Impact of proton pump inhibitors on cytochrome P450 activity assessed by C-aminopyrine breath test in patients with cirrhosis.

BACKGROUND

Chronic use of proton pump inhibitors (PPIs) in patients with impaired liver function may worsen cytochrome P450 (CYP450) activity, predisposing them to clinically relevant drug-drug interactions. The C-aminopyrine breath test ( C-ABT) is a non-invasive tool to study CYP450-dependent liver function.

AIMS

To assess C-ABT modifications with different PPIs in patients with cirrhosis METHODS: Sixty consecutive patients with HCV-related cirrhosis and indication to start PPI therapy were randomised to receive omeprazole 20 mg/day, esomeprazole 20 mg/day, lansoprazole 15 mg/day, pantoprazole 40 mg/day or rabeprazole 20 mg/day. C-ABT was performed at baseline and on the 15th day of PPI therapy.

RESULTS

At baseline, mean values of max C% dose/h and C% cum dose at 120 minutes did not differ significantly among groups. On the 15th day of therapy, max C% dose/h and C% cum dose at 120 minutes did not significantly differ with respect to baseline for pantoprazole (P = 0.184 and P = 0.309, respectively) or rabeprazole (P = 0.536 and P = 0.286, respectively), but were significantly decreased on omeprazole (P = 0.013 and P = 0.015, respectively), esomeprazole (P = 0.009 and P = 0.001, respectively), and lansoprazole (P = 0.033 and P = 0.035, respectively).

CONCLUSIONS

In patients with cirrhosis, omeprazole, esomeprazole and lansoprazole inhibit microsomal activity while pantoprazole and rabeprazole do not have a significant impact. Should our data be confirmed in larger cohort studies, pantoprazole and rabeprazole could be safely recommended for patients with cirrhosis.