Ceftazidime with Avibactam

Zavicefta® is a new injectable cephalosporin formulation available in Australia. This product combines the broad-spectrum antibiotic, ceftazidime with the β-lactamase inhibitor, avibactam.

Ceftazidime is one of a limited range of antibiotics with antipseudomonal activity. However, the 2019 AURA Report (Antimicrobial Use and Resistance in Australia) demonstrates that resistance amongst Pseudomonas aeruginosa to ceftazidime has increased from 4.4% of isolates in 2014 to 5.1% in 2017. Avibactam inhibits many of the bacterial enzymes known to inactivate ceftazidime. This extends its spectrum of activity to cover a variety of multi-drug resistant Gram-negative bacteria. However, the formulation has little or no activity against most Gram-positive organisms and anaerobes. Additional agents should be used when such pathogens are known or suspected to be contributing to the infectious process.

Zavicefta® is indicated for the treatment of complicated intra-abdominal infection (in combination with metronidazole), complicated urinary tract infection, and hospital-acquired pneumonia. Ceftazidime and avibactam are both excreted into the urine unchanged; dose adjustment is recommended in moderate and severe renal impairment. The most commonly reported adverse effects are nausea and diarrhoea, which is usually mild to moderate in severity. Clostridium difficile-associated diarrhoea has been reported and should be considered if diarrhoea occurs during, or several weeks after finishing, therapy.

Broad-spectrum antibiotics such as ceftazidime increase the risk of colonisation with antibiotic-resistant microorganisms. They should, therefore, be used judiciously.