Tigecycline for Severe Rickettsioses: Gained Experience Needing a Slight Grain of Salt.

Abstract

We read with interest the article by Mastroianni and colleagues titled “Does Tigecycline Have a Place in Therapy for Rickettsial Infection of the Central Nervous System [1].” In this report, the authors describe their experience using tigecycline to treat those with neurologic manifestations of spotted fever group (SFG) rickettsiosis in Italy. In their series of 5 patients, they report a favorable response to the use of high dose tigecycline (200 mg loading dose followed by 100 mg administered twice daily). Tigecycline, a relatively unproven antibiotic for clinical rickettsioses, has in vitro activity against several tested rickettsiae [2, 3] and appears effective in an animal model for lethal Rocky Mountain spotted fever (RMSF) [3]. Although doxycycline is the agent of choice, manifestations such as nausea/vomiting or concern for impaired absorption associated with critical illness, may preclude its oral use. Unfortunately, as highlighted by this article, the parenteral formulation is not always available in some regions [1, 3]. Sharing clinical therapeutic experience through publication of observational studies is of importance when controlled trials are not feasible, so the case series by Mastroianni et al. [1] may be very helpful to clinicians faced with severe manifestations of SFG rickettsioses without the availability of intravenous doxycycline.