Tetracycline antibiotics
Tetracyclines are antibiotics that stop bacteria from growing by blocking how they make proteins. They are used to treat a range of bacterial infections, including some chest, urinary, skin and sexually transmitted infections, and some doctors also prescribe them for acne. Examples include doxycycline, tetracycline and minocycline. They can stain developing teeth, so they are usually avoided in pregnancy and in young children.
Pharmacist review in progress. This page is based on the sources listed below and is being checked by our registered pharmacist.
How do Tetracycline antibiotics work?
Tetracyclines attach to the small (30S) part of the bacterial ribosome, the machinery bacteria use to build proteins. Without new proteins the bacteria cannot grow or multiply, and the body's defences clear the infection. They have no effect on viruses.
Active ingredients of this type
These active ingredients belong to Tetracycline antibiotics. They are listed A to Z.
- Doxycycline: Doxycycline is a tetracycline antibiotic used to treat certain bacterial infections.
Common questions
Why are tetracyclines avoided in pregnancy and young children?
They can settle in developing teeth and bones, causing lasting tooth staining and affecting bone growth. Doctors usually avoid them in pregnancy, while breastfeeding and in young children unless the benefit clearly outweighs the risk. Tell your doctor if you are or may be pregnant.
Why is sunlight a concern with tetracyclines?
These medicines can make skin burn more easily in sunlight, causing a rash, itching or redness. Cover up, use sunscreen and avoid strong sun and sunbeds during the course, and tell your doctor if your skin reacts.
Sources
- Doxycycline hyclate tablets and capsules: prescribing information (label revised 4/2025). DailyMed, US National Library of Medicine
- Doxycycline. NHS (UK)
- ATC/DDD Index: J01AA Tetracyclines. WHO Collaborating Centre for Drug Statistics Methodology