A 29-year-old female has just become pregnant and is at the doctor's office for her first pre-natal exam. This is the first time this patient has been seen by the ob-gyn. In reviewing the patients medical records the physician discovers that the woman takes Dilantin (phenytoin) to mcontrol her epileptic seizures. The physician recommends that the woman stop the Dilantin and switch to Carbatrol (carbamazepine). If the woman refuses to comply with the change in seizure medication which of the following is most likely to be defective in her newborn resulting in potentially fatal bleeding episodes?

Question

Quizplus · Accepted Answer

Phenytoin can cause vitamin K deficiency in the newborn, leading to impaired γ-carboxylation of glutamate residues in clotting factors, which is necessary for normal blood coagulation. This can result in potentially fatal bleeding episodes. The hydantoin class (includes phenytoin) of anti-seizure medications interfere with the activity of vitamin K. Loss of vitamin K, as a co-factor, leads to reduced hepatic g-carboxylation of glutamate residues in the coagulation factors II, VII, IX, X and also protein C and protein S. The net effect is defective, potentially fatal, bleeding disorder in a neonate.

A 29-Year-Old Female Has Just Become Pregnant and Is at the Doctor's