Doxycycline Plus Trimethoprim-Sulfamethoxazole versus Doxycycline plus Rifampicin in Treatment of Brucellosis: A Randomized Controlled Trial

Background and aim Brucellosis is one of the most common endemic zoonotic diseases that have large animal and human burden. Many regimens of drug combinations are used for a variable period (at least 6 weeks). Rifampicin with doxycycline is one of the most used combinations. In this respect, we aimed to compare between the efficacy of two different combinations: trimethoprim-sulfamethoxazole combined with doxycycline (TMX-Doxy) versus rifampicin combined with doxycycline (Rif-Doxy). Patient and methods Between June 2020 and January 2022, 100 patients with brucellosis were included. Half of them (50 patients) received TMX-Doxy, whereas the other half (50 patients) received Rif-Doxy for 6 weeks. Follow-up was done during the treatment course and 6 months after the end of treatment to detect successfully treated cases, failed-to-treat cases, and relapsed cases. Results The success rates of both used drug regimens were comparable, with the rate of success of TMX-Doxy combination being 90%, whereas it was 94% in the RIF-Doxy group (P=0.23). The failure rate was 4% in the TMX-Doxy group and 2% in the RIF-Doxy group (P=0.31). Relapse of brucellosis was recorded in 6% of patients in the TMX-Doxy group, whereas it was 4% of patients in the RIF-Doxy group (P=0.32). The adverse effects of both drug combinations were mild and self-limited, and none of the enrolled patients needed to stop treatment. Conclusion Combination of TMX-Doxy is effective, safe, and not inferior to the more used RIF-Doxy combination.