It is used to treat or prevent seizures

It can cause hepatic necrosis, ataxia, confusion, constipation, depression, dizziness, drowsiness, fatigue, hypertrichosis, mental status changes, myasthenia, nervousness, numbness, tremor, tremor of hands, vertigo, excitement, irritability, mood changes, and restlessness.

Hypersensitivity to the drug and patients with Hepatic disease, sinus bradycardia, AV block

Use caution in cardiovascular disease, hypoalbuminemia, hepatic impairment, hypothyroidism, or seizures; because fraction of unbound phenytoin is increased in patients with renal or hepatic disease, or in those with hypoalbuminemia, the monitoring of phenytoin serum levels should be based on the unbound fraction in those patients

Decreased bone mineral density reported with chronic use

Careful cardiac monitoring is needed during and after IV administration

May cause fetal harm when administered to a pregnant woman

This drug may pose risks to your pregnancy, therefore please do not take this medicine without consulting your doctor first.

Drugs that may interact with this medicine include Cyclosporin, dopamine, erythromycin, itraconazole, lansoprazole.