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Antibiotic (Tetracycline)

Doxycycline

Brand names: Vibramycin, Efracea (low-dose)

Used in: Pneumonia COPD Cellulitis & Skin Infection

Doxycycline is a long-acting tetracycline antibiotic used for respiratory, genitourinary, skin and tick-borne infections, acne and rosacea, and as antimalarial prophylaxis.

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

It binds reversibly to the bacterial 30S ribosomal subunit, blocking attachment of aminoacyl-tRNA and so inhibiting protein synthesis, producing a bacteriostatic effect.

Prescribing in practice

  • Contraindicated in pregnancy, breastfeeding and in children under twelve because tetracyclines bind to developing bone and teeth, causing permanent discolouration and enamel hypoplasia.
  • Photosensitivity is common, so advise sun protection and avoidance of sunbeds during treatment.
  • Absorption is reduced by calcium, iron, magnesium, zinc, antacids and dairy, so separate these from dosing.

Monitoring

Routine laboratory monitoring is not usually required for short courses, but watch for photosensitivity, gastrointestinal upset and signs of oesophageal irritation.

Counselling the patient

  • Take with plenty of water while sitting or standing upright and not immediately before lying down to prevent throat and oesophageal irritation.
  • Use sunscreen and cover up, as your skin may burn more easily.
  • Complete the full course as prescribed.

Evidence & guidelines

Doxycycline is recommended across NICE antimicrobial guidance for indications including community-acquired pneumonia, chronic obstructive pulmonary disease exacerbations and chlamydia.

Reference: PHE Antibiotic Guidelines; BASHH Chlamydia Guidelines; 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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