【Background】
Linezolid (LZD) can cause thrombocytopenia associated with high LZD plasma concentrations due to renal dysfunction, etc. This study aimed to clarify whether the rate of achieving LZD concentrations that avoid the toxicodynamic target, that is, the safety target achievement rate, can predict the onset of thrombocytopenia.
【Methods】
Subjects were adult patients hospitalized at Shimane University Hospital, who received LZD treatment. Based on predicted two PK parameters (Parameters A and B) for each patient, the safety target achievement rate (LZD trough concentration of less than 8 μg/mL, at which the risk of thrombocytopenia is low) was calculated. Univariate, multivariate and receiver operating characteristic (ROC) analyses were performed to assess the relationship between patient characteristics including the safety target achievement rate and the onset of thrombocytopenia.
【Results and Discussion】
Patients (n = 77) aged 72 ± 11 years old and weighing 56.7 ± 10.9 kg, with a creatinine clearance of 60.5 ± 47.2 mL/min, were analyzed. A multivariate analysis of several factors stratified with the cutoff values obtained by ROC analysis revealed that the duration of LZD therapy and the safety target achievement rate were significant factors (Parameter A and B: odds ratios for the duration of LZD therapy were 7.436 and 4.712; odds ratios for the safety target achievement rate were 0.060 and 0.167, respectively).
【Conclusion】
The risk of LZD-induced thrombocytopenia, which increased with the duration of LZD therapy, may be predicted using the safety target achievement rate.
