What is the typical treatment regimen for a patient diagnosed with Brucella?

Brucellosis Treatment

For uncomplicated brucellosis in adults, the optimal regimen is doxycycline 100 mg twice daily orally for 6 weeks combined with streptomycin 15 mg/kg daily intramuscularly for 2-3 weeks, as this combination achieves the lowest relapse rates. 1, 2

First-Line Treatment Regimens

The treatment approach depends on disease complexity and patient-specific contraindications:

Preferred Regimen (Lowest Relapse Rate)

• Doxycycline-Streptomycin: Doxycycline 100 mg twice daily orally for 6 weeks PLUS streptomycin 15 mg/kg daily intramuscularly for 2-3 weeks 1, 2
• This combination demonstrates superior efficacy with relapse rates of 5-15%, which is approximately 5% lower than alternative regimens 1, 2

Alternative First-Line Options

• Doxycycline-Gentamicin: Doxycycline 100 mg twice daily orally for 6 weeks PLUS gentamicin 5 mg/kg daily parenterally as a single dose for 7 days 1, 2

  • The WHO recommends this as first-line with comparable efficacy to doxycycline-streptomycin 1
  • Gentamicin offers the advantage of wider availability and shorter parenteral therapy duration (7 days vs 14-21 days) 1
  • Critical dosing note: Use weight-based dosing (5 mg/kg daily); fixed 500 mg dosing is not recommended 1

• Doxycycline-Rifampicin: Doxycycline 100 mg twice daily orally for 6 weeks PLUS rifampicin 600-900 mg daily as a single morning dose for 6 weeks 1, 2

  • This is considered a second-choice regimen due to higher relapse rates compared to aminoglycoside-containing regimens 2
  • Important caveat: In regions where tuberculosis coexists with brucellosis, avoid rifampicin when possible to prevent mycobacterial resistance 1, 2

Second-Line Treatment Options

• Doxycycline-Trimethoprim-Sulfamethoxazole: Doxycycline plus TMP-SMX 800+160 mg twice daily for 6 weeks 1

  • Cost-effective alternative in resource-limited settings with response rates above 90% 1
  • May also be used as a third agent in complicated cases 1

• Quinolone-Containing Regimens: Reserve ofloxacin or ciprofloxacin as second or third agents in combination therapy 1

  • Higher cost and increased risk of antimicrobial resistance 1

Special Populations

Children Under 8 Years Old

• Preferred regimen: Rifampicin 900 mg once daily PLUS trimethoprim-sulfamethoxazole for 6 weeks 3, 4
• Alternative: Rifampicin for 6 weeks PLUS gentamicin 5-6 mg/kg/day for the first 5-7 days 3, 5
• Tetracyclines are contraindicated due to dental staining and bone growth effects 3, 4

Pregnant Women

• Drug of choice: Rifampicin 900 mg once daily for 6 weeks 3, 4
• Tetracyclines are contraindicated in pregnancy 3, 4

Complicated Brucellosis

Brucellar Spondylitis (Spinal Involvement)

• Evaluate with MRI when back pain is present, as this may indicate spinal involvement requiring extended therapy 2, 6
• Treatment duration: Extend to 12 weeks (3 months) minimum 2
• Preferred regimens: Aminoglycoside-containing regimens may be superior to rifampicin-containing ones 2, 6
• If cervical spine involvement, immobilization is crucial to prevent devastating neurological complications 6

Neurobrucellosis

• Consider doxycycline and rifampicin with an aminoglycoside (preferably gentamicin over streptomycin) 6
• Treatment duration typically 12-24 weeks 2

Brucellar Endocarditis

• High mortality complication requiring aggressive management 2
• Combination of parenteral aminoglycosides with multiple oral agents 7
• Surgical intervention required in most cases 2, 4

Critical Treatment Principles

Duration Matters

• Standard duration is 6 weeks for uncomplicated cases 1, 2
• Shorter durations (3 weeks) are inadequate and associated with unacceptably high relapse rates of 22% 2, 5
• Monotherapy increases relapse risk to 13% compared to 4.8% with combination therapy 5

Monitoring and Relapse

• Even with appropriate treatment, relapse rates range from 5-15% 1, 2
• Relapses are usually mild and respond to the same treatment regimens 1, 2
• Patients should be monitored for recurrence of symptoms during and after treatment completion 1

Common Pitfalls to Avoid

• Do not use monotherapy except in carefully selected low-risk patients with no focal lesions 8
• Do not shorten treatment duration below 6 weeks for uncomplicated cases 2
• Do not use fixed-dose gentamicin (500 mg); always use weight-based dosing (5 mg/kg) 1
• Do not overlook back pain as it may represent spondylitis requiring extended treatment 2
• Do not use rifampicin indiscriminately in TB-endemic areas due to resistance concerns 1, 2