DRUG | SUPPLIED | DOSE | COMMENTS |
---|---|---|---|
FOSPHENYTOIN (Paeds) (Cerebyx) Mechanism of action: Anticonvulsant; phosphate ester prodrug for phenytoin; sodium channel blocker Ref: 32, 44, 82, 174, 175 Last update: 2022-07-02 |
Injection: 50 mg PE/mL (=75 mg/mL fosphenytoin sodium) PE = phenytoin equivalents |
Status Epilepticus: Loading Dose: 20 mg PE/kg/dose IM/IV (Max: 1500 mg PE/dose). May give additional load of 5-10 mg PE/kg/dose IM/IV after 10 mins if not resolved. Initial Maintenance for Seizure Disorder: Infants, Children, and Adolescents: 2.5 mg PE/kg/dose IM/IV Q12H or 1.7 mg PE/kg/dose IM/IV Q8H (Max: 300 mg PE/24 hr) (Usual range: 4-10 mg PE/kg/24 hr; Neonates and infants may require Q8H dosing up to 10 mg PE/kg/24 hr) |
Avoid if allergy to aromatic hydrocarbons (carbamazepine, oxcarbazepine, phenytoin, lamotrigine). i) No IV/IO access available ii) IV access is tenuous and extravasation will result in significant morbidity iii) IV phenytoin not tolerated PE = phenytoin sodium equivalents Treatment duration >5 days not evaluated. At higher serum concentrations, small dose increases can result in disproportionately high serum levels. IV administration rate up to 3 mg PE/kg/min or 150 mg PE in patients >50 kg. Adverse effects: Ataxia, nystagmus, somnolence, Steven Johnson Syndrome (rare), hypotension (IV). Post load (phenytoin) level taken 4 hours after IM load or 2 hours after IV load. Target serum concentration: 40-80 mcmol/L. Refer to Therapeutic Drug Monitoring (white pages in hard copy). Standard Prescription: fosphenytoin__mg PE IM/IV x 1 loading dose (__mg PE/kg/dose) fosphenytoin__mg PE IM/IV Q__H (__mg PE/kg/24h) |