This NHS content is written for people in England. Medicine names, availability, prescribing and services may differ in other countries.
Who can take clarithromycin
Most adults and children can take clarithromycin.
Who may not be able to take clarithromycin
Clarithromycin is not suitable for some people.
To make sure it's safe for you, tell your doctor if you:
- have ever had an allergic reaction to clarithromycin or any other medicine
- have ever had diarrhoea when you have taken antibiotics
- have heart problems, including irregular heartbeats (arrhythmia)
- have abnormally low levels of potassium or magnesium in your blood
- have myasthenia gravis – clarithromycin can make your symptoms worse
- have phenylketonuria – some brands of liquid clarithromycin contain the sweetener aspartame, which you should avoid if you have this condition
- are pregnant, trying to get pregnant, or breastfeeding
- have liver or kidney problems
View the original NHS website page ↗. Refreshed 19 August 2026.
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