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Antibiotic — Tetracycline

Doxycycline

Brand names: Vibramycin, Doxycycline Hyclate

Doxycycline is a tetracycline antibiotic used in obstetrics and gynaecology principally for pelvic inflammatory disease and certain sexually transmitted infections such as chlamydia.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

Clinical monograph

How it works

Inhibits bacterial protein synthesis by binding the 30S ribosomal subunit, giving a broad bacteriostatic spectrum including atypical and intracellular organisms.

Prescribing in practice

  • Contraindicated in pregnancy and avoided while breastfeeding because of the risk of dental staining and effects on developing bone in the child.
  • Often combined with other agents (such as metronidazole and a cephalosporin) in pelvic inflammatory disease regimens for broader anaerobic and gonococcal cover.
  • Absorption is reduced by calcium, iron, antacids and dairy, which should be separated from dosing.

Monitoring

Routine laboratory monitoring is not required for short courses; review clinical response and ensure partner notification and follow-up for sexually transmitted infections.

Counselling the patient

  • Take with plenty of water while sitting or standing upright to reduce the risk of oesophageal irritation.
  • Use sun protection as the skin may become more sensitive to sunlight.
  • Complete the full course and attend follow-up testing where advised.

Evidence & guidelines

Doxycycline-based regimens for pelvic inflammatory disease and chlamydia are recommended in BASHH and NICE guidance.

Reference: BASHH Chlamydia Guidelines (2018); BASHH PID Guidelines (2019); RCOG (2022); Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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