What is the recommended treatment for Borrelia burgdorferi infection?

Treatment of Borrelia burgdorferi Infection

For early Lyme disease, treat with oral doxycycline 100 mg twice daily for 14 days in adults, or amoxicillin 500 mg three times daily for 14-21 days as an alternative, particularly in children under 8 years and pregnant women. 1

First-Line Oral Therapy for Early Disease

The Infectious Diseases Society of America (IDSA) guidelines establish three equally effective first-line oral regimens for uncomplicated Lyme disease 1:

• Doxycycline 100 mg twice daily (adults) or 4 mg/kg/day in 2 divided doses for children ≥8 years (maximum 100 mg per dose) 1
• Amoxicillin 500 mg three times daily (adults) or 50 mg/kg/day in 3 divided doses for children (maximum 500 mg per dose) 1
• Cefuroxime axetil 500 mg twice daily (adults) or 30 mg/kg/day in 2 divided doses for children (maximum 500 mg per dose) 1

Treatment duration is 14 days for most cases, with extension to 21 days acceptable but not required. 1 Ten-day courses are effective specifically with doxycycline, though efficacy of 10-day regimens with other agents is unknown. 1

Parenteral Therapy for Neurologic Disease

For patients with meningitis or radiculopathy, use intravenous ceftriaxone 2 g once daily for 14 days (range 10-28 days). 1 This represents the preferred parenteral regimen. 1

Alternative parenteral options include 1:

• Cefotaxime 2 g IV every 8 hours (adults) or 150-200 mg/kg/day in 3-4 divided doses for children (maximum 6 g/day)
• Penicillin G 18-24 million units/day IV divided every 4 hours (adults) or 200,000-400,000 units/kg/day for children

Important exception: Isolated cranial nerve palsy (especially seventh nerve) without meningitis can be treated with oral regimens alone. 1 Patients without clinical or laboratory evidence of meningitis may receive oral therapy rather than parenteral treatment. 1

Cardiac Manifestations

Lyme carditis can be treated with either oral or parenteral regimens for 14-21 days. 1 Parenteral therapy is recommended initially for hospitalized patients requiring cardiac monitoring, with transition to oral therapy to complete the course. 1

Lyme Arthritis

Treat Lyme arthritis with oral regimens for 28 days initially. 1 For recurrent arthritis after the first oral course, either repeat oral therapy for 14-28 days or use parenteral regimens for 14-28 days. 1

Critical Medications to Avoid

First-generation cephalosporins (e.g., cephalexin) are completely ineffective against B. burgdorferi and should never be used. 1 These agents lack in vitro activity and result in clinical failure with positive cultures demonstrating persistent infection. 1

Macrolides (azithromycin, erythromycin, clarithromycin) are significantly less effective than first-line agents and should only be used when patients cannot tolerate doxycycline, amoxicillin, and cefuroxime. 1 Patients treated with macrolides require close observation to ensure resolution. 1

Special Populations

Doxycycline should be avoided in:

• Children under 8 years of age 1
• Pregnant women 1
• Breastfeeding women 1

For these populations, amoxicillin or cefuroxime axetil are preferred alternatives. 1

Doxycycline precautions: Take with 8 ounces of fluid to reduce esophageal irritation, take with food to reduce gastrointestinal intolerance, and avoid sun exposure during therapy. 1

Post-Treatment Considerations

Most patients respond promptly and completely to appropriate antibiotic therapy. 1 Fever typically subsides within 24-48 hours after starting treatment when initiated during the first 4-5 days of illness. 1 However, patients who are more systemically ill at diagnosis may take longer to respond completely. 1

Less than 10% of patients fail to respond to initial antibiotic therapy as evidenced by objective clinical manifestations. 1 Some individuals have persistent subjective complaints despite receiving curative therapy, but this does not indicate ongoing infection. 1

Chronic symptomatic B. burgdorferi infection despite recommended treatment is highly implausible based on: (1) lack of antibiotic resistance in this genus, (2) lack of correlation between persistent symptoms and laboratory inflammation markers, and (3) diminishing antibody titers in many patients with persistent symptoms—a phenomenon not seen in any other chronic infection. 1

Serologic testing remains positive for months to years after successful treatment and cannot be used to determine cure or monitor treatment response. 2, 3 Retesting should only be considered with new objective signs of disease or suspected reinfection. 3

Extended or repeated antibiotic courses beyond recommended durations provide no benefit and are not recommended. 3, 4 Multiple controlled trials demonstrate lack of efficacy for prolonged therapy in patients with persistent subjective symptoms. 1