Effective Administration of OPAT with Aztreonam–Avibactam in Pediatrics

Background

Osteoarticular infections following open fractures can impair bone development and prolong recovery in children. War-related injuries may involve contaminated wounds, delayed surgery, and limited microbiological resources. Treatment becomes particularly difficult when infection involves metallo-beta-lactamase-producing organisms such as NDM-producing Enterobacterales. Aztreonam-avibactam offers a potential strategy against these organisms, but pediatric experience is limited, and the drug is not approved for pediatric use.

Data Highlights

• Patient: 9-year-old girl weighing 19.3 kg

• Infection: Infectious pseudoarthrosis of the right distal tibia

• Organisms: Pseudomonas aeruginosa and ESBL- and NDM-producing Klebsiella pneumoniae

• Initial inpatient dose: 155 mg/kg/day based on the aztreonam component

• Inpatient administration: Every 6 hours as 3-hour intravenous infusions

• Home administration: Two 12-hour elastomeric pumps daily

• Treatment duration: 6 weeks

• Posttreatment follow-up: 2 months

Key Findings

• Intraoperative bone cultures obtained after removal of the tibial external fixators grew P aeruginosa and ESBL- and NDM-producing K pneumoniae.

• The K pneumoniae isolate was susceptible only to gentamicin and aztreonam-avibactam.

• Empiric intravenous vancomycin was changed to off-label aztreonam-avibactam after culture and susceptibility results became available.

• While awaiting repeat surgery, the patient transitioned to hospital-at-home-supervised OPAT.

• Caregivers received education on self-administration, intravenous-line care, warning signs, and elastomeric-device replacement.

• A transient alanine aminotransferase elevation prompted treatment interruption; therapy was safely resumed after liver enzymes normalized.

• Two months after completing treatment, the patient remained clinically stable without signs or symptoms of persistent or recurrent infection.

Clinical Implications

This case demonstrates that aztreonam-avibactam can be delivered through a monitored pediatric OPAT program using elastomeric infusion devices. It supports the drug’s potential role in selected pediatric osteoarticular infections caused by metallo-beta-lactamase-producing organisms when alternatives are limited. Because this was a single off-label use, it does not establish pediatric efficacy, safety, dosing standards, or routine treatment recommendations. Careful laboratory monitoring, multidisciplinary management, pharmacy involvement, and caregiver education are essential.

Conclusion

Off-label aztreonam-avibactam administered during hospitalization and through OPAT was feasible in this child with infectious pseudoarthrosis caused by NDM-producing K pneumoniae and P aeruginosa. Treatment was completed after temporary interruption for suspected hepatotoxicity, with no evidence of recurrent infection at short-term follow-up. Pediatric-specific studies are needed to determine optimal dosing, safety, and long-term effectiveness.

Related Resources & Content

1. Successful Use of Outpatient Parenteral Antimicrobial Therapy (OPAT) Aztreonam-Avibactam in a Pediatric Case of an Infectious Pseudoarthrosis Caused by NDM-Producing Klebsiella pneumoniae and Pseudomonas aeruginosa — Bosch-Peligero M, Codina-Jimenez C, Chaguaceda Galisteo C, et al. International Journal of Infectious Diseases. 2026;170:108840. doi:10.1016/j.ijid.2026.108840.

2. Infectious Diseases Society of America 2024 Guidance on the Treatment of Antimicrobial-Resistant Gram-Negative Infections — Tamma PD, Heil EL, Justo JA, Mathers AJ, Satlin MJ, Bonomo RA. Clinical Infectious Diseases. 2024:ciae403. doi:10.1093/cid/ciae403.

3. Delivery, Setting and Outcomes of Paediatric Outpatient Parenteral Antimicrobial Therapy: A Scoping Review — BMJ Open. 2018;8:e021603. doi:10.1136/bmjopen-2018-021603.

4. Pediatric aztreonam-avibactam trial — ClinicalTrials.gov identifier: NCT05639647.

5. Pediatric aztreonam-avibactam trial — ClinicalTrials.gov identifier: NCT06462235.