Kinetics of Phenytoin in Pregnant and Non‐pregnant Rats

Abstract

Abstract The plasma kinetics of phenytoin were studied in pregnant and nonpregnant rats after a single intravenous dose. The apparent volume of distribution was greater in the pregnant rats resulting in lower plasma concentrations in these rats within the first hour of injection. The beta half‐life in pregnant rats (5.0 hours) was prolonged compared to the non‐pregnant rats (2.2 hours). The plasma clearance values which take the altered volume of distribution into account, showed a smaller but still significant difference between the two groups of rats. This indicates a lower capacity of the pregnant rats to metabolize the drug.