WEDNESDAY, April 22, 2026 (HealthDay News) -- For adults with acute sinusitis treated in the outpatient setting, there is no difference in treatment failure with standard-dose amoxicillin-clavulanate or standard-dose amoxicillin, according to a study published online April 18 in the Journal of the American Medical Association to coincide with the annual European Society of Clinical Microbiology and Infectious Diseases Global Congress, held from April 17 to 21 in Munich.
Timothy J. Savage, M.D., M.P.H., from Brigham and Women's Hospital in Boston, and colleagues compared the risk for treatment failure and adverse events between standard-dose amoxicillin-clavulanate versus standard-dose amoxicillin for adults aged 18 to 64 years with outpatient acute sinusitis.
The full cohort included 521,244 adults; there were 234,608 patients after propensity score matching (117,304 in each group). The researchers found that 3.1 percent of patients had treatment failure and 0.03 percent required an emergency department or inpatient encounter. The risk for treatment failure did not differ between the amoxicillin-clavulanate and amoxicillin groups (3.0 versus 3.1 percent); this finding was consistent across sensitivity analyses. Antibiotic-associated adverse events did not differ between the groups (1.3 versus 1.2 percent). Higher risks for secondary infections were seen for amoxicillin-clavulanate versus amoxicillin, including yeast infections (1.1 versus 0.8 percent) and Clostridioides difficile infections (0.04 versus 0.02 percent).
"We found no observed benefit to using amoxicillin-clavulanate, which supports standard‑dose amoxicillin as the preferred choice for adults with uncomplicated acute sinusitis," Savage said in a statement.
Two authors disclosed ties to the biopharmaceutical industry.