Treatment of Brucellosis
The recommended first-line 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), which 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 (Grade AI recommendation) 2
- 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 (Grade AI recommendation) 2, 1
- Doxycycline-Gentamicin (DOX-GENT): Doxycycline 100 mg twice daily orally for 6 weeks plus gentamicin 5 mg/kg daily parenterally for 7 days (Grade BI recommendation) 2, 1
Treatment Efficacy Comparison
- DOX-STR has demonstrated superior efficacy compared to DOX-RIF with significantly lower relapse rates (5.3% vs 16%, p=0.02) 3
- Meta-analysis shows DOX-STR is superior to DOX-RIF with an odds ratio of 3.17 (95% CI = 2.05-4.91) for treatment failure or relapse 4
- DOX-GENT has comparable efficacy to DOX-STR and offers advantages including wider availability of gentamicin and sparing streptomycin for tuberculosis treatment 2, 1
Alternative Treatment Options
- Trimethoprim-Sulfamethoxazole (TMP-SMX): 800+160 mg twice daily for 6 weeks (Grade CII recommendation) - can be used as a cost-effective alternative in certain settings 2, 1
- Quinolone-containing regimens: Ofloxacin 400 mg twice daily or ciprofloxacin 500 mg twice daily for 6 weeks (Grade CII recommendation) - should be reserved as second or third agents in combination regimens 2, 1
Special Populations
- Children under 8 years: Combination of trimethoprim-sulfamethoxazole plus rifampicin for 6 weeks is the preferred regimen 5, 6
- Pregnant women: Rifampicin 900 mg once daily for 6 weeks is considered the drug of choice 6
Treatment Duration and Monitoring
- Standard treatment duration is 6 weeks for uncomplicated brucellosis 1, 7
- Short-term treatment regimens (less than 4 weeks) have significantly higher relapse rates (22% vs 4.8%) 5
- Relapse rates range from 5-15% even with appropriate treatment and are usually mild 1, 7
Complicated Brucellosis
- Brucellar spondylitis (spinal involvement) may require extended treatment beyond the standard 6 weeks, with aminoglycoside-containing regimens showing superior efficacy 7
- Neurobrucellosis may require triple therapy and longer treatment duration 8
- Brucellar endocarditis requires aggressive management with combination antimicrobial therapy and often surgical intervention 9
Common Pitfalls and Caveats
- Monotherapy has significantly higher relapse rates (13% vs 4.8%) compared to combination therapy and should be avoided 5
- In regions where brucellosis and tuberculosis coexist, consider the public health implications of using rifampicin, as this may contribute to mycobacterial resistance 1, 7
- Gentamicin duration may need modification for optimal results (studies suggest it may be shortened to 5 days or extended to 14 days) 2
- Triple therapy should not be considered the current treatment of choice for uncomplicated brucellosis until further studies have been performed 4