title: Monitoring cytochrome P-450 activity during rabeprazole treatment in patients with gastresophageal reflux disease.
abstract: Proton pump inhibitors (PPIs) are the cornerstone in the treatment of gastresophageal reflux disease (GORD). PPIs are metabolized by the hepatic cytochrome P-450 enzymes (CYP-450). Rabeprazole is a PPI whose metabolism shows fewer interactions compared to other PPIs. In this study we evaluated the influence of rabeprazole administration on hepatic CYP-450 activity as measured by the (13)C-aminopyrine breath test ((13)C-ABT) in a group of patients with GORD. (13)C-ABT was performed on five GORD patients both before and after 1 week of rabeprazole administration (20 mg, b.i.d.). Pretreatment (13)C-ABT results were compared to posttreatment results. Pre- and posttreatment (13)C-ABT results for patients were compared to those obtained in five controls who did the test twice, with a 1-week interval in between. Before treatment, the (13)C-ABT results for the GORD patients did not significantly differ from those of healthy subjects. After treatment, we observed no significant modification of the (13)C-ABT in GORD patients compared to pretreatment values ((13)C-ABT %dose/hr, 10.56+/-1.31 versus 11.17+/-0.88; (13)C-ABT %cumulative dose, 8.08+/-1.11 versus 8.34+/-0.56). Posttreatment (13)C-ABT results were not significantly different from those obtained in controls at weekly repetition of the test. In patients with GORD, 1-week, full-dose rabeprazole does not display any significant interactions with CYP-450 activity.
authors.affiliation: Gastroenterology Unit, Department of Internal Medicine, University of Genoa, Viale Benedetto XV, no. 6, 16132 Genoa, Italy. egiannini@unige.it
authors.forename: Edoardo G
authors.initials: EG
authors.lastname: Giannini
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Savarino
authors.forename: Roberto
authors.initials: R
authors.lastname: Testa
mesh_terms: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000632:Aminopyrine; D000894:Anti-Inflammatory Agents, Non-Steroidal; D000897:Anti-Ulcer Agents / Q000627:therapeutic use*; D001562:Benzimidazoles / Q000627:therapeutic use*; D001944:Breath Tests; D016022:Case-Control Studies; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D005260:Female; D005764:Gastroesophageal Reflux / Q000188:drug therapy* / Q000201:enzymology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D009853:Omeprazole / Q000031:analogs & derivatives* / Q000627:therapeutic use; D064750:Rabeprazole; D016896:Treatment Outcome
chemical_list: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000894:Anti-Inflammatory Agents, Non-Steroidal; D000897:Anti-Ulcer Agents; D001562:Benzimidazoles; D000632:Aminopyrine; D064750:Rabeprazole; D003577:Cytochrome P-450 Enzyme System; D009853:Omeprazole