The leaflet inside the packet lists all known side effects.
Important safety points
- Can affect heart rhythm - tell your doctor if you have heart problems
- Interacts with many medicines including statins - check with your pharmacist
- Tell your doctor if you have liver or kidney problems
Get medical help urgently if…
- You have a fast, irregular heartbeat
- You have severe diarrhoea or blood in your stool
- You have yellowing of your skin or eyes
- You have severe muscle pain (if taking with a statin)
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.