Which combination is an aminoglycoside + cationic polypeptide + dexamethasone used post-operatively?

• A. Neomycin/Polymyxin/Dexamethasone
• B. Tobramycin/Polymyxin/Dexamethasone
• C. Gentamicin/Polymyxin/Dexamethasone
• D. Neomycin/Dexamethasone

Answer: (A)

Postoperative eye drops often combine an antibiotic with a steroid to prevent infection and control inflammation after surgery. The described trio is an aminoglycoside plus a cationic polypeptide plus dexamethasone. Neomycin provides broad antimicrobial activity as the aminoglycoside; polymyxin B is the cationic polypeptide that disrupts bacterial outer membranes, especially Gram-negative organisms; and dexamethasone reduces inflammation and helps prevent postoperative edema and irritation. This specific three-drug combo is a well-established postoperative regimen for cataract surgery, offering both infection prevention and inflammation control in one drop.

The other options don’t meet the exact three-part combination: they either replace the polymyxin B with a different antibiotic or omit the steroid, so they don’t fit the described aminoglycoside + cationic polypeptide + dexamethasone formulation.