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.