a form of penicillin resistant to penicillinase and effective against penicillin-resistant staphylococci
A narrow-spectrum beta-lactam antibiotic made by chemical modification of penicillin and administered in the form of its hydrated sodium salt C₁₉H₁₈N₃NaO₅S·H₂O to treat infections caused by penicillin-resistant staphylococci.