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Antibiotic — broad-spectrum

Chloramphenicol

Brand names: Chloromycetin, Optrex Infected Eyes

Adult dose

Dose: Eye drops 0.5%: 1 drop 2-hourly for 48h, then QDS for 5 days. Eye ointment 1% nocte. Systemic: 50mg/kg/day in 4 divided doses (life-threatening infection only)
Route: Topical/IV/PO
Frequency: varies

Paediatric dose

Dose: 12.5 mg/kg
Route: IV
Frequency: Every 6 hours (4 divided doses; total 50 mg/kg/day)
Max: 1 g per dose (4 g/day)
BNFc child 1 month–18 years: 12.5 mg/kg every 6 hours IV (50 mg/kg/day) for severe infection; up to 25 mg/kg every 6 h (100 mg/kg/day) for life-threatening infection (e.g. H. influenzae meningitis), reduced once response achieved. Plasma-concentration monitoring essential. Topical eye drops widely used in children >2 years. AVOID in neonates (grey baby syndrome).
Paediatric weight-based calculator

BNFc child 1 month–18 years: 12.5 mg/kg every 6 hours IV (50 mg/kg/day) for severe infection; up to 25 mg/kg every 6 h (100 mg/kg/day) for life-threatening infection (e.g. H. influenzae meningitis), reduced once response achieved. Plasma-concentration monitoring essential. Topical eye drops widely used in children >2 years. AVOID in neonates (grey baby syndrome).

Clinical pearls

  • Topical use first-line for bacterial conjunctivitis
  • Systemic use restricted to life-threatening infections (e.g. typhoid, H. influenzae meningitis where alternatives unsuitable)

Contraindications

  • History of bone marrow toxicity
  • Avoid in 3rd trimester pregnancy and neonates (grey baby syndrome)

Side effects

  • Aplastic anaemia (rare, idiosyncratic)
  • Reversible bone marrow depression
  • Optic neuritis (prolonged use)
  • Grey baby syndrome in neonates

Interactions

  • Increases warfarin, phenytoin, sulfonylurea levels (CYP2C9 inhibitor)

Monitoring

  • FBC for systemic use
  • Plasma levels in neonates

Reference: BNFc; BNF; NICE CKS; https://bnf.nice.org.uk/drugs/chloramphenicol/. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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