title: Effect of azithromycin on acid reflux, hiatus hernia and proximal acid pocket in the postprandial period.
abstract: BACKGROUND
  The risk for acidic reflux is mainly determined by the position of the gastric acid pocket. It was hypothesised that compounds affecting proximal stomach tone might reduce gastro-oesophageal reflux by changing the acid pocket position.
  
  
  OBJECTIVE
  To study the effect of azithromycin (Azi) on acid pocket position and acid exposure in patients with gastro-oesophageal reflux disease (GORD).
  
  
  METHODS
  Nineteen patients with GORD were included, of whom seven had a large hiatal hernia (≥3 cm) (L-HH) and 12 had a small or no hiatal hernia (S-HH). Patients were randomised to Azi 250 mg/day or placebo during 3 days in a crossover manner. On each study day, reflux episodes were detected using concurrent high-resolution manometry and pH-impedance monitoring after a standardised meal. The acid pocket was visualised using scintigraphy, and its position was determined relative to the diaphragm.
  
  
  RESULTS
  Azi reduced the number of acid reflux events (placebo 8.0±2.2 vs Azi 5.6±1.8, p<0.01) and postprandial acid exposure (placebo 10.5±3.8% vs Azi 5.9±2.5%, p<0.05) in all patients without affecting the total number of reflux episodes. Acid reflux occurred mainly when the acid pocket was located above, or at the level of, the diaphragm, rather than below the diaphragm. Treatment with Azi reduced hiatal hernia size and resulted in a more distal position of the acid pocket compared with placebo (below the diaphragm 39% vs 29%, p=0.03). Azi reduced the rate of acid reflux episodes in patients with S-HH (38% to 17%) to a greater extent than in patients with L-HH (69% to 62%, p=0.04).
  
  
  CONCLUSIONS
  Azi reduces acid reflux episodes and oesophageal acid exposure. This effect was associated with a smaller hiatal hernia size and a more distal position of the acid pocket, further indicating the importance of the acid pocket in the pathogenesis of GORD.
  
  
  BACKGROUND
  http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=1970 NTR1970.
authors.affiliation: Department of Gastroenterology and Hepatology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: W O
authors.initials: WO
authors.lastname: Rohof
authors.forename: R J
authors.initials: RJ
authors.lastname: Bennink
authors.forename: A A
authors.initials: AA
authors.lastname: de Ruigh
authors.forename: D P
authors.initials: DP
authors.lastname: Hirsch
authors.forename: A H
authors.initials: AH
authors.lastname: Zwinderman
authors.forename: G E
authors.initials: GE
authors.lastname: Boeckxstaens
mesh_terms: D000368:Aged; D017963:Azithromycin / Q000627:therapeutic use*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D005744:Gastric Acid / Q000502:physiology; D005764:Gastroesophageal Reflux / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology; D005765:Gastrointestinal Agents / Q000627:therapeutic use*; D006551:Hernia, Hiatal / Q000150:complications* / Q000188:drug therapy / Q000473:pathology; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome
chemical_list: D005765:Gastrointestinal Agents; D017963:Azithromycin