Bacitracin is primarily used as a topical preparation, as it can cause kidney damage when used internally.[3] It is generally safe when used topically, but in rare cases may cause
hypersensitivity,
allergic or
anaphylactic reactions, especially in people allergic to
neomycin.[4][5]
In 2021, it was the 300th most commonly prescribed medication in the United States, with more than 400,000 prescriptions.[6][7]
As bacitracin zinc salt, in combination with other topical antibiotics (usually
polymyxin B and
neomycin) as an
ointment ("triple antibiotic ointment," with the brand name
Neosporin), it is used for topical treatment of a variety of localized skin and eye infections, as well as for the prevention of wound
infections. A non-ointment form of ophthalmic solution is also available for eye infections.[9]
Spectrum of activity and susceptibility data
Bacitracin is a narrow-spectrum antibiotic. It targets Gram-positive bacteria, especially those that cause skin infections. The following represents susceptibility data for a few medically significant microorganisms.[10]
Bacitracin interferes with the dephosphorylation of
C55-isoprenyl pyrophosphate, and a related molecule known as
bactoprenol pyrophosphate; both of these lipids function as membrane carrier molecules that transport the building-blocks of the
peptidoglycan bacterial
cell wall outside of the inner membrane.[11]
One strain isolated from tissue debrided from a compound fracture of the tibia was particularly active. We named this growth-antagonistic strain for the patient, "Tracy I." When cell-free filtrates of broth cultures of this bacillus proved to possess strong antibiotic activity and to be non-toxic, further study seemed warranted. We have called this active principle "Bacitracin.[12]
Bacitracin was approved by the US FDA in 1948.[15]
Bacitracin is composed of a mixture of related compounds with varying degrees of antibacterial activity. Notable fractions include bacitracin A, A1, B, B1, B2, C, D, E, F, G, and X.[17] Bacitracin A has been found to have the most antibacterial activity. Bacitracin B1 and B2 have similar potencies and are approximately 90% as active as bacitracin A.[18]
^Elks J, Ganellin CR (1990). The Dictionary of Drugs: Chemical Data: Chemical Data, Structures and Bibliographies. Springer. pp. 119–.
ISBN978-1-4757-2085-3.
^Zintel HA, Ma RA (October 1949). "The absorption, distribution, excretion and toxicity of bacitracin in man". The American Journal of the Medical Sciences. 218 (4): 439–445.
doi:
10.1097/00000441-194910000-00012.
PMID18140540.
S2CID2371497.
^"Committee for Veterinary Medicinal Products Bacitracin." Ema.europa.eu. The European Agency for the Evaluation of Medicinal Products, June 1998. Web. 18 January 2013