Common Errors Related to Vancomycin Pharmacokinetics, Prescribed by Physicians in Iran: Suggesting Practical Approaches for Adjusting the Right Dose

Background: Vancomycin is a glycopeptide antibiotic that is widely used for the treatment of gram-positive microorganisms, including methicillin-resistant Staphylococcus aureus. It is a valuable antibiotic in practice; unfortunately, its excessive use and mistakes in prescription have increased bacterial resistance. Hence, this study seeks to investigate the common errors related to the pharmacokinetics of vancomycin prescription in teaching hospitals in Iran. Methods: This study is an observational study that research orders with errors related to pharmacokinetics parameters of vancomycin. A total of 150 patients were enrolled in the study from May 2016 to September 2018 in teaching hospitals. Errors in drug prescription were identified based on literature resources. Results: About 22.7% of patients did not receive the loading dose. Also, 85.3% of patients were prescribed a fixed dose, instead of weight-based dosing. About 46% of patients had kidney problems (chronic kidney disease or acute kidney injury) and all of them had received a much lower dose than they needed according to guidelines. Another 46% of patients did not undergo therapeutic dose monitoring correctly. Finally, 69.3% of patients had not received consequent doses after encountering a nontherapeutic trough level correctly. Also, none of 22 obese patients with a body mass index of greater than 40 kg/m2, had received the proper dose. Conclusion: Since the incorrect use of vancomycin significantly increases the prevalence of resistant organisms and, consequently, the mortality rate of patients, it is necessary to define guidelines for its use in the hospital.