Background: Vancomycin was first approved by the US Food and Drug Administration (FDA) in 1958. Vancomycin has an active effect on gram-positive microorganisms, such as methicillin- resistant Staphylococcus aureus (MRSA), coagulase-negative staphylococcus, Streptococcus (Enterococcus faecalis), and Clostridia (Clostridium difficile). It is used in the treatment of severe infections such as endocarditis, osteomyelitis, pneumonia, blood and soft tissue infections, other staphylococcal infections, and S. epidermidis with a β-lactam ring structure that is ineffective or allergic to antibiotics and resistant to many drugs. Materials and Methods: To carry out the study, we obtained permission to conduct the study from the National Institute of Health and Welfare, and randomly sampled a total of 274 inpatients who used vancomycin in the hospital in 2023 in order to be representative in terms of age and gender (n=120). Results The one dose of vancomycin was 0.9 mg, the daily dose was 2.4 mg, the total dose was 20.5 mg, and the total daily average was 11.3 days. The daily dose and total dose of vancomycin were inversely proportional to age (r=-0.008), and the total dose is very weakly correlated with BMI and gender (r=0.052). Cefazolin used in combination with vancomycin had statistically significant differences in monocyte counts (p=0.003), cefotaxime in lymphocyte counts (p=0.027), and ceftriaxone in total white blood cell counts (p=0.048). Conclusion: Vancomycin daily dose is inversely related to age, total dose is inversely related to age, and total dose is very weakly correlated with BMI and gender. There is a statistically significant difference in the use of vancomycin with cephalosporin antibiotics

: A study by Marsot and other investigators (2012) determined that the dose of vancomycin in adults is directly dependent on parameters such as creatinine clearance and body weight, as well as the need for dose correction. We used the MDRD equation to determine renal dysfunction in 113 inpatients and found grade I in 50.5%, grade II in 14.4%, grade III in 10.8%, grade IV in 6.3%, and grade V in 18%. There is a statistically significant difference (p=0.045) in renal dysfunction depending on the diagnosis. The average daily dose of vancomycin was 2.5 g, the total daily dose was 8.5 g, the total dose was 20.5 g. The daily dose and total dose of vancomycin were inversely proportional to age (g = -0.256), the daily dose was directly related to excess weight body (g=0.226), and days of vancomycin use are statistically significant (p=0.001) depending on the diagnosis. Conclusion Comprehensive programs are required to improve the vancomycin use in the hospitals. Vancomycin use should be monitored due to its large-scale empiric use. The rate of improper use of vancomycin in the infection and intensive care unit services may be high, and pharmacists must take appropriate action to optimize the use of the drug.