Third-Generation Cephalosporin — Pseudomonas / Gram-Negative Infections 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, Kefadim

Ceftazidime is a third-generation cephalosporin given parenterally with notable anti-pseudomonal activity, used for serious Gram-negative infections including hospital-acquired pneumonia, febrile neutropenia and melioidosis.

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

Patient weight (kg)

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 inhibits bacterial cell-wall synthesis by binding penicillin-binding proteins and is relatively stable to many beta-lactamases, giving it strong activity against Pseudomonas aeruginosa and other Gram-negative bacilli.

Prescribing in practice

Contraindicated in cephalosporin hypersensitivity and used with caution with a history of significant penicillin or beta-lactam allergy because of potential cross-reactivity.
It has limited activity against Gram-positive organisms, so is not suitable as monotherapy where staphylococcal or streptococcal cover is needed.
Renally excreted and requires dose adjustment in renal impairment, where accumulation can cause neurotoxicity.

Monitoring

Monitor renal function, clinical response, and consider effects on full blood count and liver enzymes during prolonged therapy.

Counselling the patient

This is a hospital injectable antibiotic active against difficult Gram-negative bacteria.
Report any rash, severe diarrhoea, or breathing difficulty.
Tell staff about previous penicillin or cephalosporin allergy.

Evidence & guidelines

Ceftazidime is a long-established guideline option for anti-pseudomonal cover and is recommended in melioidosis and febrile neutropenia regimens.

Reference: ECIL Guidelines Febrile Neutropenia; IDSA Guidelines Pseudomonas; PHE Antibiotic Guidelines; 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).

Curated clinical cross-links plus same-class fallbacks.

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Pathways