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3rd Generation Cephalosporin Pregnancy: Compatible — widely used for maternal infections in pregnancy

Ceftriaxone

Brand names: Rocephin

Adult dose

Dose: Meningitis: 2–4 g IV OD. Community-acquired pneumonia: 1–2 g IV OD. Septicaemia: 2–4 g IV OD. Gonorrhoea: 1 g IM single dose.
Route: IV or IM
Frequency: Once daily (IV); single dose (gonorrhoea)
Max: 4 g/day
Long half-life allows once daily dosing. Do NOT give with calcium-containing IV fluids in neonates (fatal precipitation). Biliary sludge with prolonged use.

Paediatric dose

Dose: 50 mg/kg
Route: IV or IM
Frequency: Once daily (OD) or BD for meningitis
Max: 4000 mg/day
Concentration: 100 mg/ml
BNF for Children: standard 50–80 mg/kg OD IV/IM (max 4 g/day). Calculator uses 50 mg/kg (standard dose). Meningitis: 80–100 mg/kg/day in 1–2 doses. Neonates: do NOT co-administer with IV calcium (precipitation — potentially fatal). Source: BNF for Children 2024; NICE Bacterial Meningitis Guidelines

Dose adjustments

Renal

No dose adjustment required (biliary excretion predominates)

Hepatic

Reduce dose in combined severe renal AND hepatic impairment (maximum 2 g/day)

Paediatric weight-based calculator

BNF for Children: standard 50–80 mg/kg OD IV/IM (max 4 g/day). Calculator uses 50 mg/kg (standard dose). Meningitis: 80–100 mg/kg/day in 1–2 doses. Neonates: do NOT co-administer with IV calcium (precipitation — potentially fatal). Source: BNF for Children 2024; NICE Bacterial Meningitis Guidelines

Clinical pearls

  • Meningococcal disease: 2 g IV STAT if suspected bacterial meningitis (give before LP if delay expected)
  • Neonatal caution: co-administration with IV calcium solutions causes precipitation in lung/kidneys — potentially fatal; use different lines and flush between
  • Covers most community-acquired organisms; limited against Pseudomonas — use piperacillin-tazobactam or carbapenems for Pseudomonal coverage
  • Once daily dosing — concentration-dependent killing; excellent cerebrospinal fluid penetration

Contraindications

  • Premature neonates or neonates with hyperbilirubinaemia (displaces bilirubin — kernicterus risk)
  • Concurrent IV calcium solutions in neonates

Side effects

  • Diarrhoea/C. difficile
  • Biliary sludge (especially in children)
  • Cephalosporin allergy reactions
  • Coombs positivity
  • Elevated LFTs
  • Thrombocytopenia (rare)

Interactions

  • Oral anticoagulants (warfarin) — increased INR
  • Oral calcium or calcium-containing IV fluids — precipitation in neonates

Monitoring

  • Renal function (with prolonged use)
  • LFTs
  • FBC (thrombocytopenia)
  • Biliary USS (long-term use — biliary sludge)

Reference: BNFc; BNF; NICE Bacterial Meningitis Guidelines; BASHH STI Guidelines. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.