Rocky mountain spotted fever is a potentially fatal infectious disease wich is transmitted trough vectors. This particular infection is caused by Rickettsia rickettsii wich is a gramnegative intracellular bacilli. The pathophysiological mechanism and clinical manifestation is mainly due to the vascular affectation, since this pathogen has a tropism for endothelial cells. As it has been mentioned, this is an obligate intracellular pathogen, so the main choice with the antibiotic therapy is tetracyclines because of its action mechanism in the inhibition of the subunit 30S. The objective of the study is to prove new strategies of treatment to improve the pharmacological aproach by implementing Azithromycin, wich is a macrolide that inhibits de 50S subunit of the bacteria. Azithromycin has shown effectivity against other rickettsial diseases.