Aciphex
Effects of rabeprazole sodium on gastric emptying, electrogastrography, and fullness.

Jones MP, Shah D, Ebert CC.

Division of Gastroenterology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.

Proton pump inhibitors have been reported to delay gastric emptying, but this effect is controversial. Our aim was to determine the effect of rabeprazole sodium on several parameters of gastric function including gastric emptying, myoelectrical activity and ingested water volume required to produce fullness. Fifteen healthy males underwent assessment of solid-phase gastric emptying with the [13C] Spirulina platensis breath test as well as electrogastrography and satiety testing using a 5-min water load. Subjects were evaluated at baseline, after administration of placebo, and after rabeprazole sodium 20 mg daily for one week. No significant differences were seen between groups with respect to solid-phase gastric emptying as measured by T1/2 or T(lag). No differences were seen between baseline, placebo, and rabeprazole with respect to the number of normal electrogastrograms and the volume of water required to produce fullness. In conclusion, one week of therapy with rabeprazole sodium does not significantly alter gastric emptying, myoelectrical activity or threshold to fullness.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12645792&dopt=Abstract rabeprazole Aciphex



Aciphex
A proton-pump inhibitor, rabeprazole, improves ventilatory function in patients with asthma associated with gastroesophageal reflux.

Tsugeno H, Mizuno M, Fujiki S, Okada H, Okamoto M, Hosaki Y, Ashida S, Mitsunobu F, Tanizaki Y, Shiratori Y.

Dept. of Medicine, Misasa Medical Center, Okayama University Medical School, Misasa, Tottori, Japan. attractively21 yahoo.co.jp

BACKGROUND: Treatment of gastroesophageal reflux (GER) with proton-pump inhibitors (PPI) improves symptoms of asthma in some patients. However, the effects of a PPI on ventilatory function are still controversial. In this study, we measured ventilatory function in asthma patients treated with a PPI in order to identify those in whom a therapeutic effect on asthma can be expected from the acid suppression. METHODS: From a cohort of 114 consecutive patients with bronchial asthma, 53 patients agreed to participate in the study and were treated with rabeprazole 20mg daily for 8 weeks during an asymptomatic, stable period with no exacerbations of their asthma. Of the 53 patients, 22 were diagnosed as GER on the basis of the QUEST questionnaire and endoscopic examination. The patients were monitored for improvement in ventilatory function. RESULTS: Four patients dropped out because of adverse drug reactions. All the patients with GER noted an improvement in reflux symptoms with PPI treatment. An improvement of more than 20% in peak expiratory flow (PEF) was observed in 8 of 21 GER patients but in none of the non-GER patients. Factors predictive of improvement in PEF with rabeprazole therapy were the QUEST score (odds ratio: 1.47, 95% CI: 1.06-2.04, P = 0.022) and steroid-dependency of asthma (odds ratio: 0.01, 95% CI: 0.001-0.31, P = 0.008). CONCLUSIONS: Treatment with rabeprazole is expected to ameliorate asthma in non-steroid-dependent patients who have symptomatic GER defined by the QUEST score.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12795453&dopt=Abstract rabeprazole Aciphex



Aciphex
Time-dependent amplified pharmacokinetic and pharmacodynamic responses of rabeprazole in cytochrome P450 2C19 poor metabolizers.

Lin CJ, Yang JC, Uang YS, Chern HD, Wang TH.

Graduate Institute of Clinical Pharmacy, College of Medicine, National Taiwan University, Taipei.

STUDY OBJECTIVES: To determine the pharmacokinetic and pharmacodynamic rationale for the optimum regimen of rabeprazole in the treatment of Helicobacter pylori infection in patients who are cytochrome P450 (CYP) 2C19 poor metabolizers or extensive metabolizers. DESIGN: Prospective, multiple-dose pharmacokinetic and pharmacodynamic study. SETTING: University-affiliated medical center in Taiwan. SUBJECTS: Twelve healthy volunteers (aged 20-30 yrs) who were identified as CYP2C19 poor metabolizers (six subjects) or extensive metabolizers (six). INTERVENTION: Each subject received rabeprazole 20 mg twice/day for 3 consecutive days and once/day on the fourth day. MEASUREMENTS AND MAIN RESULTS: Pharmacokinetic and pharmacodynamic parameters were compared between CYP2C19 poor and extensive metabolizers on day 1 and day 4 of dosing. The mean +/- SD values of area under the concentration-time curve of rabeprazole and rabeprazole thioether were significantly higher in poor metabolizers than in extensive metabolizers on day 1 (5357 +/- 883 vs 1131 +/- 512 ng x hr/ml and 1703 +/- 432 vs 561 +/- 358 ng x hr/ml, respectively; p<0.001) and on day 4 (5601 +/- 669 vs 1619 +/- 778 ng x hr/ml and 1914 +/- 378 vs 511 +/- 360 ng x hr/ml, respectively; p<0.001). However, no significant difference was noted between day 1 and day 4 of dosing within the same genotype groups. Only CYP2C19 poor metabolizers had significantly higher plasma gastrin levels on day 4 compared with those levels on day 1 (p<0.05). The pharmacokinetic-pharmacodynamic relationship of rabeprazole appears to be time dependent. CONCLUSION: The pharmacokinetic and pharmacodynamic data suggest that CYP2C19 poor metabolizers might be subject to advantageous conditions, especially after day 4, for treating H. pylori infection with rabeprazole.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12820812&dopt=Abstract rabeprazole Aciphex