Antibiotics Used Topically with Emphasis on Neomycin and Bacitracin

5 Antibiotics Used Topically with Emphasis on Neomycin and Bacitracin 

Neomycin, produced by the bacterium Streptomyces fradiae, is an aminoglycoside antibiotic that shows good activity against gramnegative bacteria and some gram-positives. Neomycin is made up of neomycin B and neomycin C. Hydrolysis of neomysin B yields neamine made up of neosamine B and the amino-cyclitol, 2-deoxystreptamine, and the disaccharide neobiosamine B composed of o-ribose and neosamine B. Hydrolysis of neomycin C produces neamine and neobiosamine C, a disaccharide 

3 Cross-reactions Between Bacitracin and Aminoglycoside Antibiotics 

Immediate allergic reactions including anaphylaxis also occur to other aminoglycoside antibiotics with cases recorded for neomycin, gentamycin, tobramycin, framycetin, streptomycin, and dihydrostreptomycin. In some of these cases where tests were undertaken, patch and/or skin tests proved positive to the culprit aminoglycoside, but cross-reactivity with bacitracin has not been reported or, it seems, looked for. 

Unexpectedly, some patients demonstrate contact allergy to both bacitracin and neomycin 

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