Recommended Treatment for Brucella Infections
The optimal treatment for uncomplicated brucellosis is a six-week regimen of doxycycline (100 mg twice daily) combined with streptomycin (15 mg/kg daily intramuscularly) for 2-3 weeks, as this combination has demonstrated the lowest relapse rates. 1, 2
First-Line Treatment Options
Doxycycline-Streptomycin (DOX-STR): Doxycycline 100 mg twice daily orally for 6 weeks plus streptomycin 15 mg/kg daily intramuscularly for 2-3 weeks - considered the gold standard with lowest relapse rates 1, 2, 3
Doxycycline-Rifampicin (DOX-RIF): Doxycycline 100 mg twice daily orally for 6 weeks plus rifampicin 600-900 mg daily as a single morning dose for 6 weeks - effective but with higher relapse rates than DOX-STR 4, 1, 3
Doxycycline-Gentamicin (DOX-GENT): Doxycycline 100 mg twice daily orally for 6 weeks plus gentamicin 5 mg/kg daily parenterally for 7 days - comparable efficacy to DOX-STR with the advantage of wider availability of gentamicin and shorter duration of parenteral therapy 4, 1
Second-Line Treatment Options
Trimethoprim-Sulfamethoxazole (TMP-SMX): 800+160 mg twice daily for 6 weeks - can be used as a cost-effective alternative in resource-limited settings, though with higher relapse rates (up to 46%) 4, 1
Quinolone-Containing Regimens: Ofloxacin 400 mg twice daily or ciprofloxacin 500 mg twice daily for 6 weeks - should be reserved as second or third agents in combination regimens due to higher cost and risk of promoting antimicrobial resistance 4, 1
Special Populations
Pregnant Women: Rifampicin 900 mg once daily for 6 weeks is considered the drug of choice 5
Children <8 Years Old: Rifampicin with trimethoprim-sulfamethoxazole for 45 days, or rifampicin for 45 days with gentamicin 5-6 mg/kg/day for the first 5 days 5
Complicated Brucellosis
Neurobrucellosis: Consider adding ceftriaxone to the standard regimen, or if ceftriaxone cannot be used, a combination of doxycycline and rifampicin with an aminoglycoside 6
Brucellar Spondylitis: Aminoglycoside-containing regimens may be superior to rifampicin-containing ones, and treatment duration may need to be extended beyond the standard 6 weeks 2, 6
Brucellar Endocarditis: Requires aggressive management with empirical antimicrobial selection and surgical intervention in most cases 2, 7
Treatment Outcomes and Monitoring
Relapse rates range from 5-15% even with appropriate treatment; DOX-STR has the lowest relapse rate (5.3%) compared to DOX-RIF (16%) 1, 2, 3
Relapses are usually mild and can be treated with the same regimens 1, 2
A meta-analysis showed that DOX-STR is superior to DOX-RIF for preventing relapses (OR = 3.17; CI95% = 2.05-4.91) 8
Important Considerations
In regions where brucellosis and tuberculosis coexist, consider the public health implications of using rifampicin, as this may contribute to mycobacterial resistance 1, 2
Monotherapy with doxycycline, rifampicin, or TMP-SMX has been associated with higher relapse rates and is not recommended for uncomplicated brucellosis 4, 5
Triple therapy with aminoglycoside-doxycycline-rifampicin has been studied but cannot be considered the therapy of choice until further evidence is available 8