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Cephalosporin + beta-lactamase inhibitor Pregnancy: Animal studies with ceftazidime do not indicate direct or indirect harmful effects with respect to pregnancy, embryonal/foetal development, parturition or postnatal development; animal studies with avibactam have shown reproductive toxicity without evidence of teratogenic effects. Ceftazidime/avibactam should only be used during pregnancy if the potential benefit outweighs the possible risk. Breast-feeding: ceftazidime is excreted in human milk in small quantities and it is unknown whether avibactam is excreted; a risk to newborns/infants cannot be excluded.

Ceftazidime with avibactam

Brand names: Zavicefta

Ceftazidime with avibactam is a fixed-dose intravenous antibiotic combining an anti-pseudomonal cephalosporin with the inhibitor avibactam, indicated for complicated intra-abdominal and urinary tract infections, hospital-acquired pneumonia and infections by aerobic Gram-negative organisms with limited treatment options.

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: 2 g/0.5 g (ceftazidime 2 g with avibactam 0.5 g)
Route: Intravenous infusion over 2 hours
Frequency: Every 8 hours
UK SPC (Zavicefta 2 g/0.5 g powder for concentrate for solution for infusion), adults with estimated creatinine clearance greater than 50 mL/min. The same 2 g/0.5 g every 8 hours over 2 hours applies to every licensed indication; only the duration differs — complicated intra-abdominal infection (cIAI) 5 to 14 days; complicated urinary tract infection including pyelonephritis (cUTI) 5 to 10 days (the total duration shown may include intravenous therapy followed by appropriate oral therapy); hospital-acquired pneumonia including ventilator-associated pneumonia (HAP/VAP) 7 to 14 days; bacteraemia associated with, or suspected to be associated with, any of these infections — duration in accordance with the site of infection; infections due to aerobic Gram-negative organisms in patients with limited treatment options — duration guided by the severity of the infection, the pathogen(s) and the patient's clinical and bacteriological progress. There is very limited experience with use for more than 14 days. COMBINATION USE: to be used with metronidazole when anaerobic pathogens are known or suspected to be contributing, and with an agent active against Gram-positive pathogens when these are known or suspected to be contributing. It is recommended that Zavicefta be used to treat infections due to aerobic Gram-negative organisms in adults and paediatric patients from birth with limited treatment options only after consultation with a physician experienced in the management of infectious diseases. ELDERLY: no dosage adjustment required.

Paediatric dose

Dose: 50 mg/kg
Route: Intravenous infusion over 2 hours
Frequency: Every 8 hours
Max: 2 g/0.5 g (ceftazidime/avibactam) per dose
dosePerKg refers to the CEFTAZIDIME component — ceftazidime/avibactam is a fixed 4:1 combination and the SPC's dose recommendations are based on the ceftazidime component only; the matching avibactam dose is 12.5 mg/kg. UK SPC, paediatric patients with estimated CrCl greater than 50 mL/min/1.73 m2 (Schwartz bedside formula): 6 months to less than 18 years — 50 mg/kg / 12.5 mg/kg to a maximum of 2 g/0.5 g every 8 hours over 2 hours; 3 months to less than 6 months — 40 mg/kg / 10 mg/kg every 8 hours (limited experience). Less than 3 months (patients with serum creatinine at or below the upper limit of normal for age): full-term neonates and infants over 28 days to less than 3 months — 30 mg/kg / 7.5 mg/kg every 8 hours; birth to 28 days or less — 20 mg/kg / 5 mg/kg every 8 hours; preterm infants (less than 37 weeks gestation) over 44 to less than 53 weeks postmenstrual age — 30 mg/kg / 7.5 mg/kg every 8 hours; 31 to 44 weeks or less postmenstrual age — 20 mg/kg / 5 mg/kg every 8 hours; 26 to less than 31 weeks postmenstrual age — 20 mg/kg / 5 mg/kg every 12 hours (this band is based on pharmacokinetic modelling only). Durations as for adults (cIAI 5-14 days, cUTI 5-14 days, HAP/VAP 7-14 days). Patients studied from 3 to 12 months of age were full term (37 weeks gestation or more). Verify the paediatric regimen against a children's formulary before use.

