Phenytoin
Brand: Dilantin, Phenytek
No boxed warning on the current FDA label.
- Caution
- Narrow therapeutic index; injection given too fast causes severe hypotension and arrhythmias (the injection carries a boxed warning, the oral forms do not).
- Pregnancy
- Avoid if possible: fetal hydantoin syndrome (birth defects).
Common side effects
- Overgrowth of the gums
- Unsteadiness and slurred speech
- Involuntary eye movement
- Rash
Key interactions
- Induces liver enzymes: lowers contraceptive and warfarin levels
- Tube feeds reduce absorption
- Many drugs shift its free level
Counseling points
- Good oral hygiene reduces gum overgrowth
- Blood levels are followed closely
- Report rash, unsteadiness, or slurred speech
- Do not switch between brands without advice
We ask 6 questions about Phenytoin.Practice Phenytoin →Test yourself on medications like Phenytoin.Practice Medications →
High-yield study aid for exam prep, not a substitute for the package insert or a pharmacist’s dispensing reference.