Vancomycin is an antibiotic used to treat serious bacterial infections, particularly those caused by Staphylococcus aureus and Streptococcus species. It works by inhibiting the synthesis of bacterial cell walls, which ultimately leads to the death of the bacteria. Vancomycin is often prescribed for patients who are allergic to penicillin or when bacteria are resistant to other antibiotics. This medication is typically administered intravenously for severe infections, although it can also be given orally for specific conditions like Clostridium difficile infections. Monitoring is essential during treatment, as vancomycin can cause side effects, including kidney damage and hearing loss if not used properly.