Rise of the beta-lactams: a retrospective, comparative cohort of oral beta-lactam antibiotics as step-down therapy for hospitalized adults with acute pyelonephritis.

OBJECTIVE

The aim of this study was to determine if oral beta-lactam therapy is non-inferior to alternative therapy at discharge following inpatient treatment with an IV cephalosporin for acute pyelonephritis.

DESIGN

Institutional Review Board (IRB)-approved, multicenter, retrospective, non-inferiority cohort (15% non-inferiority margin).

SETTING

Six hospitals within two healthcare systems.

PATIENTS

Hospitalized patients admitted to the medical floor with acute pyelonephritis without urologic abnormalities who received cefazolin or ceftriaxone followed by step-down therapy.

METHODS

Patients were discharged with either an oral beta-lactam or an oral alternative agent (ie, fluoroquinolone or trimethoprim-sulfamethoxazole) to complete therapy. The primary objective was treatment failure defined as a composite of hospital readmission or an ED visit for a urinary cause within 30 days of discharge of the index hospitalization. Data were extracted manually from the electronic medical record.

RESULTS

A total of 211 patients were included; 122 received an oral beta-lactam and 89 received an oral alternative agent at discharge. There was no difference in 30-day treatment failure between the two groups (4.9% vs 5.6% for oral beta-lactams vs oral alternatives, respectively. Absolute difference = 0.7%; 95% CI -5.4% to 6.8%; = .82). The median length of hospital stay, number of patients treated with intravenous ceftriaxone, duration of IV therapy, and median duration of oral therapy were no different between groups.

CONCLUSIONS

In non-ICU patients admitted for pyelonephritis without urologic abnormalities, oral beta-lactams were non-inferior to oral alternatives for step-down therapy. In finding non-inferiority between the regimens, we show the feasibility of administering oral beta-lactams to complete therapy for acute pyelonephritis.