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Tetracycline Antibiotic Pregnancy: CONTRAINDICATED — tetracycline class; causes dental discolouration and bone deposition in fetus; use macrolide (erythromycin) as alternative in pregnancy

Minocycline

Brand names: Minocin, Aknemin

Adult dose

Dose: Acne: 100 mg once daily (modified-release preferred) or 50 mg twice daily; Rosacea: 40 mg once daily (sub-antimicrobial MR — Efracea); Perioral dermatitis: 100 mg once daily for 8 weeks
Route: Oral
Frequency: Once or twice daily (indication-dependent)
Max: 200 mg/day
Take with food to reduce GI upset; modified-release formulation (Minocin MR) achieves lower peak levels with equivalent efficacy — preferred to reduce vestibular side effects; minimum 8-week course for acne assessment

Paediatric dose

Dose: Not recommended <12 years (dental discolouration) N/A/kg
Route: N/A
Frequency: N/A
Max: N/A
If used ≥12 years: 100 mg once daily; consult BNFc

Dose adjustments

Renal

Use with caution in renal impairment — accumulation risk; prefer doxycycline if significant impairment

Hepatic

Use with caution in hepatic impairment — hepatotoxicity risk

Paediatric weight-based calculator

If used ≥12 years: 100 mg once daily; consult BNFc

Clinical pearls

  • BAD acne guideline: minocycline and doxycycline have equivalent efficacy for acne — doxycycline is preferred in UK practice due to minocycline's unique side-effect profile (drug-induced lupus, skin pigmentation, vestibular effects); however, modified-release minocycline (Minocin MR) has improved tolerability
  • Drug-induced lupus (DIL): MHRA warning for prolonged minocycline use — presents with arthralgia, rash, positive ANA; improves after stopping; ANA should be checked if patient develops lupus-like symptoms during prolonged treatment
  • Skin pigmentation: blue-grey discolouration of skin, teeth, bones, and internal organs (thyroid, liver) — occurs with prolonged use (>1 year); partially reversible on stopping but may persist; inform patients
  • Vestibular side effects: minocycline's high lipophilicity enables CNS penetration — dizziness, vertigo, ataxia in up to 15% patients; modified-release formulation reduces peak levels and vestibular symptoms; usually resolves on stopping
  • Rosacea sub-antimicrobial dose (Efracea 40 mg MR): specifically licensed for rosacea in the UK; below the MIC for most bacteria — anti-inflammatory (MMP inhibition) without antibiotic selection pressure; reduces resistance concerns

Contraindications

  • <12 years (teeth/bone deposition)
  • Pregnancy and breastfeeding (fetal teeth/bone effects)
  • Severe renal impairment
  • Known hypersensitivity to tetracyclines

Side effects

  • Vestibular disturbance (dizziness, vertigo — class distinctive for minocycline vs doxycycline)
  • Nausea
  • Skin pigmentation (blue-grey — prolonged use)
  • Drug-induced lupus (MHRA warning — prolonged use)
  • Hepatotoxicity
  • Benign intracranial hypertension (avoid with retinoids)
  • Photosensitivity (less than doxycycline)

Interactions

  • Retinoids (isotretinoin, alitretinoin) — avoid combination; additive benign intracranial hypertension risk
  • Antacids, milk, iron — chelation reduces absorption; separate by ≥2 hours
  • Warfarin — tetracyclines potentiate anticoagulant effect; monitor INR

Monitoring

  • Acne response at 8-12 weeks
  • ANA if lupus-like symptoms develop
  • LFTs (prolonged use)
  • Skin pigmentation assessment (prolonged use)
  • Vestibular symptoms (each visit)

Reference: BNFc; BNF 90; BAD Acne Guidelines (2017, updated 2021); BAD Rosacea Guidelines (2021); MHRA minocycline drug-induced lupus warning; NICE CKS Acne Vulgaris; SPC Minocin MR. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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