Rabeprazole 10 mg q.d.s. deceases 24-h intragastric acidity significantly more than rabeprazole 20 mg b.d. or 40 mg o.m., overcoming CYP2C19 genotype
Alimentary Pharmacology and Therapeutics, 08/17/2012
Sugimoto M et al. – Four times daily dosing with rabeprazole 10 mg achieved potent acid inhibition, including during the night–time, suggesting its potential usefulness as a regimen for patients who are refractory to standard once daily PPI treatment.Methods
- Using pH monitoring, the authors evaluated the efficacy of different divided treatment regimens with the same total daily dose of rabeprazole (40 mg o.m., 15 rounds; 20 mg b.d., 20 rounds; 10 mg q.d.s., 35 rounds) on day 7 or 8 of PPI dosing.
- In the study of divided treatment, the median pH (when administered once, twice or four times to achieve a daily dose of 40 mg) was 4.8 (3.6-6.4), 5.7 (4.1-7.4), 6.6 (4.9-8.4), respectively.
- When comparing the median pHs at the same CYP2C19 genotype among different dosing times of rabeprazole, the median pH attained with 10 mg q.d.s. was significantly higher than that in 40 mg o.m. or 20 mg b.d.
- Increase in the frequency of dosing effectively increased pH [median percent time of pH > 4.0 with q.d.s. therapy: 95.5% (63.2-100.0%)], irrespective to CYP2C19 genotype.