FDA Approves Zerbaxa (ceftolozane/tazobactam) for Complicated Infections and Pneumonia

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FDA Published May 15, 2026 Medically reviewed May 15, 2026 DOI ↗ By Dr. Amelia Tan, PhD · Internal Medicine & Chronic Disease

Key Takeaway

Consider Zerbaxa for cIAI, cUTI, and HABP/VABP caused by susceptible pathogens, with dosing adjusted for renal function.

The FDA has approved Zerbaxa (ceftolozane/tazobactam), a combination of a cephalosporin antibacterial and a beta-lactamase inhibitor, for the treatment of complicated intra-abdominal infections (cIAI), complicated urinary tract infections (cUTI) including pyelonephritis, and hospital-acquired bacterial pneumonia and ventilator-associated bacterial pneumonia (HABP/VABP). For cIAI, Zerbaxa is used in combination with metronidazole. The approval covers adult and pediatric patients (birth to less than 18 years) for cIAI and cUTI, and adults 18 years and older for HABP/VABP. Zerbaxa should be reserved for infections proven or strongly suspected to be caused by susceptible bacteria to reduce the development of drug-resistant organisms. The recommended dosing varies by infection and renal function, with intravenous administration every 8 hours over 1 hour.

＋ Clinical Details (Mechanism · Dosing · Trial Data · Warnings)

Mechanism of Action

Ceftolozane is a cephalosporin antibacterial that inhibits bacterial cell wall synthesis. Tazobactam is a beta-lactamase inhibitor that protects ceftolozane from degradation by certain beta-lactamases.

Indication & Patient Population

Zerbaxa is indicated for: - Complicated intra-abdominal infections (cIAI) in combination with metronidazole in adult and pediatric patients (birth to less than 18 years). - Complicated urinary tract infections (cUTI), including pyelonephritis, in adult and pediatric patients (birth to less than 18 years). - Hospital-acquired bacterial pneumonia and ventilator-associated bacterial pneumonia (HABP/VABP) in adult patients 18 years and older.

Dosing & Administration

Administer all doses every 8 hours by intravenous infusion over 1 hour. For adults with CrCl >50 mL/min: cIAI 1.5 g for 4-14 days; cUTI 1.5 g for 7 days; HABP/VABP 3 g for 8-14 days. For pediatric patients with eGFR >50 mL/min/1.73 m²: cIAI and cUTI 30 mg/kg (max 1.5 g) for 5-14 days and 7-14 days, respectively. Dose adjustments are required for CrCl ≤50 mL/min.

Key Clinical Trial Data

Trial data not available in label.

Warnings & Contraindications

Not reported in label.

Place in Therapy

Zerbaxa provides a treatment option for serious infections caused by susceptible Gram-negative and Gram-positive organisms, including Pseudomonas aeruginosa. It should be used only when bacterial infection is proven or strongly suspected to minimize resistance development.

Study Details

Study typeFda approval

PublishedDec 2014

View Original Abstract ↓

1 INDICATIONS AND USAGE ZERBAXA (ceftolozane and tazobactam) is a combination of ceftolozane, a cephalosporin antibacterial, and tazobactam, a beta-lactamase inhibitor, indicated for the treatment of the following infections caused by designated susceptible microorganisms: Complicated Intra-abdominal Infections (cIAI), used in combination with metronidazole, in adult and pediatric patients (birth to less than 18 years old). ( 1.1 ) Complicated Urinary Tract Infections (cUTI), Including Pyelonephritis, in adult and pediatric patients (birth to less than 18 years old). ( 1.2 ) Hospital-acquired Bacterial Pneumonia and Ventilator-associated Bacterial Pneumonia (HABP/VABP), in adult patients 18 years and older. ( 1.3 ) To reduce the development of drug-resistant bacteria and maintain the effectiveness of ZERBAXA and other antibacterial drugs, ZERBAXA should be used only to treat or prevent infections that are proven or strongly suspected to be caused by bacteria. ( 1.4 ) 1.1 Complicated Intra-abdominal Infections ZERBAXA used in combination with metronidazole is indicated for the treatment of adult and pediatric patients (birth to less than 18 years old) with complicated intra-abdominal infections (cIAI) caused by the following susceptible Gram-negative and Gram-positive microorganisms: Enterobacter cloacae, Escherichia coli, Klebsiella oxytoca, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Bacteroides fragilis, Streptococcus anginosus, Streptococcus constellatus, and Streptococcus salivarius . 1.2 Complicated Urinary Tract Infections, Including Pyelonephritis ZERBAXA is indicated for the treatment of adult and pediatric patients (birth to less than 18 years old) with complicated urinary tract infections (cUTI), including pyelonephritis, caused by the following susceptible Gram-negative microorganisms: Escherichia coli , Klebsiella pneumoniae , Proteus mirabilis , and Pseudomonas aeruginosa . 1.3 Hospital-acquired Bacterial Pneumonia and Ventilator-associated Bacterial Pneumonia (HABP/VABP) ZERBAXA is indicated for the treatment of adult patients (18 years and older) with hospital-acquired bacterial pneumonia and ventilator-associated bacterial pneumonia (HABP/VABP), caused by the following susceptible Gram-negative microorganisms: Enterobacter cloacae , Escherichia coli , Haemophilus influenzae , Klebsiella oxytoca , Klebsiella pneumoniae , Proteus mirabilis , Pseudomonas aeruginosa , and Serratia marcescens . 1.4 Usage To reduce the development of drug-resistant bacteria and maintain the effectiveness of ZERBAXA and other antibacterial drugs, ZERBAXA should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.