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Third-generation cephalosporin (anti-pseudomonal) Pregnancy: Limited data in pregnant women; animal studies do not indicate harmful effects. Should be prescribed in pregnancy only if the benefit outweighs the risk. Can be used during breast-feeding.

Ceftazidime

Brand names: Fortum

Ceftazidime is a third-generation parenteral cephalosporin antibacterial valued for its activity against Pseudomonas aeruginosa, used for serious Gram-negative and pseudomonal infections.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 1 to 2 g every 8 hours
Route: Intravenous (injection or infusion) or intramuscular
Frequency: Every 8 hours (or every 8 to 12 hours for complicated urinary tract infections)
Max: 9 g per day
Adults and children >=40 kg (intermittent administration): most infections (nosocomial pneumonia, bacterial meningitis, bacteraemia, bone/joint, complicated skin/soft-tissue, complicated intra-abdominal, CAPD-associated peritonitis) 1 to 2 g every 8 h; febrile neutropenia 2 g every 8 h; complicated UTI 1 to 2 g every 8 or 12 h; broncho-pulmonary infection in cystic fibrosis 100 to 150 mg/kg/day every 8 h (max 9 g/day). Continuous infusion (severe infection): loading dose 2 g then continuous infusion of 4 to 6 g every 24 h. Elderly over 80 years: daily dose should not normally exceed 3 g. TURP prophylaxis: 1 g at induction of anaesthesia plus a second dose at catheter removal.

Paediatric dose

Dose: 100 mg/kg
Route: Intravenous or intramuscular
Frequency: Per day, in three divided doses
Max: 6 g/day
Children <40 kg (infants and toddlers >2 months): 100 to 150 mg/kg/day in three divided doses (max 6 g/day) for most infections; neutropenic children 150 mg/kg/day in three divided doses (max 6 g/day). Continuous infusion (>2 months): loading dose 60 to 100 mg/kg then continuous infusion 100 to 200 mg/kg/day (max 6 g/day). Neonates and infants <=2 months: 25 to 60 mg/kg/day in two divided doses (serum half-life can be three to four times that in adults; continuous infusion not established in this age group).

Dose adjustments

Renal

Excreted unchanged by the kidneys; reduce dosage in renal impairment. Give an initial loading dose of 1 g. Maintenance (intermittent infusion, adults/children >=40 kg): CrCL 50 to 31 mL/min 1 g every 12 h; 30 to 16 1 g every 24 h; 15 to 6 0.5 g every 24 h; <5 0.5 g every 48 h. In severe infections increase the unit dose by 50% or increase the dosing frequency. Haemodialysis: repeat the maintenance dose after each haemodialysis period.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Paediatric weight-based calculator

Children <40 kg (infants and toddlers >2 months): 100 to 150 mg/kg/day in three divided doses (max 6 g/day) for most infections; neutropenic children 150 mg/kg/day in three divided doses (max 6 g/day). Continuous infusion (>2 months): loading dose 60 to 100 mg/kg then continuous infusion 100 to 200 mg/kg/day (max 6 g/day). Neonates and infants <=2 months: 25 to 60 mg/kg/day in two divided doses (serum half-life can be three to four times that in adults; continuous infusion not established in this age group).

Verify in a children's formulary

Contraindications

  • Hypersensitivity to the active substance, to any other cephalosporin or to any of the excipients
  • History of severe hypersensitivity (e.g. anaphylactic reaction) to any other type of beta-lactam antibacterial agent (penicillins, monobactams and carbapenems)

Side effects

  • Eosinophilia and thrombocytosis
  • Phlebitis or thrombophlebitis with intravenous administration
  • Diarrhoea
  • Maculopapular or urticarial rash, pruritus
  • Transient elevations in one or more hepatic enzymes; positive Coombs' test

Interactions

  • Nephrotoxic medicinal products (e.g. aminoglycosides, potent diuretics such as furosemide): concurrent high-dose use may affect renal function - monitor renal function carefully
  • Chloramphenicol: shown to be antagonistic to beta-lactams including ceftazidime - avoid the combination

Clinical monograph

How it works

It is a beta-lactam that binds penicillin-binding proteins to inhibit bacterial cell-wall synthesis, giving a bactericidal effect with strong Gram-negative and anti-pseudomonal cover.

Prescribing in practice

  • Avoid in patients with a history of immediate hypersensitivity to penicillins or other beta-lactams because of the risk of cross-reactivity.
  • It has limited Gram-positive activity, so it is often combined with other agents when staphylococcal or streptococcal cover is also needed.
  • Dose adjustment is required in renal impairment, in line with the SPC.

Monitoring

Monitor renal function and clinical response, particularly during prolonged courses or in renally impaired or critically ill patients.

Counselling the patient

  • This antibiotic is given by injection or infusion under clinical supervision.
  • Report any rash, swelling, breathing difficulty, or severe or persistent diarrhoea.

Evidence & guidelines

Ceftazidime is established in UK and NICE guidance as an option for serious Gram-negative and pseudomonal infections.

Reference: BSAC; UKHSA AMR; CF Trust; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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