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Clinical Pharmacology
PROTONIX (pantoprazole sodium) Delayed-Release Tablets only
CLINICAL PHARMACOLOGY Pharmacokinetics Text Continues Below
PROTONIX is prepared as an enteric-coated tablet so that absorption of pantoprazole begins only after the tablet leaves the stomach. Peak serum concentration (Cmax) and area under the serum concentration time curve (AUC) increase in a manner proportional to oral and intravenous doses from 10 mg to 80 mg. Pantoprazole does not accumulate and its pharmacokinetics are unaltered with multiple daily dosing. Following oral or intravenous administration, the serum concentration of pantoprazole declines biexponentially with a terminal elimination half-life of approximately one hour. In extensive metabolizers (see Metabolism section) with normal liver function receiving an oral dose of the enteric-coated 40 mg pantoprazole tablet, the peak concentration (Cmax) is 2.5 µ g/ mL, the time to reach the peak concentration (tmax) is 2.5 h and the total area under the plasma concentration versus time curve (AUC) is 4.8 µ g· hr/ mL. When pantoprazole is given with food, its tmax is highly variable and may increase significantly. Following intravenous administration of pantoprazole to extensive metabolizers, its total clearance is 7.6-14.0 L/ h and its apparent volume of distribution is 11.0-23.6L. Absorption The absorption of pantoprazole is rapid, with a Cmax of 2.5 µ g/ mL that occurs approximately 2.5 hours after single or multiple oral 40-mg doses. Pantoprazole is well absorbed; it undergoes little first-pass metabolism resulting in an absolute bioavailability of approximately 77%. Pantoprazole absorption is not affected by concomitant administration of antacids. Administration of pantoprazole with food may delay its absorption up to 2 hours or longer; however, the Cmax and the extent of pantoprazole absorption (AUC) are not altered. Thus, pantoprazole may be taken without regard to timing of meals. Page: 1 | 2 | 3 | Next >>
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