Methadone Pharmacokinetics in End-stage Renal Disease
Trial Parameters
Brief Summary
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 After surgery the participants will use an IV-PCA of methadone and blood samples will be withdrawn to measure the plasmatic levels of it.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?
Eligibility Criteria
Inclusion Criteria: * 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 Exclusion Criteria: * History of liver disease * Need for dialysis (hemo or peritoneal dialysis) * Use of home oxygen therapy * American Society of Anesthesiologists (ASA) physical status IV-V * Pregnancy * Chronic opioid use * Methadone allergy * Prolonged QT interval * Use of antiarrhythmics that prolong the QT interval * Inability to understand the proper use of PCA