Home About
Back to Search

Fosphenytoin Sodium

FOSPHENYTOIN SODIUM

Manufacturer: West-Ward Pharmaceuticals Corp

Score: 141.0

Quick Summary

Fosphenytoin sodium injection is used for the treatment of generalized tonic-clonic status epilepticus and prevention and treatment of seizures occurring during neurosurgery. It is a prodrug of phenytoin and its anticonvulsant effects are attributable to phenytoin. The precise mechanism by which phenytoin exerts its therapeutic effect has not been established but is thought to involve the voltage-dependent blockade of membrane sodium channels resulting in a reduction in sustained high-frequency neuronal discharges. The rate of intravenous administration should not exceed 150 mg phenytoin sodium equivalents (PE) per minute in adults and 2 mg PE/kg/min (or 150 mg PE/min, whichever is slower) in pediatric patients due to the risk of severe hypotension and cardiac arrhythmias.

Key Clinical Findings and Indications

  • Treatment of generalized tonic-clonic status epilepticus
  • Prevention and treatment of seizures occurring during neurosurgery
  • Substitution for oral phenytoin when oral administration is not possible

Important Safety Information

Warning

The rate of intravenous administration should not exceed 150 mg phenytoin sodium equivalents (PE) per minute in adults and 2 mg PE/kg/min (or 150 mg PE/min, whichever is slower) in pediatric patients due to the risk of severe hypotension and cardiac arrhythmias.

Contraindications

  • Hypersensitivity to fosphenytoin sodium injection or its inactive ingredients
  • Sinus bradycardia, sino-atrial block, second and third degree A-V block, or Adams-Stokes syndrome
  • A history of prior acute hepatotoxicity attributable to fosphenytoin sodium injection or phenytoin
  • Coadministration with delavirdine

Adverse Reactions

  • Nystagmus
  • Dizziness
  • Pruritus
  • Somnolence
  • Ataxia

Dosing Recommendations

General Guidance

Dose adjustments should be made based on serum phenytoin concentrations and clinical response.

Status Epilepticus

Adult Dose

15 to 20 mg PE/kg at a rate of 100 to 150 mg PE/min

Pediatric Dose

15 to 20 mg PE/kg at a rate of 2 mg PE/kg/min (or 150 mg PE/min, whichever is slower)

Non-emergent Loading and Maintenance Dosing

Adult Dose

10 to 20 mg PE/kg given IV or IM; initial maintenance dose is 4 to 6 mg PE/kg/day in divided doses

Pediatric Dose

10 to 15 mg PE/kg at a rate of 1 to 2 mg PE/kg/min (or 150 mg PE/min, whichever is slower); initial maintenance dose is 2 to 4 mg PE/kg every 12 hours

Special Population Considerations

Pregnancy

  • Prenatal exposure to phenytoin may increase the risks for congenital malformations and other adverse developmental outcomes
  • Periodic measurement of serum phenytoin concentrations is recommended during pregnancy

Nursing Mothers

Pediatric Use

  • Fosphenytoin sodium injection is indicated for the treatment of generalized tonic-clonic status epilepticus and prevention and treatment of seizures occurring during neurosurgery in all pediatric age groups
  • The rate of administration should not exceed 2 mg PE/kg/min (or 150 mg PE/min, whichever is slower) in pediatric patients

Geriatric Use

  • No systematic studies in geriatric patients have been conducted
  • Phenytoin clearance tends to decrease with increasing age; lower or less frequent dosing may be required

Similar Drugs

Fosphenytoin Sodium

FOSPHENYTOIN

Amneal Pharmaceuticals LLC

Similarity: 88.2%
Back to Search