title: Influence of bariatric surgery on the use of medication.
abstract: OBJECTIVE
  Bariatric surgery can influence the prevalence and incidence of comorbidities, as well as the pharmacokinetics of drugs. This might lead to changes in the use of drugs. This study aimed to assess the influence of bariatric surgery on the use of medication in patients before and after surgery, focusing on type, number of medications, and daily dosage.
  
  
  METHODS
  In a retrospective and prospective observational study, drug dispensing data from pharmacies of patients undergoing their first bariatric surgery between January 2008 and September 2011 was collected. Dispensing data from 1 month before until 12 months after surgery was analyzed. Drugs were classified according to the WHO-ATC classification system. Dosages of drugs were compared using defined daily dose (DDD).
  
  
  RESULTS
  Among 450 patients, 12 months after surgery, the mean number of drugs per patient for antidiabetics, drugs acting on the cardiovascular system, anti-inflammatory and antirheumatic drugs, and drugs for obstructed airway diseases decreased by, respectively, 71.3 % (95 % CI 57.2 to 85.4), 34.5 % (95 % CI 28.2 to 43.0), 45.5 % (95 % CI 13.3 to 72.6), and 33.1 % (95 % CI 15.3 to 53.2). Patients used lower median DDD of oral antidiabetics, beta-blocking agents, and lipid-modifying drugs.
  
  
  CONCLUSIONS
  For some major drug classes 12 months after bariatric surgery, the use of drugs decreases in terms of mean number per patient. A reduction in dose intensity was observed for oral antidiabetics, beta-blocking agents, and lipid-modifying drugs. Dispensing data from pharmacies may provide detailed information on the use of medications by patients after bariatric surgery.
authors.affiliation: Department of Clinical Pharmacy and Clinical Pharmacology, Medical Centre Leeuwarden, PO Box 888, 8901 BR, Leeuwarden, The Netherlands. j.p.yska@znb.nl.
authors.forename: Jan Peter
authors.initials: JP
authors.lastname: Yska
authors.affiliation: Department of Clinical Pharmacy and Clinical Pharmacology, Medical Centre Leeuwarden, PO Box 888, 8901 BR, Leeuwarden, The Netherlands.
authors.forename: Douwe H
authors.initials: DH
authors.lastname: van der Meer
authors.affiliation: Department of Clinical Pharmacy and Clinical Pharmacology, Medical Centre Leeuwarden, PO Box 888, 8901 BR, Leeuwarden, The Netherlands.
authors.forename: Albert R
authors.initials: AR
authors.lastname: Dreijer
authors.affiliation: Department of Clinical Pharmacy and Clinical Pharmacology, Medical Centre Leeuwarden, PO Box 888, 8901 BR, Leeuwarden, The Netherlands.
authors.forename: Willeke
authors.initials: W
authors.lastname: Eilander
authors.affiliation: Department of Surgery, Medical Centre Leeuwarden, Leeuwarden, The Netherlands.
authors.forename: Jan A
authors.initials: JA
authors.lastname: Apers
authors.affiliation: Department of Surgery, Medical Centre Leeuwarden, Leeuwarden, The Netherlands.
authors.forename: Marloes
authors.initials: M
authors.lastname: Emous
authors.affiliation: Department of Surgery, Medical Centre Leeuwarden, Leeuwarden, The Netherlands.
authors.forename: Erik R E
authors.initials: ER
authors.lastname: Totté
authors.affiliation: Unit of Pharmacotherapy and Pharmaceutical Care, Department of Pharmacy, University of Groningen, Groningen, The Netherlands.|Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Bob
authors.initials: B
authors.lastname: Wilffert
authors.affiliation: Department of Clinical Pharmacy and Clinical Pharmacology, Medical Centre Leeuwarden, PO Box 888, 8901 BR, Leeuwarden, The Netherlands.|Unit of Pharmacotherapy and Pharmaceutical Care, Department of Pharmacy, University of Groningen, Groningen, The Netherlands.
authors.forename: Eric N
authors.initials: EN
authors.lastname: van Roon
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000328:Adult; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D018501:Antirheumatic Agents / Q000627:therapeutic use; D050110:Bariatric Surgery; D002317:Cardiovascular Agents / Q000627:therapeutic use; D004363:Drug Utilization / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D057847:Lipid Regulating Agents / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D010594:Pharmacies / Q000706:statistics & numerical data*
chemical_list: D000319:Adrenergic beta-Antagonists; D000893:Anti-Inflammatory Agents; D018501:Antirheumatic Agents; D002317:Cardiovascular Agents; D007004:Hypoglycemic Agents; D057847:Lipid Regulating Agents
keywords: Bariatric surgery; Defined daily dose; Dispensing data; Medication use