Phenytoin dosing/interactions

Drugs that increase Phenytoin levels:

Amiodarone

Cimetidine

Fluoxetine

Omeprazole

Oxacarbazepine

Ticlodipine

Phenytoin decrease drug levels:

Amiodarone

Corticosteroids

Fluconazole

Fluoxetine

Itraconazole

OCP

PIs

Warfarin

Phenytoin toxicity

- therapeutic range (10 - 20 mcg/mL)

- nystagmus on far lateral gaze

- blurred vision, diplopia, ataxia, slurred speech, dizziness, drowsiness, coma.

Refer phenytoin flow chart