What is the recommended treatment for Lyme disease?

Treatment for Lyme Disease

Doxycycline 100 mg twice daily for 14 days is the preferred first-line treatment for early Lyme disease in adults and children ≥8 years old. 1, 2

First-Line Oral Antibiotic Regimens for Early Lyme Disease

For adults with erythema migrans or early localized disease:

• Doxycycline 100 mg orally twice daily for 14 days (range 10-21 days) is the preferred agent because it also covers potential coinfection with Anaplasma phagocytophilum 1, 2
• Amoxicillin 500 mg orally three times daily for 14-21 days is an effective alternative, particularly for pregnant or lactating women 1, 2
• Cefuroxime axetil 500 mg orally twice daily for 14-21 days is another effective oral option 1, 2

Multiple randomized controlled trials demonstrated comparable efficacy across all three regimens, with no difference in complete response rates (83.9% vs 90.3% at 30 months, P > 0.2) 1

For children:

• Children ≥8 years: Doxycycline 4 mg/kg per day in 2 divided doses (maximum 100 mg per dose) for 14 days 1
• Children <8 years: Amoxicillin 50 mg/kg per day in 3 divided doses (maximum 500 mg per dose) for 14 days 1, 2

Recent evidence suggests doxycycline is generally well-tolerated and effective in children <8 years when needed, though amoxicillin remains preferred for non-neurological manifestations 3

Treatment for Specific Manifestations

Early Neurologic Disease (meningitis or radiculopathy):

• Adults: Ceftriaxone 2 g IV once daily for 14 days (range 10-28 days) 2
• Children: Ceftriaxone 50-75 mg/kg IV daily (maximum 2 g) for 14 days 2
• Alternative parenteral options include cefotaxime 2 g IV every 8 hours or penicillin G 18-24 million units per day IV divided every 4 hours 4

Lyme Carditis:

• Either oral or parenteral antibiotic therapy for 14-21 days using the same agents as for erythema migrans 2
• Hospitalization with continuous monitoring is required for symptomatic patients, those with second- or third-degree atrioventricular block, or those with first-degree heart block with PR interval ≥30 milliseconds 2

Lyme Arthritis:

• Oral regimen (same agents as erythema migrans) for 28 days 2
• For recurrent arthritis after oral regimen, consider a second 28-day oral course or switch to parenteral therapy for 14-28 days 2

Tick Bite Prophylaxis

Single-dose doxycycline 200 mg (pediatric: 4 mg/kg for children ≥8 years) is recommended ONLY when ALL of the following criteria are met: 2

• Attached tick reliably identified as adult or nymphal Ixodes scapularis
• Estimated attachment ≥36 hours
• Prophylaxis can be started within 72 hours of tick removal

Important Administration Considerations

For doxycycline:

• Take with 8 ounces of fluid to reduce esophageal irritation 1
• Take with food to minimize gastrointestinal intolerance 1
• Patients must avoid sun exposure due to photosensitivity risk 1
• Relatively contraindicated in pregnant or lactating women 1

Critical Pitfalls to Avoid

The following antibiotics are INEFFECTIVE against B. burgdorferi and should NEVER be used: 2, 4

• First-generation cephalosporins (e.g., cephalexin)
• Fluoroquinolones
• Carbapenems
• Vancomycin
• Metronidazole
• Tinidazole
• Trimethoprim-sulfamethoxazole
• Benzathine penicillin G

Macrolide antibiotics (azithromycin, clarithromycin, erythromycin) are less effective than the three first-line regimens and should only be reserved for patients intolerant of all first-line options 1, 4

Extending treatment beyond 21 days for early disease is not supported by evidence and does not improve outcomes 1

Long-term antibiotic therapy, pulsed-dosing regimens, and combination antimicrobial therapy are strongly contraindicated due to lack of efficacy and potential for harm 2, 4

Post-Treatment Considerations

Serologic tests often remain positive for months or years after successful treatment and should NOT be used to monitor treatment response 4

Retesting should only be considered in cases of persistent objective signs of disease activity (arthritis, meningitis, neuropathy) or suspected reinfection with new erythema migrans lesions 4

For patients with persistent nonspecific symptoms following recommended treatment but without objective evidence of reinfection or treatment failure, additional antibiotic therapy is not recommended 4