[Effect of High-Altitude Hypoxia on the Pharmacokinetics and Brain Distribution of Phenytoin Sodium in Epileptic Rats].

The hypoxic environment at high altitudes can promote the metabolism of phenytoin sodium, reduce its absorption efficiency, and change the characteristics its distribution in the brain, which may be related to the up-regulation of the expression of CYP2C9 in the liver and that of P-gp in the brain.