We highly recommend enabling Javascript while using the BlackBoxRX site.

Fosphenytoin Sodium

Cardiovascular RIsk Associated with Rapid Infusion Rates

  • The rate of intravenous fosphenytoin administration should not exceed 150 mg phenytoin sodium equivalents (PE) per minute because of the risk of severe hypotension and cardiac arrhythmias.
  • Careful cardiac monitoring is needed during and after administering intravenous fosphenytoin. Although the risk of cardiovascular toxicity increases with infusion rates above the recommended infusion rate, these events have also been reported at or below the recommended infusion rate.
  • Reduction in rate of administration or discontinuation of dosing may be needed (see WARNINGS and DOSAGE AND ADMINISTRATION).
  • A history of hypersensitivity to CEREBRYX, or its inactive ingredients, or to phenytoin or other hydantoins. ┬áReactions have included angioedema.

Patient Counseling Information

Package Inserts


Updated August 2019