Babesiosis Medication

Updated: Apr 01, 2021
  • Author: Rachel E Strength, MD; Chief Editor: Michael Stuart Bronze, MD  more...
  • Print

Medication Summary

The goals of pharmacotherapy are to reduce morbidity, to prevent complications, and to eradicate the infection. A combination of an antiprotozoal agent and an antibiotic—atovaquone plus azithromycin or, alternatively, quinine plus clindamycin—is used to treat symptomatic patients in order to prevent sequelae and potential transmission through blood donation. Other regimens have been reported in isolated case reports.


Antiprotozoal Agents

Class Summary

Protozoal infections occur throughout the world and are a major cause of morbidity and mortality in some regions. Cinchona alkaloids (eg, quinine) are effective in eradicating the parasite.

Quinine (Qualaquin)

Quinine is a schizonticide. It inhibits the growth of the parasite by increasing the pH within intracellular organelles and possibly by intercalating itself into the DNA of the parasite. It is used in combination with clindamycin.

Antiprotozoal Agents

Atovaquone is a hydroxynaphthoquinone that inhibits the mitochondrial electron transport chain by competing with ubiquinone at the ubiquinone-cytochrome-c-reductase region (complex III). Inhibition of electron transport by atovaquone results in inhibition of nucleic acid and adenosine triphosphate (ATP) synthesis in the parasites. This agent is used in combination with azithromycin.


Antibiotics, Other

Class Summary

Empiric antimicrobial therapy must be comprehensive and should cover all likely pathogens in the context of the clinical setting.

Clindamycin (Cleocin)

Clindamycin inhibits bacterial growth, possibly by blocking dissociation of peptidyl transfer RNA (tRNA) from ribosomes, causing RNA-dependent protein synthesis to arrest. It is administered in combination with quinine.

Azithromycin (Zithromax, Zmax)

Azithromycin is one of the newer macrolide antibiotics. It inhibits bacterial growth, possibly by blocking dissociation of peptidyl tRNA from ribosomes, causing RNA-dependent protein synthesis to arrest. Plasma concentrations of azithromycin are very low, but tissue concentrations are much higher, making this agent valuable in the treatment of infections caused by intracellular organisms. Azithromycin has a long tissue half-life. It is administered in combination with atovaquone to treat mild-to-moderate microbial infections.

Doxycycline (Vibramycin, Doryx, Monodox)

The combination of clindamycin, doxycycline, and azithromycin was successfully used in a patient who was allergic to quinine. This agent is a bacteriostatic drug that interferes with bacterial protein and cell-wall synthesis during active multiplication by binding to the 30S ribosome. For severe cases, administer intravenously (IV); for outpatients, oral administration (PO) is preferred.