Oxytetracycline

Key facts

• Oxytetracycline is a tetracycline antibiotic that stops susceptible bacteria from multiplying.
• It is usually taken on an empty stomach, at least an hour before or two hours after food, milk or antacids, which block its absorption.
• Do not take oxytetracycline during pregnancy or give it to children under 8; it binds to calcium in developing teeth and bone, causing permanent yellow-grey staining and can slow bone growth.
• Oxytetracycline increases sensitivity to sunlight; use sun protection and seek care for a severe sunburn-like reaction.

What oxytetracycline treats

Oxytetracycline treats bacterial infections including acne, chest and respiratory infections, chlamydia and other sexually transmitted infections, and some skin and eye infections. It is also used for certain tick-borne and rickettsial infections.

How oxytetracycline works

Bacteria build proteins using an internal structure called a ribosome. Oxytetracycline attaches to part of the bacterial ribosome and blocks it from adding new building blocks to a growing protein chain, stopping the bacteria multiplying so the immune system can clear the infection.

Before you take it

• Do not take oxytetracycline if you are pregnant, may become pregnant, or are breastfeeding, or if you have had an allergic reaction to any tetracycline antibiotic.
• Do not give oxytetracycline to children under 8 years old except when a doctor judges the benefit outweighs the risk to developing teeth.
• Take it away from milk, antacids, calcium, iron or zinc supplements, which bind to it and stop it working.
• Tell your prescriber about liver or kidney disease and any other medicines you take, including the blood thinner warfarin, whose effect oxytetracycline can strengthen.

Side effects

Common effects include nausea, diarrhoea, and increased sensitivity to sunlight.

Seek urgent medical care for:

• Severe headache with visual disturbance, which can signal raised pressure around the brain.
• Yellowing of the skin or eyes, or dark urine.
• Severe diarrhoea, which can indicate a serious gut infection.
• Swelling of the face, lips or throat, or difficulty breathing.

Safety essentials

• Never take oxytetracycline in pregnancy or give it to a young child; the tooth and bone effects are permanent and dose-related.
• Use sunscreen and cover up outdoors, since photosensitivity reactions can be severe even with brief sun exposure.
• Take the full course as prescribed and space doses away from dairy, antacids, and mineral supplements to keep the drug working.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.