Treatment of tick-borne diseases

To review the data regarding the pharmacotherapy of Lyme disease, Rocky Mountain spotted fever (RMSF), and the human ehrlichioses.

English-language literature was identified via MEDLINE (1966-January 2002) using the keywords Lyme disease, Rocky Mountain spotted fever, and ehrlichiosis. Textbooks and other pertinent resources were also reviewed.

All articles identified through the data sources above were evaluated and reviewed if pertinent to the objective.

Tick-borne diseases are the most common vector-transmitted diseases in North America. Each disease causes significant morbidity and, in the case of RMSF, mortality if patients go untreated. If the disease syndromes are recognized early and treatment is initiated, complications are greatly reduced. Doxycycline is active against each of the causative organisms, simplifying empiric treatment.

Effective pharmacotherapy exists to treat each of these diseases, assuming diagnosis is made quickly. The beta-lactam and tetracycline antibiotics appear to be the most effective therapy for Lyme disease. The tetracyclines, but not the beta-lactams, are effective for RMSF and the human ehrlichioses. Since Borrelia burgdorferi and the human granulocytic ehrlichiosis agent are becoming more common coinfecting pathogens, tetracycline or doxycycline should be considered the drugs of choice for patients from endemic areas where exposure to both pathogens may have occurred. Doxycycline is the preferred agent because of decreased frequency of administration and adverse effects.