Pharmacokinetics of Acetaminophen in Morbidly Obese Patients

Pharmacokinetics of Intravenous Acetaminophen and Its Metabolites in Morbidly Obese Patients

This study will investigate the pharmacokinetics of acetaminophen in morbidly obese patients versus normal weight patients. Specifically the different metabolic pathways of acetaminophen in morbidly obese adults will be investigated; glucuronidation, sulphation and CYP2E1 (cytochrome P450 2E1) oxidation

Inclusion criteria for morbidly obese patients:

• BMI > 40 kg/m2 undergoing bariatric surgery.
• Patients between 18 - 60 years old
• ASA physical classification of II or III
• All racial and ethnic groups will be included

Inclusion criteria for control group:

• BMI between 18 and 25 kg/m2 undergoing general surgery
• Patients between 18 - 60 years old
• ASA (American Society of Anesthesiology) physical classification of I, II or III
• All racial and ethnic groups will be included

Exclusion criteria for all study arms:

• Renal insufficiency
• Liver disease
• Patients with Gilbert-Meulengracht syndrome
• Chronic alcohol intake or use of alcohol within last 72 hours
• Pregnancy or breastfeeding
• Patients who are treated with drugs know to affect CYP2E1 and UGT (UDP glucuronosyltransferase)
• Diabetes mellitus type II patients
• Smoking
• Acetaminophen intake before the study (24 hours before study)