title: The Effect of Roux-en-Y Gastric Bypass Surgery in Morbidly Obese Patients on Pharmacokinetics of (Acetyl)Salicylic Acid and Omeprazole: the ERY-PAO Study.
abstract: Data on the absorption of orally administered drugs following Roux-en-Y gastric bypass (RYGB) surgery in obese patients are limited and inconclusive. As it is difficult to predict changes in absorption, studies on frequently used drugs in this population are necessary. Acetylsalicylic acid (ASA) and omeprazole are two commonly prescribed drugs in obese patients.
  
  
  
  In this repeated measures study, omeprazole and salicylic acid (SA) serum concentrations were measured before and after RYGB in 34 morbidly obese subjects. Time to maximum concentration (Tmax), lag time (Tlag), maximum concentration (Cmax), and area under the serum concentration versus time curve (AUC) were calculated for both drugs to determine possible differences in drug absorption after the procedure.
  
  
  
  For SA, Tmax significantly decreased after RYGB, while both Cmax and AUC0-24 significantly increased. For omeprazole, both Tmax and Tlag significantly decreased after RYGB, while Cmax significantly increased. Mean AUC0-12 significantly decreased post-surgery. The difference in AUC0-12 before and after surgery varied between subjects.
  
  
  
  Our study shows a faster absorption of both ASA and omeprazole after RYGB. The exposure to ASA is higher post-surgery, but the standard dose of 80 mg does not need to be modified, considering its range in effective dose. The exposure to omeprazole is, on average, decreased after surgery. Clinicians should be aware to increase the dose of omeprazole if symptoms suggest inadequate response.
authors.affiliation: Department of Clinical Pharmacy, Ikazia Hospital and Maasstad Hospital, Rotterdam, The Netherlands. l.mitrov@ikazia.nl.
authors.forename: Lieke
authors.identifier: 0000-0003-4133-2370
authors.initials: L
authors.lastname: Mitrov-Winkelmolen
authors.affiliation: Department of clinical pharmacy, BovenIJ Hospital, Amsterdam, The Netherlands.
authors.forename: Marie-Christine W
authors.initials: MW
authors.lastname: van Buul-Gast
authors.affiliation: Dutch Obesity Clinic West, The Hague, The Netherlands.
authors.forename: Dingeman J
authors.initials: DJ
authors.lastname: Swank
authors.affiliation: Central Hospital Pharmacy, Medical Centre The Hague, The Hague, The Netherlands.
authors.forename: Hans W P M
authors.initials: HWPM
authors.lastname: Overdiek
authors.affiliation: Department of Clinical Chemistry, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: Ron H N
authors.initials: RHN
authors.lastname: van Schaik
authors.affiliation: Department of Clinical Pharmacy and Pharmacology, University Medical Centre Groningen Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Daan J
authors.initials: DJ
authors.lastname: Touw
mesh_terms: D000284:Administration, Oral; D000897:Anti-Ulcer Agents / Q000493:pharmacokinetics*; D019540:Area Under Curve; D001241:Aspirin / Q000493:pharmacokinetics*; D005260:Female; D015390:Gastric Bypass / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000378:metabolism / Q000601:surgery*; D009853:Omeprazole / Q000493:pharmacokinetics*; D010975:Platelet Aggregation Inhibitors / Q000493:pharmacokinetics*
chemical_list: D000897:Anti-Ulcer Agents; D010975:Platelet Aggregation Inhibitors; D009853:Omeprazole; D001241:Aspirin
keywords: Acetylsalicylic acid (Aspirin); Drug absorption; Omeprazole; Roux-en-Y gastric bypass