Correct Way to Load Cerebyx (Fosphenytoin)

The correct way to load Cerebyx (fosphenytoin) is to administer 18 PE/kg IV at a maximum rate of 150 PE/min for adults. 1, 2

Dosing Guidelines

For status epilepticus in adults, administer a loading dose of 15-20 mg PE/kg IV at a rate of 100-150 mg PE/min 2
For pediatric patients with status epilepticus, administer 15-20 mg PE/kg at a rate of 2 mg PE/kg/min (or 150 mg PE/min, whichever is slower) 2
Intramuscular administration is not recommended for status epilepticus 2

For non-emergent situations in adults, administer a loading dose of 10-20 mg PE/kg IV or IM 2
Initial maintenance dose is 4-6 mg PE/kg/day in divided doses 2
For pediatric patients, use a loading dose of 10-15 mg PE/kg at a rate of 1-2 mg PE/kg/min (or 150 mg PE/min, whichever is slower) 2

Careful cardiac monitoring is required during and after IV administration due to risk of hypotension and cardiac arrhythmias 2
Monitor vital signs closely, especially blood pressure and heart rate via ECG 1
Reduce the rate of infusion if heart rate decreases by 10 beats per minute 1

Fosphenytoin can be administered faster than phenytoin (150 PE/min vs. 50 mg/min) 1, 3
Associated with fewer adverse events compared to IV phenytoin loading 1
Can be administered intramuscularly when IV access is unavailable 3
Fewer local reactions such as phlebitis, purple glove syndrome, and tissue necrosis 3

Transient paresthesias and pruritus may occur with rapid infusion rates 3
Other common adverse reactions include nystagmus, dizziness, somnolence, and ataxia 2
In pediatric patients, vomiting, nystagmus, and ataxia are most common 2

For patients with renal or hepatic disease, hypoalbuminemia, or elderly patients, consider reducing the infusion rate by 25-50% 3
These patients may experience earlier and higher unbound phenytoin plasma concentrations, increasing risk of systemic adverse effects 3

After IV administration, therapeutic phenytoin levels (>10 mcg/mL) are typically achieved within minutes after completion of the infusion 1
After IM administration, therapeutic phenytoin levels are generally observed within 30 minutes 3
Higher weight-based loading doses (closer to 19 mg/kg) are more likely to achieve therapeutic levels after initial loading 4

Do not confuse the amount of drug to be given in PE with the concentration of the drug in the vial 2
Never exceed the maximum recommended infusion rate due to risk of severe hypotension and cardiac arrhythmias 2
Do not administer fosphenytoin to patients with sinus bradycardia, sino-atrial block, second and third degree A-V block, or Adams-Stokes syndrome 2
Avoid in patients with history of hypersensitivity to fosphenytoin, phenytoin, or hydantoins 2
Do not administer with solutions containing glucose as this may cause precipitation 5