Pfizerpen Injection (Penicillin G Potassium) 5,000,000 Units per Vial, Hospira Pfizer 10/Pack (RX)Pfizerpen Injection (Penicillin G Potassium) is an antibiotic used to treat a wide range of bacterial infections. It is particularly effective against severe infections such as bacterial endocarditis, meningitis, pneumonia, septicemia, and syphilis. Penicillin G works by inhibiting the synthesis of bacterial cell walls, ultimately leading to the destruction of the bacteria. Administered intravenously or intramuscularly, it is crucial for patients to