Teicoplanin A2-4 is primarily used as an antibiotic in the treatment of severe bacterial infections, particularly those caused by Gram-positive bacteria. It is effective against infections such as endocarditis, osteomyelitis, and septicemia, especially when caused by methicillin-resistant Staphylococcus aureus (MRSA) or other resistant strains. Its application is critical in hospital settings for patients who are allergic to penicillin or have infections unresponsive to other antibiotics. Additionally, it is used in surgical prophylaxis to prevent infections during procedures involving high-risk patients. Its long half-life allows for once-daily dosing, making it a convenient option for both inpatient and outpatient treatment.