Phenoxymethylpenicillin is a penicillin antibiotic that is orally active. It is less active than benzylpenicillin against Gram-negative bacteria. Phenoxymethylpenicillin is more acid-stable than benzylpenicillin, which allows it to be given orally. It exerts a bactericidal action against penicillin-sensitive microorganisms during the stage of active multiplication. It acts by inhibiting the biosynthesis of cell-wall peptidoglycan. It is not active against beta-lactamase-producing bacteria, which include many strains of Staphylococci. Phenoxymethylpenicillin has a range of antimicrobial activity against Gram-positive bacteria that is similar to that of benzylpenicillin and a similar mode of action, but it is substantially less active than benzylpenicillin against Gram-negative bacteria. Phenoxymethylpenicillin is usually used only for the treatment of mild to moderate infections, and not for severe or deep-seated infections since absorption can be unpredictable.