Clinical Validation of Therapeutic Drug Monitoring of Imipenem in Spent Effluent in Critically Ill Patients Receiving Continuous Renal Replacement Therapy: A Pilot Study.
OBJECTIVE
The primary objective of this pilot study was to investigate whether the therapeutic drug monitoring of imipenem could be performed with spent effluent instead of blood sampling collected from critically ill patients under continuous renal replacement therapy.


METHODS
A prospective open-label study was conducted in a real clinical setting. Both blood and effluent samples were collected pairwise before imipenem administration and 0.5, 1, 1.5, 2, 3, 4, 6, and 8 h after imipenem administration. Plasma and effluent imipenem concentrations were determined by reversed-phase high-performance liquid chromatography with ultraviolet detection. Pharmacokinetic and pharmacodynamic parameters of blood and effluent samples were calculated.


RESULTS
Eighty-three paired plasma and effluent samples were obtained from 10 patients. The Pearson correlation coefficient of the imipenem concentrations in plasma and effluent was 0.950 (P<0.0001). The average plasma-to-effluent imipenem concentration ratio was 1.044 (95% confidence interval, 0.975 to 1.114) with Bland-Altman analysis. No statistically significant difference was found in the pharmacokinetic and pharmacodynamic parameters tested in paired plasma and effluent samples with Wilcoxon test.


CONCLUSIONS
Spent effluent of continuous renal replacement therapy could be used for therapeutic drug monitoring of imipenem instead of blood sampling in critically ill patients.
Department of Pharmacy, Beijing Friendship Hospital, Capital Medical University, Beijing, China.
Aiping
A
Wen
School of Chemical Biology and Pharmaceutical Sciences, Capital Medical University, Beijing, China.
Zhe
Z
Li
Department of Pharmacy, Beijing Friendship Hospital, Capital Medical University, Beijing, China.
Junxian
J
Yu
Department of Pharmacy, Beijing Friendship Hospital, Capital Medical University, Beijing, China.
Ren
R
Li
Department of Pharmacy, Beijing Friendship Hospital, Capital Medical University, Beijing, China.
Sheng
S
Cheng
Department of Critical Care Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing, China.
Meili
M
Duan
Department of Critical Care Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing, China.
Jing
J
Bai
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000097:blood*; D016638:Critical Illness / Q000628:therapy*; D016903:Drug Monitoring / Q000379:methods; D005260:Female; D006801:Humans; D015378:Imipenem / Q000008:administration & dosage* / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011446:Prospective Studies; D017582:Renal Replacement Therapy / Q000379:methods
D000900:Anti-Bacterial Agents; D015378:Imipenem