What is the recommended antibiotic treatment regimen for early localized Lyme disease in adults?

Guideline-aligned answer with reasoning, red flags and references. Clinically reviewed by Dr Kola Tytler MBBS CertHE MBA MRCGP.

Posted: 14 August 2025Updated: 14 August 2025 Guideline-Aligned (High Confidence) Clinically Reviewed
Dr Kola Tytler MBBS CertHE MBA MRCGPClinical Lead • iatroX

Recommended antibiotic treatment regimen for early localized Lyme disease in adults:

For adults diagnosed with early localized Lyme disease presenting with erythema migrans and/or non-focal symptoms, the first-line treatment is oral doxycycline 100 mg twice daily or 200 mg once daily for 21 days.

If doxycycline is unsuitable, the first alternative is oral amoxicillin 1 g three times daily for 21 days.

The second alternative, if both doxycycline and amoxicillin are unsuitable, is oral azithromycin 500 mg once daily for 17 days.

Note: Azithromycin should not be used in people with cardiac abnormalities associated with Lyme disease due to its effect on the QT interval.

Educational content only. Always verify information and use clinical judgement.