Serum concentration as a predictor of tigecycline-induced hypofibrinogenemia in critically ill patients: A retrospective cohort study.

• Tigecycline treatment causes a significant decrease in fibrinogen levels. • Tigecycline exposure is highly predictive of hypofibrinogenemia. • Serum concentration at the 6 hours after the dosing (C 1/2) ≥ 0.645 mg/l with best predictive performance may be the optimal toxicity threshold. This study aimed to determine the thresholds of serum concentration as a predictor of tigecycline (TGC)-induced hypofibrinogenemia (HF) in critically ill patients. A retrospective cohort study was conducted in intensive care unit patients treated with TGC. The clinical data and serum concentration were extracted from the patients' electronic medical records. Patients were divided into an HF group and a normal group according to fibrinogen value. The receiver operating characteristic curves and logistic regression were used to derive serum concentration thresholds and quantify the association between exposure thresholds and HF while adjusting for confounders. In total, 100 patients were included. The receiver operating characteristic curves analysis showed that TGC concentration parameters were strongly predictive of HF. Adjusting for duration of TGC, serum concentration at the 6 hours after the dosing (C 1/2) ≥ 0.645 mg/l, area under the concentration-time curve over a 24-hour period (AUC 0-24) ≥ 20.76 mg·h/l, and serum concentration of 30 minutes before next dose (C min) ≥ 0.455 mg/l were associated with a three- to five-fold increased risk of TGC-induced HF in logistic regression. The findings from this study provide evidence that TGC exposure is highly predictive of HF, with an approximately three- to five-fold increased risk. Serum concentration at the 6 hours after the dosing (C 1/2) ≥ 0.645 mg/l with best area under the receiver operating characteristic curve and negative predictive value appears to be the most appropriate toxicity threshold. [Display omitted] [ABSTRACT FROM AUTHOR]