What is the recommended treatment regimen for Brucellosis?

Brucellosis Treatment Regimen

The optimal treatment for 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 the lowest relapse rates and highest efficacy. 1

First-Line Treatment Options

Preferred Regimen:

• Doxycycline-Streptomycin (DOX-STR) - Evidence level AI (highest recommendation)
  • Doxycycline: 100 mg twice daily orally for 6 weeks
  • Streptomycin: 15 mg/kg daily intramuscularly for 2-3 weeks 1
  • Clinical response rate of 95.4% with lowest relapse rate (4.6%) 2

Alternative First-Line Option:

• Doxycycline-Gentamicin (DOX-GENT) - Evidence level BI
  • Doxycycline: 100 mg twice daily orally for 6 weeks
  • Gentamicin: 5 mg/kg daily parenterally for 7 days 1
  • Suitable when streptomycin is unavailable or contraindicated

Second-Line Treatment Options

Doxycycline-Rifampicin (DOX-RIF):

• Doxycycline: 100 mg twice daily orally for 6 weeks
• Rifampicin: 600-900 mg daily for 6 weeks 1
• Higher relapse rate compared to DOX-STR (16% vs 5.3%) 3
• Less effective than DOX-STR with a risk ratio for treatment failure of 1.91 4

Quinolone-Rifampicin Regimens:

• Ciprofloxacin or ofloxacin plus rifampicin
• Similar efficacy to DOX-RIF but with higher relapse rates 1
• Evidence level CII 1

Trimethoprim-Sulfamethoxazole (TMP-SMX) Regimens:

• More cost-effective in developing countries
• Evidence level CII 1

Special Populations

Pregnant Women:

• Rifampicin 900 mg once daily for 6 weeks is considered the drug of choice 5
• Tetracyclines are contraindicated during pregnancy 5

Children < 8 Years:

• Preferred: Rifampicin with cotrimoxazole (trimethoprim-sulfamethoxazole) for 45 days
• Alternative: Rifampicin for 45 days with gentamicin 5-6 mg/kg/day for the first 5 days 5
• Tetracyclines are generally contraindicated for children < 8 years old 5

Treatment Duration and Follow-up

• Standard duration for uncomplicated brucellosis: 6 weeks 1
• Extended duration (3-6 months) for localized infections:
  • Endocarditis
  • Neurobrucellosis
  • Osteomyelitis 1
• Follow-up for at least 2 years after treatment to monitor for recurrence 1

Important Clinical Considerations

1. Monitoring for Relapse: Particularly important in patients treated with regimens other than doxycycline-streptomycin 1

2. Regional Considerations: In areas where brucellosis and tuberculosis coexist, rifampicin use may contribute to mycobacterial resistance 1

3. Treatment Challenges: Despite appropriate therapy, relapse rates range from 5% to 15% in uncomplicated cases 6

4. Surgical Intervention: Consider for patients with endocarditis, cerebral/epidural abscess, spleen abscess, or other antibiotic-resistant abscesses 5

5. Accessibility and Cost: Daily intramuscular injections for streptomycin may present access challenges in some settings, which may influence regimen selection 4

The DOX-STR combination should remain the first-line regimen for brucellosis treatment due to its superior efficacy and lower relapse rates compared to other regimens, despite requiring daily intramuscular injections for the streptomycin component.