ceftazidimeavibactam

Ceftazidime-avibactam is a fixed‑dose antibiotic combination consisting of ceftazidime, a third‑generation cephalosporin, and avibactam, a non‑β‑lactam β‑lactamase inhibitor. It is marketed under the brand names Avycaz in the United States and Zavicefta in Europe. The combination broadens the activity of ceftazidime by inhibiting a wide range of β‑lactamases including many Ambler class A and C enzymes and some class D (such as OXA‑48‑like) enzymes. It does not inhibit metallo-β‑lactamases (class B) such as NDM, VIM, or IMP.

Ceftazidime-avibactam has activity against many Enterobacterales and Pseudomonas aeruginosa that produce β‑lactamases, including some carbapenemase producers, but resistance can still occur through mechanisms such as non‑β‑lactamase resistance, porin changes, or metallo‑β‑lactamase production. It is not universally effective against all resistant Gram‑negative pathogens.

Indications in adults include complicated intra‑abdominal infections and complicated urinary tract infections, including pyelonephritis. It is also used for hospital‑acquired pneumonia and ventilator‑associated pneumonia caused by susceptible organisms, with dosing adjusted for renal function.

The typical dosing is 2.5 g (ceftazidime 2 g and avibactam 0.5 g) given intravenously every 8 hours, infused over about 2 hours, with adjustments for renal impairment. Treatment duration depends on the infection and clinical response. Common adverse effects include gastrointestinal symptoms, nausea, diarrhea, headache, and rarely hypersensitivity reactions; there is a risk of Clostridioides difficile infection.