Penicillin V (0.063-0.25 mg/kg; s.c.) inhibits the outgrowth of S. aureus in mice thigh muscle. Penicillin V (2 mg/kg; s.c.) exhibits the plasma half-life (61 min) and mean AUC (0.47 mg/L·h). Penicillin V (100 mg/kg; p.o. once daily for 5 d) avoids the fulminant infection of acute purulent otitis media (AOM) in rats.