Neomycin sulfate is a broad spectrum aminoglycoside antibiotic composed of a number of related neomycin compounds including neomycin A (neamine), neomycin B (framycetin), neomycin C, and a few minor compounds found in much lower quantities. Neomycin B is the most active component in neomycin followed by neomycin C and neomycin A. This product acts by binding to the 30S and 50S subunits, causing miscoding and inhibiting initiation and elongation during protein synthesis. Neomycin also blocks voltage-sensitive Ca²⁺+ channels without affecting the Na⁺/Ca²⁺ antiporter in neurons.
