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Fosphenytoin Dosage

Medically reviewed by Drugs.com. Last updated on May 20, 2022.

Applies to the following strengths: 100 mgPE/2 mL; 500 mgPE/10 mL

Usual Adult Dose for Status Epilepticus

Loading dose: 15 to 20 mg PE/kg IV; infuse at 100 to 150 mg PE/min


Maintenance dose: 4 to 6 mg PE/kg/day in divided doses at a rate no greater than 150 mg PE/min

Comments:

Use: For the treatment of generalized tonic-clonic status epilepticus

Usual Adult Dose for Epilepsy

Loading dose: 10 to 20 mg PE/kg IV; infuse at a rate no greater than 150 mg PE/min


Maintenance dose: 4 to 6 mg PE/kg/day IV in divided doses at a rate no greater than 150 mg PE/min

Comments:

Uses:

Usual Pediatric Dose for Status Epilepticus

Cerebyx:
Less than 17 years:
Loading dose: 15 to 20 mg PE/kg IV; infuse at 2 mg PE/min (or 150 mg PE/min, whichever is slower)

Maintenance Dose:


17 years or older: See Adult Dosing

Comments:

Use: For the treatment of generalized tonic-clonic status epilepticus (Cerebyx only)

Usual Pediatric Dose for Epilepsy

Cerebyx:
Less than 17 years:
Loading Dose: 10 to 15 mg PE/kg IV; infuse at 1 to 2 mg PE/kg/min or 150 mg PE/min, whichever is slower

Maintenance Doses:


17 years or older: See Adult Dosing

Comments:

Use: Prevention and treatment of seizures occurring during neurosurgery (Cerebyx)

SUBSTITUTION FOR ORAL PHENYTOIN: When treatment with oral phenytoin is not possible, IV fosphenytoin can be substituted for oral phenytoin at the same total daily phenytoin sodium equivalents (PE) dose.

Renal Dose Adjustments

Use with caution; monitor unbound phenytoin concentrations

Severe Renal Impairment (eGFR 15 to 29 mL/min/1.73 m2):

Liver Dose Adjustments

Use with caution; monitor unbound phenytoin concentrations

Dose Adjustments

Elderly: A lower dose or less frequent dosing may be needed as the clearance of phenytoin is decreased slightly in elderly patients

Monitoring Phenytoin Levels:


Monitoring Phenytoin Levels in Patients with Hypoalbuminemia (including patients with renal or hepatic impairment) and When Used During Pregnancy:

Precautions

US BOXED WARNINGS: Cardiovascular Risk Associated with Rapid Infusion Rates:


Safety and efficacy of Sesquient have not been established in patients younger than 2 years.

Consult WARNINGS section for additional precautions.

Dialysis

Data not available

Other Comments

Administration advice:
For IV infusion; do not exceed IV infusion rates due to cardiovascular risks


DOSING ERRORS:

Storage requirements:

Reconstitution/preparation techniques:

General:

Monitoring:

Patient advice:

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.