Oxytetracycline

How it works

It binds reversibly to the bacterial 30S ribosomal subunit, preventing aminoacyl-tRNA binding and inhibiting protein synthesis to give a bacteriostatic effect.

Prescribing in practice

• It is contraindicated in pregnancy, breastfeeding and in children, as deposition in developing bone and teeth causes permanent staining and enamel defects.
• Absorption is reduced by milk, antacids and iron, calcium, magnesium or zinc salts, which should be separated from dosing.
• It can cause photosensitivity and should be used with caution in renal impairment, where tetracyclines may accumulate.

Monitoring

Routine monitoring is not usually required for short courses; review renal function with prolonged use or in renal impairment.

Counselling the patient

• Take it on an empty stomach with water and avoid milk, antacids or mineral supplements around the same time.
• Use sun protection as your skin may burn more easily.
• Do not take it if you are or might be pregnant or breastfeeding.

Evidence & guidelines

The contraindication in pregnancy and childhood from dental and skeletal effects is well established and documented in current prescribing references.