What antibiotics are used to treat Leptospirosis?

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Last updated: May 14, 2025View editorial policy

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From the Guidelines

Penicillin and tetracycline antibiotics are the recommended treatments for leptospirosis, particularly during the bacteraemic phase. According to a study published in the Journal of Infection in 2009 1, early mild disease is generally self-limiting, and these antibiotics are thought to be effective.

Key Points to Consider

  • The non-specific nature of initial investigations means treatment should be based on suspicion
  • Patients presenting with classical symptoms and signs of Weils disease, such as jaundice, can become very unwell despite therapy and may require renal or liver support
  • A systematic review of antibiotic effectiveness in established leptospirosis showed no benefit for antibiotic treatment, but most infectious disease specialists continue to recommend antibiotics 1

Treatment Approach

  • Penicillin and tetracycline antibiotics are the primary choices for treating leptospirosis
  • The effectiveness of these antibiotics is thought to be highest during the bacteraemic phase, as noted in the study 1
  • It is essential to start treatment early, ideally within the first few days of illness, to reduce the severity and duration of symptoms
  • Patients should complete the full course of antibiotics, even if symptoms improve before completion, to ensure complete eradication of the bacteria
  • Supportive care, including hydration, is also crucial, especially in severe cases with kidney or liver involvement 1

From the Research

Antibiotics Used for Leptospirosis

The following antibiotics have been studied for the treatment of leptospirosis:

  • Penicillin: widely used for treating leptospirosis, with some studies suggesting it may cause more good than harm 2
  • Doxycycline: used in combination with ceftriaxone to treat leptospirosis, with positive outcomes reported in a case study 3
  • Ceftriaxone: used in combination with doxycycline to treat leptospirosis, with positive outcomes reported in a case study 3
  • Azithromycin: compared to doxycycline, with very uncertain evidence regarding its effectiveness 4
  • Cefotaxime: compared to doxycycline and penicillin, with very uncertain evidence regarding its effectiveness 5
  • Chloramphenicol: compared to penicillin, with very uncertain evidence regarding its effectiveness 5

Efficacy of Antibiotics for Leptospirosis

The evidence for the efficacy of antibiotics in treating leptospirosis is limited and uncertain:

  • A meta-analysis found no significant difference in mortality between penicillin and placebo 6
  • A systematic review found very low-certainty evidence for the effectiveness of antibiotics in reducing mortality, serious adverse events, and hospital stay 5
  • A review of antibiotic prophylaxis for leptospirosis found low-certainty evidence for the effectiveness of doxycycline in preventing laboratory-confirmed leptospirosis 4

Adverse Events Associated with Antibiotics for Leptospirosis

The evidence for adverse events associated with antibiotics for leptospirosis is limited and uncertain:

  • A systematic review found very low-certainty evidence for the risk of non-serious adverse events associated with antibiotics 5
  • A review of antibiotic prophylaxis for leptospirosis found very low-certainty evidence for the risk of non-serious adverse events associated with doxycycline 4

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Antibiotics for treating leptospirosis.

The Cochrane database of systematic reviews, 2000

Research

Antibiotic prophylaxis for leptospirosis.

The Cochrane database of systematic reviews, 2024

Research

Antibiotics for treatment of leptospirosis.

The Cochrane database of systematic reviews, 2024

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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