Extended Antibiotic Therapy for Lyme Disease: What Doctors Are Prescribing

Extended antibiotic therapy for Lyme disease is more common in clinical practice than guidelines suggest. While the Infectious Diseases Society of America (IDSA) recommends a maximum of 21 days of antibiotics, the International Lyme and Associated Diseases Society (ILADS) supports individualized treatment based on patient response. :contentReference[oaicite:0]{index=0}

This raises an important question: what are physicians actually doing in real-world practice?

A study by Tseng and colleagues, published in Clinical Infectious Diseases, examined insurance claims data to evaluate how Lyme disease is treated across the Northeastern United States.

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Study Design and Real-World Scope

The study analyzed insurance claims from Lyme disease patients across 14 high-prevalence states between 2010 and 2012, including Connecticut, New York, Pennsylvania, and Massachusetts.

Unlike many clinical studies, this analysis was not restricted to patients meeting CDC two-tier testing criteria.

This distinction is important because standard testing—ELISA followed by Western blot—has known sensitivity limitations, particularly in early or complex cases.

In one study, only one-third of well-characterized Lyme disease patients met CDC diagnostic criteria.

This broader inclusion provides a more realistic picture of how Lyme disease is treated in everyday practice.

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Extended Antibiotic Use in Lyme Disease

The study found that extended antibiotic therapy is not uncommon:

• 18% of patients were treated for more than five weeks
• The average treatment duration was 86 days
• Treatment ranged from 35 to 404 days

Nearly half of patients (48.8%) were prescribed more than two antibiotics.

Common medications included:

• Doxycycline (74.4%)
• Azithromycin (11.5%)
• Amoxicillin and cefuroxime

Many patients required adjustments in therapy:

• 43% were switched between antibiotics
• 18% received combination therapy

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Who Is Prescribing Extended Therapy?

A small group of physicians (3%) accounted for more than 20% of extended antibiotic prescriptions.

However, most extended therapy (80%) was prescribed by hundreds of additional clinicians.

This suggests that extended treatment is not limited to a small number of outliers—it reflects broader clinical practice patterns.

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The Gap Between Guidelines and Practice

The study did not address why nearly 500 physicians prescribed treatment beyond guideline limits.

It also did not explore the role of individualized care or shared decision making.

The ILADS evidence-based guidelines emphasize that Lyme disease patients are heterogeneous and require personalized risk–benefit assessment.

“The clinical population of patients with persistent manifestations of Lyme disease is heterogeneous; therefore, treatment decisions should be individualized based on disease severity, response to therapy, tolerance of side effects, and patient preferences.”

This highlights a clear gap between standardized guidelines and real-world clinical decision-making.

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Clinical Implications

Medical societies continue to debate optimal treatment duration for Lyme disease.

In the absence of consensus, clinicians must rely on clinical judgment and patient-centered decision making.

This study demonstrates that extended and combination antibiotic therapy is already widely used in practice—reflecting the complexity of Lyme disease and the limitations of a one-size-fits-all approach.

The gap between guidelines and clinical practice also raises broader ethical questions about how best to care for patients when standard protocols fall short.

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Sources

1. Wormser GP et al. Clin Infect Dis. 2006.
2. Tseng YJ et al. Clin Infect Dis. 2015.
3. Molins CR et al. Clin Infect Dis. 2015.
4. Cameron DJ et al. Expert Rev Anti Infect Ther. 2014.

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Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.

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