Pharmacokinetics and Pharmacodynamics of Intravenous Paracetamol in Morbidly Obese and Non- Obese Patients.
Trial Parameters
Brief Summary
Obese patients may need higher doses of acetaminophen (APAP) for adequate analgesia, due to increased total clearance and distribution volume. APAP-induced hepatotoxicity is mainly caused through CYP2E1 pathway. Its activity is induced by obesity, potentially endangering the safety profile of APAP. Metabolic-dysfunction associated liver disease (MASLD) is an important associated risk factor for APAP induced-hepatotoxicity. The primary endpoint of this study is to validate Van Rongen's prediction model on plasma concentration of paracetamol and its metabolites and extend it to the steady state phase over a period of 30 hours by measuring plasma concentrations of paracetamol and its metabolites and comparing them with the plasma concentrations predicted by the model by Van Rongen et al. In addition, results obtained from venous blood will be compared with results obtained via VAMS after finger stick. If VAMS correlates well with plasma concentrations of paracetamol and its NAPQI adducts, future interventional studies may utilize the patient-friendly VAMS technology in an effort to further investigate the safety and efficacy of higher doses of paracetamol in obese patients and possibly other patient groups. The secondary endpoints of this study are liver function tests before and after 30hrs of paracetamol administration, the VAS pain scores, the surgical pleth index (SPI) and the consumption of piritramide as recorded by a PCIA pump.
Eligibility Criteria
Inclusion Criteria: 1. Adult ≥ 18 \< 70 years old (obese patients) Adult ≥ 18 years old (non-obese patients) 2. Able to comprehend, sign, and date the written informed consent document to participate in the clinical trial 3. Obese scheduled for laparoscopic bariatric surgery Non obese scheduled for laparoscopic surgery 4. Control group BMI ≥18.5 en \<30 kg.m-2 or Obese group BMI \> 35kg.m-2 5. ASA Class I, II or III as assigned by the anaesthesiologist Exclusion Criteria: 1. Allergy or inability to tolerate "paracetamol" 2. Documented Liver disease or liver enzymes \> 3X normal value 3. Kidney disease (eGFR \< 30ml.min-1) 4. Participation in a clinical trial within the past 30 days 5. Chronic alcohol abuse or alcohol intake \<72hrs 6. Gilbert-Meulengracht-syndroom 7. Chronic malnutrition 8. Intake of medication with influence on CYP2E1 or UDP-glucuronosyltransferase 9. Pregnancy