Rocky Mountain spotted fever medical therapy

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Sujit Routray, M.D. [2]

The mainstay of therapy for rocky mountain spotted fever is doxycycline. Pharmacologic therapy for Rocky Mountain spotted fever (RMSF) includes either Doxycycline or Chloramphenicol.

• Doxycycline is the mainstay of therapy for Rocky Mountain spotted fever. Use of antibiotics other than doxycycline is associated with a higher risk of fatal outcome.
• Treatment is most effective at preventing death if doxycycline is started in the first 5 days of symptoms.
• Empirical antibiotic therapy should be initiated immediately when there is a suspicion of Rocky Mountain spotted fever on the basis of clinical and epidemiologic findings.
• Treatment should not be delayed until laboratory confirmation is obtained.
• If the patient is treated within the first 4-5 days of the disease, fever generally subsides within 24-72 hours.
• Failure to respond to doxycycline argues against a diagnosis of RMSF.
• Severely ill patients may require longer periods before their fever resolves, especially if they have experienced damage to multiple organ systems.
• Preventive therapy in non-ill patients who have had recent tick bites is not recommended and may, in fact, only delay the onset of disease. ^[1]

• Rocky Mountain spotted fever^[1]

• 1. Adults

• Preferred regimen: Doxycycline 100 mg PO q12h for 7-14 days
• Note: Treatment with antibiotic agents other than doxycycline is associated with worse outcomes.

• 2. Children under 45kg

• Preferred regimen: Doxycycline 2.2 mg/kg PO q12h for 7-14 days