Dose adjustments

Renal

Adults with estimated CrCl 50 mL/min or less (Cockcroft-Gault), all doses infused over 2 hours: CrCl 31-50 mL/min — 1 g/0.25 g every 8 hours; CrCl 16-30 mL/min — 0.75 g/0.1875 g every 12 hours; CrCl 6-15 mL/min — every 24 hours; end-stage renal disease including on haemodialysis — every 48 hours. (In the flattened SPC table the dose 0.75 g/0.1875 g is stated once and spans the 16-30, 6-15 and end-stage renal disease rows — confirm against the SPC table before publishing.) These recommendations are based on pharmacokinetic modelling. Ceftazidime and avibactam are removed by haemodialysis. Close monitoring of estimated creatinine clearance is advised, since it can change quickly early in treatment; neurological sequelae (tremor, myoclonus, non-convulsive status epilepticus, convulsion, encephalopathy and coma) have been reported with ceftazidime when the dose was not reduced in renal impairment.

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

dosePerKg refers to the CEFTAZIDIME component — ceftazidime/avibactam is a fixed 4:1 combination and the SPC's dose recommendations are based on the ceftazidime component only; the matching avibactam dose is 12.5 mg/kg. UK SPC, paediatric patients with estimated CrCl greater than 50 mL/min/1.73 m2 (Schwartz bedside formula): 6 months to less than 18 years — 50 mg/kg / 12.5 mg/kg to a maximum of 2 g/0.5 g every 8 hours over 2 hours; 3 months to less than 6 months — 40 mg/kg / 10 mg/kg every 8 hours (limited experience). Less than 3 months (patients with serum creatinine at or below the upper limit of normal for age): full-term neonates and infants over 28 days to less than 3 months — 30 mg/kg / 7.5 mg/kg every 8 hours; birth to 28 days or less — 20 mg/kg / 5 mg/kg every 8 hours; preterm infants (less than 37 weeks gestation) over 44 to less than 53 weeks postmenstrual age — 30 mg/kg / 7.5 mg/kg every 8 hours; 31 to 44 weeks or less postmenstrual age — 20 mg/kg / 5 mg/kg every 8 hours; 26 to less than 31 weeks postmenstrual age — 20 mg/kg / 5 mg/kg every 12 hours (this band is based on pharmacokinetic modelling only). Durations as for adults (cIAI 5-14 days, cUTI 5-14 days, HAP/VAP 7-14 days). Patients studied from 3 to 12 months of age were full term (37 weeks gestation or more). Verify the paediatric regimen against a children's formulary before use.

Verify in a children's formulary

Contraindications

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

Side effects

  • Coombs direct test positive (very common, and one of the three most common reactions occurring in at least 5% of patients)
  • Nausea and diarrhoea (common; usually mild or moderate in intensity) — also vomiting and abdominal pain
  • Candidiasis including vulvovaginal and oral candidiasis; eosinophilia, thrombocytosis (common)
  • Headache, dizziness (common); rash maculo-papular, urticaria, pruritus (common)
  • Serious/uncommon or rare — Clostridioides difficile colitis and pseudomembranous colitis, thrombocytopenia, neutropenia, leukopenia, anaphylactic reaction, acute kidney injury, tubulointerstitial nephritis, and (frequency not known) Stevens-Johnson syndrome, toxic epidermal necrolysis, DRESS, acute generalised exanthematous pustulosis and Kounis syndrome

Interactions

  • Probenecid — inhibits OAT1/OAT3 uptake of avibactam by 56% to 70% in vitro and may decrease its elimination; co-administration is not recommended (US labelling; the UK SPC §4.5 was not captured in this bundle)
  • Laboratory tests — ceftazidime may cause a false-positive urinary glucose reaction with some methods; use tests based on enzymatic glucose oxidase reactions. A positive direct Coombs test is a common finding on treatment

Clinical monograph

How it works

Ceftazidime binds penicillin-binding proteins to disrupt cell-wall synthesis while avibactam protects it from hydrolysis by serine beta-lactamases such as ESBLs, AmpC, KPC and OXA-48-type enzymes; it has no activity against metallo-beta-lactamases.

Prescribing in practice

  • Use under specialist guidance for resistant Gram-negative infections, recognising it does not cover metallo-beta-lactamase-producing organisms, so susceptibility should guide therapy.
  • Avoid in significant hypersensitivity to either component or other cephalosporins, with caution in broader beta-lactam allergy.
  • Dose must be reduced in renal impairment as both components are renally eliminated.

Monitoring

Monitor renal function to guide dosing together with clinical and microbiological response and signs of Clostridioides difficile-associated diarrhoea.

Counselling the patient

  • This is a hospital intravenous antibiotic reserved for serious resistant infections.
  • Report new or worsening diarrhoea, rash, or breathing difficulty.
  • Mention any previous penicillin or cephalosporin allergy.

Evidence & guidelines

Its licensed indications are supported by the phase 3 RECLAIM, RECAPTURE and REPROVE trials in intra-abdominal, urinary and nosocomial pneumonia infections.

Reference: NICE TA836; BSAC; UKHSA AMR; SmPC; 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.