Treatment: Begin antibiotics ASAP
Treat Lyme disease with antibiotics as soon as the diagnosis is made. Early treatment hastens relief from symptoms and halts progression of later stages of the disease. The preferred antibiotics for early localized disease are doxycycline 100 mg orally twice daily; amoxicillin 500 mg orally 3 times a day; or cefuroxime axetil 500 mg orally twice a day (TABLE 1).10 Cefuroxime axetil is also appropriate if EM can’t be clearly distinguished from bacterial cellulitis. Reserve intravenous (IV) regimens for patients with more serious presentations (eg, neurologic symptoms and symptomatic cardiac disease) and for those with refractory Lyme arthritis (TABLE 2).10
Macrolides are not recommended as first-line therapy for early Lyme disease because they are less effective.10 However, macrolides may be used with patients unable to take the preferred antibiotics. Because there have been intermittent shortages of doxycycline, minocycline—another second-generation tetracycline with a similar chemical structure and antibacterial action—has been proposed as an alternative treatment.15
Ceftriaxone IV is preferred especially for patients presenting with an AV block or myopericarditis associated with early Lyme disease. The recommended course of treatment is usually 14 days. A temporary pacemaker may be required for patients with advanced blocks. Oral antibiotics may be started as soon as the AV block is resolved, or for outpatient therapy.
For adults who have early Lyme disease with acute neurologic manifestations such as meningitis or radiculopathy, IV antibiotics for 14 days are recommended. Cefotaxime has efficacy similar to ceftriaxone but requires multiple doses a day, making the latter the preferred treatment. Penicillin G 18 to 24 million units per day, divided into doses given every 4 hours, is also a satisfactory alternative.10,16 The American Academy of Neurology states that no definitive data exist to establish superiority, or lack thereof, of either oral or parenteral treatment.17
