Frequency of decreased renal function between patients treated with brand and generic products of vancomycin hydrochloride injection

The frequency of decreased renal function was compared between patients treated with brand and generic products of vancomycin injection (VCM) in a retrospective manner based on the clinical examination records archived in Okayama University Hospital. A total of 122 patients were found to have been solely treated with vancomycin injection for MRSA infection, and their examination records were analyzed. The renal function of those patients was evaluated based on the serum creatinine concentration (SCr), and patients whose SCr was maximally elevated above the defined upper limit of the normal range (1.20 mg/dl for males and 0.96 mg/dl for females) were considered to show decreased renal function. Although the amount of VCM administered to patients was larger in the case of generic rather than brand products, the percentage of patients whose renal function was decreased during VCM treatment was not significantly different between the VCM products, in which 2 among 62 patients receiving the brand product and 4 among 60 receiving the generic product were reported to show decreased renal function. It was additionally revealed that 3 of those 4 patients with a decreased renal function related to the generic product were not treated as instructed by the package insert, and their trough VCM concentration exceeded the recommended level of 10 μg/ml. With these findings, the brand and generic VCM products are considered to be similar regarding the adverse effect of decreasing renal function.