Generic vancomycin products: Analysis of serum concentrations in patients with acute myeloid leukemia

Concerns have recently emerged about the quality of generic vancomycin products. Our aim is to analyze serum vancomycin concentrations measured 48 hours after the start of an empirical treatment regimen in patients with acute myeloid leukemia (AML) who received one of the two generic vancomycin products available in France.

Seventy-nine AML patients treated with vancomycin during two study periods were included in the study. Our vancomycin dosing regimen was based on the patients' total body weight adjusted for renal clearance.

A total of 93 serum vancomycin concentrations were collected: 31 in period 1 and 62 in period 2. In bivariate analysis, the mean serum vancomycin concentrations were not significantly different (19.9 ± 11.2 mg/L in period 1 vs 18.9 ± 6.0 mg/L in period 2, P=0.64). In the final generalized estimating equations model, serum vancomycin concentrations correlated statistically with a positive coefficient for age (P<0.001) and with negative coefficients for male sex (P=0.001) and hemoglobin level (P=0.021).

Serum vancomycin concentrations measured 48 hours after the start of an empirical treatment were not influenced by the nature of the generic product but correlated with age, sex and hemoglobin level in AML patients.