Durazol Mechanism of Action

Pharmacology: Pharmacokinetics: Pantoprazole is rapidly variably absorbed following oral administration. Absorption is not affected by food. Pantoprazole is acid-labile and pharmacokinetics may vary between the various formulations developed to improve oral bioavailability. The absorption of pantoprazole also appears to be dose-dependent, increasing the dosage above 40 mg has been reported to increase the plasma concentrations in a non-linear fashion because of saturable first-pass hepatic metabolism. In addition, absorption is higher after long-term administration. Bioavailability of pantoprazole may be increased in elderly patients, in some ethnic groups, such as Chinese, and in patients with impaired hepatic function, but is not markedly affected in patients with renal impairment.
Following absorption pantoprazole is almost completely metabolized in the liver, primarily by the cytochrome P450 isoenzyme CYP2C19, to des-methylpantoprazole; small amounts are also metabolized by CYP3A4, CYP2D6, and CYP2C9. Metabolites are excreted mainly (about 80%) in the urine, with the remainder being excreted in the bile. The terminal elimination half-life is about 1 hour and is prolonged in hepatic impairment, the half-life in patients with cirrhosis was 3 to 6 hours.