1320 - Drug-Induced Leukopenia During Rehabilitation: A Rare Case of Ceftriaxone-Associated Leukopenia in the Elderly

Case of an 80-year-old male with a history of OSA, HTN, AFib, hypothyroidism, and HFpEF who was admitted to inpatient rehabilitation facility following a diagnosis of critical illness myopathy. Admission labs showed normochromic normocytic anemia and thrombocytopenia, with normal white blood cell (WBC) counts. On day 6, he developed dysuria and was started on ceftriaxone 2g IV daily for a suspected complicated UTI. The next day, routine labs revealed new-onset leukopenia, which worsened by antibiotic day 7. Ceftriaxone was discontinued due to suspected drug-induced leukopenia and replaced with amoxicillin-clavulanate. WBC counts were monitored closely, showing progressive improvement. By day 12 post-ceftriaxone discontinuation, WBC levels normalized. UTI symptoms resolved fully prior to discharge. This case highlights a rare but reversible adverse effect of ceftriaxone.

Discussions:

Complicated and catheter-associated urinary tract infections are among the most common infections in hospitalized and rehabilitation patients. Ceftriaxone is frequently used for empiric therapy due to its broad-spectrum coverage and convenient once-daily dosing. However, although generally well tolerated, ceftriaxone has been associated with rare but potentially serious hematologic toxicities, including leukopenia. Drug-induced leukopenia is particularly concerning in the inpatient setting, where it may increase infection risk, delay recovery, and necessitate antibiotic changes. In rehabilitation populations, early recognition of ceftriaxone-induced leukopenia is essential to minimize complications and ensure continuity of care.

Conclusions:

This case highlights ceftriaxone-induced leukopenia, a rare but reversible adverse effect. Timely recognition of the leukopenia, discontinuation of ceftriaxone, and appropriate antibiotic substitution led to gradual hematologic recovery and uninterrupted rehabilitation progress. While ceftriaxone remains a commonly used and generally safe antibiotic in hospitalized and rehabilitation patients, clinicians should maintain a high index of suspicion for drug-induced cytopenias in the setting of new or unexplained leukopenia. Early identification and management are critical to preventing secondary infections, avoiding prolonged hospital stays, and optimizing functional recovery.