What Was Approved?
On May 29, 2026, the U.S. Food and Drug Administration approved Zaynich (cefepime and zidebactam) for adults with complicated urinary tract infections, including pyelonephritis, caused by designated susceptible bacteria.
Zaynich combines:
- Cefepime, a cephalosporin antibacterial
- Zidebactam, a beta-lactamase inhibitor and antibacterial agent
How Is Zaynich Given?
For adults with an estimated glomerular filtration rate of at least 60 mL/min, the recommended dose is:
3 grams by intravenous infusion every 8 hours for 7 to 10 days.
Each dose contains 2 grams of cefepime and 1 gram of zidebactam.
Dose adjustment is required in patients with reduced kidney function.
What Are the Main Safety Concerns?
Important warnings include:
- Serious allergic reactions, including anaphylaxis
- Neurotoxicity, particularly when cefepime dosing is not appropriately adjusted for impaired kidney function
- Clostridioides difficile-associated infection
Zaynich should not be used in patients with a history of serious hypersensitivity to its components or other beta-lactam antibacterial drugs.
What Are the Common Side Effects?
The most common adverse reactions reported in at least 2% of patients treated with Zaynich were:
- Diarrhea
- Headache
- High blood pressure
- Low potassium
Why Is Antibiotic Stewardship Important?
Zaynich should be used only for infections that are proven or strongly suspected to be caused by susceptible bacteria.
Using antibacterial medicines when they are not needed can contribute to the development of drug-resistant bacteria.
Bottom Line
Zaynich (cefepime and zidebactam) is a newly FDA-approved intravenous antibacterial treatment for certain complicated urinary tract infections, including pyelonephritis, in adults.
Because kidney function affects dosing and serious neurologic and allergic reactions can occur, treatment requires appropriate clinical monitoring.
Sources
- U.S. Food and Drug Administration (FDA) — Novel Drug Approvals for 2026.
- U.S. Food and Drug Administration (FDA) — Zaynich (cefepime and zidebactam) Prescribing Information, revised May 2026.