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Third-Generation Cephalosporin — Pseudomonas / Gram-Negative Infections Pregnancy: Safe — cephalosporins considered safe in pregnancy

Ceftazidime

Brand names: Fortum, Kefadim

Adult dose

Dose: 1–2 g IV every 8 hours; Pseudomonal infections: 2 g IV every 8 hours; Cystic fibrosis exacerbation: 2 g every 8 hours
Route: Intravenous (or IM for mild infections)
Frequency: Every 8 hours
Max: 9 g/day
One of few beta-lactams with reliable Pseudomonas aeruginosa activity. Used in febrile neutropenia, Pseudomonal pneumonia, cystic fibrosis, meningitis (gram-negative), complicated UTI. No MRSA activity. Extended infusion (4-hour) may improve PK/PD target attainment against resistant organisms.

Paediatric dose

Dose: 25–50 mg/kg mg/kg
Route: IV
Frequency: Every 8 hours
Max: 6 g/day
BNFc: neonates — 25 mg/kg every 12–24 hours (age-dependent); widely used in paediatric febrile neutropenia

Dose adjustments

Renal

CrCl 31–50: 1 g every 12 hours; CrCl 16–30: 1 g every 24 hours; CrCl 6–15: 500 mg every 24 hours; CrCl <5: 500 mg every 48 hours

Hepatic

No dose adjustment required

Paediatric weight-based calculator

BNFc: neonates — 25 mg/kg every 12–24 hours (age-dependent); widely used in paediatric febrile neutropenia

Clinical pearls

  • Ceftazidime-avibactam (Zavicefta) is a new combination agent for carbapenem-resistant gram-negatives (KPC, OXA-48, ESBL) — becoming critically important for MDR organisms
  • Pseudomonal empiric coverage in febrile neutropenia — ceftazidime or piperacillin-tazobactam are standard first-line options per ECIL guidelines
  • Neurotoxicity risk in renal failure: dose reduction essential — encephalopathy, myoclonus, seizures from beta-lactam accumulation in CNS
  • Extended infusion (4 hours) optimises time above MIC for intermediate-resistant organisms — used in specialist centres for difficult-to-treat infections

Contraindications

  • Cephalosporin hypersensitivity
  • Penicillin anaphylaxis (cross-reactivity)

Side effects

  • GI disturbance
  • Eosinophilia
  • Elevated LFTs
  • Phlebitis (IV)
  • Neurotoxicity (seizures — especially in renal failure)
  • C. difficile
  • Rash

Interactions

  • Warfarin — enhanced effect
  • Aminoglycosides — synergistic for Pseudomonas (often combined)
  • Probenecid — increases levels
  • Nephrotoxic drugs — additive if combined with aminoglycosides

Monitoring

  • Renal function (dose adjustment)
  • Neurotoxicity (confusion, myoclonus) — especially in renal failure
  • LFTs
  • FBC (eosinophilia)
  • C. difficile if diarrhoea

Reference: BNFc; BNF 90; ECIL Guidelines Febrile Neutropenia; IDSA Guidelines Pseudomonas; PHE Antibiotic Guidelines. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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