Effectiveness and Safety of Dual Versus Triple Antibiotic Therapy for Treating Brucellosis Infection: A Retrospective Cohort Study

<b>Background:</b> Brucellosis is a major zoonotic infection that warrants treatment with antibiotic therapy. Current treatment recommendations include using either dual or triple therapy with antibiotics active against brucella species. This study aims to evaluate the effectiveness and safety of dual and triple antibiotic therapy for treating brucellosis. <b>Methods:</b> This is a retrospective cohort study for patients with confirmed Brucellosis infection from 2015 to 2024. The primary outcome was the achievement of a favorable response. Secondary outcomes were treatment failure, 90-day mortality, relapse of brucella infection, hospital re-admission, and adverse drug reactions (ADRs). Baseline characteristics were reported as means with standard deviations. All the statistical tests are shown as odds ratios (ORs) with 95% confidence intervals (CIs). <b>Results:</b> In total, 966 patients were screened and 287 met the inclusion criteria: 164 patients in the dual therapy group and 123 patients in the triple therapy group. Achievement of a favorable response was not statistically different between the dual therapy and triple therapy groups; 87.3% vs. 90.5%, OR 1.2 (0.48-3.02, <i>p</i> = 0.42). No patient died in either treatment group. Treatment failure, mean duration of hospitalization, brucella relapse, hospital re-admission, and the mean time to defervescence were not statistically different between dual and triple therapy groups. Adverse drug reactions were numerically higher in the triple therapy group. <b>Conclusions:</b> Dual therapy was equally effective for the treatment of patients with brucellosis compared to the triple therapy regimens. Although not statistically significant, there more ADRs in the triple therapy group compared to those receiving dual therapy. Thus, dual antibiotic therapy is efficacious, less costly, and associated with fewer ADRs compared to triple antibiotic therapy.