Bacitracin characteristics include which of the following?

• A. Oral systemic antibiotic
• B. Broad-spectrum systemic
• C. Polypeptide bactoprenol inhibitor
• D. Topical only - toxic

Answer: (D)

Bacitracin’s key clinical trait is that it is used only topically because it can cause severe toxicity if given systemically. It is a polypeptide antibiotic that inhibits cell wall synthesis by interfering with bactoprenol cycling, but this mechanism alone doesn’t define how it’s used. In practice, its systemic toxicity (notably nephrotoxicity) limits it to topical applications like on the skin or in the eye. That makes the statement “topical only – toxic” the best overall description of its characteristics. The other statements describe uses or spectra that don’t fit its real clinical use.