Common side effect include nausea, fever, liver problems, headache, trouble sleeping, and pain at the site of infusion.[4] Severe side effects may include anaphylaxis, seizures, and Clostridioides difficile-associated diarrhea.[4] While use appears to be safe in pregnancy the medication has not been well studied in this group.[6] Doses should be adjusted in those with kidney problems.[7] Ceftazidime works by interfering with the building of the bacterial cell wall while avibactam works by preventing ceftazidime's breakdown.[4]
For many bacterial infections, it offers little or no advantage over ceftazidime monotherapy, due to the widespread expression of resistance mechanisms other than β-lactamase production. These include Haemophilus, Moraxella and Neisseria pathogens, and infections caused by Acinectobacter baumannii.[10]
The antibacterial spectrum of ceftazidime/avibactam includes nearly all Enterobacteriaceae, including ceftazidime-resistant strains. The activity of ceftazidime/avibactam against the important hospital pathogen Pseudomonas aeruginosa is variable, due to the potential presence of other resistance mechanisms in addition to β-lactamase production. Synergy was observed for avibactam with ceftazidime in Burkholderia infections.[12]
When used to treat life-threatening infections, ceftazidime/avibactam is more likely than carbapenem antibiotics to cause serious adverse events, including worsening kidney function and gastrointestinal adverse effects.[13]
Bacterial resistance to cephalosporins is often due to bacterial production of β-lactamase enzymes that deactivate these antibiotics. Avibactam inhibits some (but not all) bacterial β-lactamases. Also, some bacteria are resistant to cephalosporins by other mechanisms, and therefore avibactam doesn't work. Avibactam is not active against New Delhi metallo-β-lactamase 1 (NDM-1).[14] Avibactam inhibits Klebsiella pneumoniaecarbapenemases (KPCs), and AmpC-type β-lactamases, which are resistant to the other clinically available β-lactamases, tazobactam and clavulanic acid.[15]
^World Health Organization (2019). World Health Organization model list of essential medicines: 21st list 2019. Geneva: World Health Organization. hdl:10665/325771. WHO/MVP/EMP/IAU/2019.06. License: CC BY-NC-SA 3.0 IGO.
^Di Bella S, Giacobbe DR, Maraolo AE, Viaggi V, Luzzati R, Bassetti M, et al. (June 2021). "Resistance to ceftazidime/avibactam in infections and colonisations by KPC-producing Enterobacterales: a systematic review of observational clinical studies". Journal of Global Antimicrobial Resistance. 25: 268–281. doi:10.1016/j.jgar.2021.04.001. hdl:11368/2990131. PMID33895414. S2CID233399477.