Ability of Rabeprazole to Prevent Gastric Mucosal Damage From Clopidogrel and Low Doses of Aspirin Depends on CYP2C19 Genotype
Clinical Gastroenterology and Hepatology , 07/27/2012

Uotani T et al. – Clopidogrel and low doses of aspirin cause a similar degree of gastric mucosal damage. Rabeprazole prevented this damage without reducing the antiplatelet function of clopidogrel. However, its prophylactic effect varies with CYP2C19 genotype in H pylori–negative subjects.

• Twenty Japanese subjects with different CYP2C19 genotypes were randomly assigned to groups that were given a low dose of aspirin (100 mg; A), clopidogrel (75 mg; C), low dose of aspirin and clopidogrel (AC), or low dose of aspirin in combination with clopidogrel and rabeprazole (10 mg; ACR) once daily for 7 days.
• Subjects underwent gastroduodenoscopy and platelet tests on days 3 and 7; gastric mucosal damage was assessed by using the modified Lanza score (MLS).
• The authors performed 24–hour intragastric pH monitoring on day 7 of each regimen.
• The authors also analyzed the effects of the AC regimen on 30 patients with different CYP2C19 genotypes.

• Subjects in groups A, C, and AC had significantly higher levels of gastric mucosal damage on days 3 and 7, compared with baseline.
• The median MLS for the AC group was similar to that of the A group.
• Helicobacter pylori–negative subjects in the ACR group with different CYP2C19 genotypes had significant differences in MLS, intragastric pH, and platelet function.
• Gastric mucosal injury was inhibited equally among H pylori–positive subjects in the ACR group.
• Rabeprazole did not appear to affect platelet function or intragastric pH in subjects given clopidogrel.