Methadone Pharmacokinetics in Cardiac Surgery

Exclusion Criteria

• •Severe liver or kidney dysfunction (Child-Pugh class B/C, eGFR \<30 mL/min/1.73m², creatinine \>2 mg/dL, dialysis)
• •Allergy to methadone or fentanyl
• •Use of CYP3A4 inducers (rifampin, phenytoin, carbamazepine), CYP3A4 inhibitors (ketoconazole, erythromycin, clarithromycin, itraconazole), SSRIs (fluoxetine, sertraline, paroxetine, citalopram, escitalopram, fluvoxamine)
• •Body mass index \>40 kg/m²
• •Corrected QT interval interval \>500 milliseconds
• •Intubation anticipated \>12 hours
• •History of illicit drug use or alcohol or opioid abuse use disorder within last 12 months
• •Mechanical circulatory support, heart transplant, deep hypothermic circulatory arrest procedures
• •Left Ventricular Ejection Fraction \<30%
• •Pulmonary disease requiring oxygen therapy
• •Preoperative inotropic support or intra-aortic balloon pump
• •Emergency surgery
• •Postoperative regional anesthesia
• •Hemofiltration during cardiopulmonary bypass