Postoperative Pharmacokinetics of Methadone in Patients With Chronic Kidney Disease
The goal of this observational study is to describe the influence of renal function on the pharmacokinetics of methadone used through an intravenous patient-controlled analgesia (IV-PCA) pump for the management of acute postoperative pain. After surgery the participants will use an IV-PCA of methadone and blood samples will be withdrawn to measure the plasmatic levels of it. The main question the study aims to answer is: • Is the pharmacokinetic of methadone used in an IV-PCA pump impaired in patients with chronic kidney disease?
• Patients with chronic kidney disease (CrCl 15-60 ml/min)
• Patients over 18 years old undergoing surgery requiring general anesthesia with subsequent use of intravenous methadone patient-controlled analgesia
• Hospital stay ≥ 48 hours
• Body mass index 18-35 kg/m2