Comparative Outcomes of Amoxicillin and Amoxicillin-Clavulanate in the Treatment of Acute Rhinosinusitis in Adults with Comorbidities: A Retrospective Study.

Background/

Objectives

The optimal antibiotic strategy for acute rhinosinusitis (ARS) in patients with comorbidities remains unclear. Guidelines often recommend amoxicillin-clavulanate (amx/clv) for high-risk patients, despite limited comparative evidence. This study compared ARS outcomes of patients with comorbidities receiving amoxicillin and amx/clv.

Methods

This retrospective cohort study utilized electronic medical records from the Israeli community (2012-2023). Adults aged ≥18 years with ≥1 selected comorbidity and an ARS diagnosis were categorized according to the type of antibiotic prescribed. The primary outcome was treatment failure, defined as a follow-up ARS visit with an antibiotic prescription within 30 days of the initial visit. Secondary outcomes included ARS complications, emergency room referrals, chronic or subacute sinusitis diagnosis, and 90-day mortality rates. Adjusted odds ratios were estimated using multivariable logistic regression.

Results

Of the 38,810 eligible patients, 4953 were prescribed amoxicillin, 7436 were prescribed amx/clv, and 26,421 were not prescribed antibiotics. Treatment failure rates were not significantly different when comparing amoxicillin to amx/clv or either antibiotic to no antibiotic therapy. Chronic or subacute sinusitis was more frequent with amx/clv than with amoxicillin alone. No significant intergroup differences were observed in terms of complications, emergency room referrals, or mortality rates. These findings remained consistent in a sensitivity analysis of filled prescriptions and when analyzing the outcomes of individual comorbidities separately.

Conclusions

Among adults with specified comorbidities diagnosed with ARS, the rates of treatment failure, complications, and ER referrals did not differ significantly between amoxicillin and amx/clv, supporting narrow-spectrum therapy.