Efficacy of a 14-day course of amoxicillin for patients with erythema migrans.

Although a 14-day treatment course with amoxicillin is in wide clinical usage to treat early Lyme disease, only a few published studies exist to validate its efficacy and safety, with none in the United States. In this study, we reviewed the records of 24 prospectively followed adult patients with erythema migrans who were prescribed a 14-day course of amoxicillin, 500 mg 3 times daily. Treatment with amoxicillin was well tolerated and uniformly successful in resolving the erythema migrans skin lesion and in preventing the development of an objective neurologic, cardiac, or rheumatologic manifestation. Although the study was relatively small and only involved a single center, the findings provide additional evidence that a 14-day course of 500 mg amoxicillin given 3 times per day is highly effective therapy for patients with early Lyme disease.