Pharmacokinetics and metabolism of the proton pump inhibitorpantoprazole in man

Pantoprazole, a second-generation proton pump inhibitor, is absorbed after oral administration as enteric-coated tablet with maximum plasma concentrations within 2-3 h and a bioavailability of 77%. Food has no relevant effect on absorption. The pharmacokinetics of pantoprazole are dose linear in the therapeutic range. The parent drug is totally metabolized, mainly by the polymorphically expressed CYP2C19 and by CYP3A. The pharmacokinetic profile is practically unchanged after multiple dosing, as is expected for a drug with a short half-life of about 1 h. A lack of pharmacokinetic interactions with various drugs has been shown. No clinically relevant changes in the pharmacokinetics of pantoprazole are observed in elderly subjects and patients with severe renal insufficiency. However, clearance is decreased in poor metabolizers of (S)-mephenytoin and in patients with liver cirrhosis.