Overview

This randomized, double-blind controlled trial investigates whether intraoperative intravenous methadone (0.15 mg/kg based on ideal body weight) reduces acute postoperative pain and opioid consumption in patients undergoing elective total hip arthroplasty under spinal anesthesia with mepivacaine. The primary outcome is patient-reported pain on a visual analog scale (VAS) 30-60 minutes after arrival in the post-anesthesia care unit (PACU). Secondary outcomes include opioid use, pain scores over time, incidence of nausea/vomiting, and quality of recovery. A total of 162 subjects will be enrolled at MUSC surgical sites.

Eligibility

Inclusion

• Ages 18-75 years of age
• Undergoing elective primary total hip arthroplasty with mepivacaine in the spinal anesthesia

Exclusion

• Allergy to methadone or mepivacaine
• Severe liver disease defined as Child's Pugh Class C
• End stage renal disease requiring dialysis
• Known diagnosis of prolonged QT syndrome
• Currently pregnant
• Unable to provide written, informed consent
• Non-English speaking