Analysis of the Influence of Gastric By-Pass on the Pharmacokinetics of Common Drugs

Inclusion Criteria: * Age ≥ 18 years * Patients having undergone a complete bariatric course, eligible for bariatric surgery after validation of the operative indication by a multidisciplinary RCP dedicated to obesity, in accordance with HAS criteria: morbid obesity with BMI \> 40 kg/m2 or severe obesity with BMI \>35Kg/m2 * Patients with a comorbidity linked to one of the elements of metabolic syndrome that can be improved by surgery: type 2 diabetes, hypertension, dyslipidemia. * Patients treated pre-operatively for at least 2 weeks with one or more of the molecules designed to control metabolic syndrome and selected for our study: * Antihypertensive: amlodipine; candesartan, * Hypolipidemic: rosuvastatin * Hypoglycemic agent: metformin * Patients scheduled for Y-shaped gastric bypass surgery * Membership of a social security scheme Exclusion Criteria: * History of restrictive bariatric surgery (sleeve) * History of renal or hepatocellular insufficiency * Patient undergoing treatment or having stopped treatment within the last month with a drug that may alter the clearance of the molecules studied: enzyme inducer or inhibitor (boosted antiproteases, macrolides, azole antifungals, grapefruit juice, rifampicin, rifabutin, phenobarbital, phenytoin, St John's wort), probenecid, non-steroidal anti-inflammatory drugs, etc. * Patients treated with a drug that may alter the bioavailability of associated drugs: antacids containing aluminium or magnesium hydroxide, gastric dressings, etc. * Patients for whom it is impossible to give informed consent (language barrier) * Patients taking part in another interventional clinical study * Patients under legal protection (guardianship, curatorship) * Pregnant or breast-feeding women