Vancomycin is primarily used as an antibiotic to treat serious bacterial infections caused by Gram-positive bacteria, particularly those that are resistant to other antibiotics. It is often administered intravenously for conditions such as complicated skin infections, bloodstream infections, endocarditis, bone and joint infections, and meningitis. In cases where patients have severe allergies to penicillin or cephalosporins, vancomycin serves as a critical alternative. It is also used prophylactically to prevent infections during certain surgical procedures, especially in patients at high risk for methicillin-resistant Staphylococcus aureus (MRSA) infections. Additionally, vancomycin is effective in treating Clostridioides difficile-associated diarrhea when taken orally, as it acts locally in the gastrointestinal tract without significant systemic absorption. Its use is carefully monitored due to potential side effects, such as kidney toxicity and hearing loss, and to ensure optimal dosing for therapeutic efficacy.