Triple/BNP ocular antibiotic combination contains which components?

• A. Bacitracin + Neomycin + Polymyxin B
• B. Terramycin
• C. Cefazolin
• D. Erythromycin

Answer: (A)

The main idea here is recognizing what the BNP triple antibiotic ointment is composed of. BNP stands for a three-drug combination: bacitracin, neomycin, and polymyxin B. Each component brings a different spectrum of activity, and together they provide broad coverage for many bacteria that affect the ocular surface. Bacitracin mainly targets Gram-positive organisms by inhibiting cell wall synthesis. Neomycin is an aminoglycoside with good activity against many Gram-negative bacteria (and some Gram-positives). Polymyxin B is particularly strong against Gram-negative bacteria by disrupting the outer membrane. Using them together gives us a topical option that covers a wide range of potential culprits in equine eye infections, often used empirically before culture results are known.

The other listed agents are distinct antibiotics not part of this specific combination. Terramycin refers to oxytetracycline, which is a separate antibiotic with its own spectrum. Cefazolin is a first-generation cephalosporin, and erythromycin is a macrolide; neither forms the BNP trio.