Medicine
Pharmacokinetic Drug Interactions with Antiepileptic Drugs
Quick fact
Phenytoin, a widely used AED, is a potent inducer of several CYP450 enzymes, which can reduce the blood levels of oral contraceptives, leading to unintended pregnancies in women taking both.
Why this is interesting
You take a common AED for seizures, and suddenly your blood pressure medication stops working—or becomes dangerously potent. Why would a seizure drug change the effect of an unrelated medicine?