(Fosphenytoin Sodium Injection)
Cerebyx® (fosphenytoin sodium injection) is a prodrug intended for parenteral administration; its active metabolite is phenytoin. Each Cerebyx vial contains 75 mg/mL fosphenytoin sodium (hereafter referred to as fosphenytoin) equivalent to 50 mg/mL phenytoin sodium after administration. Cerebyx is supplied in vials as a ready-mixed solution in Water for Injection, USP, and Tromethamine, USP (TRIS), buffer adjusted to pH 8.6 to 9.0 with either Hydrochloric Acid, NF, or Sodium Hydroxide, NF. Cerebyx is a clear, colorless to pale yellow, sterile solution.
Cerebyx is indicated for short-term parenteral administration when other means of phenytoin administration are unavailable, inappropriate or deemed less advantageous. The safety and effectiveness of Cerebyx in this use has not been systematically evaluated for more than 5 days.
Cerebyx can be used for the control of generalized convulsive status epilepticus and prevention and treatment of seizures occurring during neurosurgery. It can also be substituted, short-term, for oral phenytoin.
Published Studies Related to Cerebyx (Fosphenytoin)
Initial EEG predicts outcomes in a trial of levetiracetam vs. fosphenytoin for
seizure prevention. 
Continuous electroencephalography (cEEG) is increasingly used to detect both
clinical and subclinical seizures in patients with traumatic brain injury (TBI)
or subarachnoid hemorrhage (SAH). We assess whether EEG findings predict outcomes
in TBI/SAH patients enrolled in a levetiracetam (LEV) vs... While it has been
shown that LEV is associated with better outcome than fos-PHT when used as
seizure prophylaxis in brain injury, aside from severity of generalized slowing,
electrographic findings of focal slowing, epileptiform discharges, and seizures
were not themselves associated with outcomes in patients with TBI or SAH enrolled
in a randomized clinical trial.
Blood pressure changes after intravenous fosphenytoin and levetiracetam in patients with acute cerebral symptoms. [2009.12]
PURPOSE: To study the incidence and extent of the occasionally noted hypotension after intravenous (IV) infusions of fosphenytoin (FOS) and levetiracetam (LEV) in patients presenting with acute cerebral symptoms... CONCLUSIONS: IV infusion of FOS in subjects presenting with acute cerebral symptoms may cause significant decreases in their blood pressure. This was not seen in patients receiving IV LEV infusions. Since maintaining adequate cerebral perfusion pressure is a key point in the management of patients with acute cerebral symptoms, the results of this study may carry a clinical impact on the management of this subgroup of patients.
BACKGROUND: Fosphenytoin, phosphate ester pro-drug of phenytoin, was developed to overcome complications associated with parenteral phenytoin administration in treatment of acute symptomatic seizures, short-term prophylaxis and treatment of repetitive or prolonged seizures and status epilepticus. OBJECTIVE: To evaluate the current position of fosphenytoin in treatment algorithms compared to phenytoin... CONCLUSION: Published literature shows that intravenous fosphenytoin has a similar adverse effect profile than phenytoin when it is administered as recommended. There is no evidence of clear benefit that would justify the higher price of the fosphenytoin compared to phenytoin.
Fosphenytoin may cause hemodynamically unstable bradydysrhythmias. [2006.01]
The prodrug fosphenytoin (FOS) was recently introduced as an alternative to phenytoin (PTN) and has since become a first line therapy for status epilepticus...
Hyperphosphatemia due to fosphenytoin in a pediatric ESRD patient. [2005.08]
Fosphenytoin is indicated for the treatment of generalized convulsions and seizures occurring during neurosurgery.Due to this risk of hyperphosphatemia, we recommend that fosphenytoin should be used with caution in the end-stage renal disease population.
Clinical Trials Related to Cerebyx (Fosphenytoin)
Intravenous Lacosamide Compared With Fosphenytoin in the Treatment of Patients With Frequent Nonconvulsive Seizures [Recruiting]
This a phase 2 study comparing the efficacy of intravenous (IV) lacosamide (LCM) with IV
fosphenytoin (fPHT) in controlling frequent nonconvulsive seizures (NCSs), the Adverse
Events profile of LCM compared with fPHT when used to treat frequent NCSs, and length of
stay in an intensive care unit for subjects treated with LCM versus subjects treated with
fPHT. The trial will include a preacute-treatment period, an acute-treatment period, and a
The Study of NPC-06 - Investigation of Safety, Efficacy and Pharmacokinetics of Fosphenytoin [Recruiting]
The study is to evaluate safety, efficacy and pharmacokinetics of intravenously administered
fosphenytoin in patients with neurosurgery, head trauma, epilepsy or status epilepticus who
are requiring a loading dose of phenytoin.
A Pilot Study of NSICU Assessment of Seizure Prophylaxis With Lacosamide [Recruiting]
Trial to determine if seizure prophylaxis with IV LCM in NSICU patients experiencing mental
status changes due to severe traumatic brain injury (sTBI) will result in improved short-
and long-term outcomes and better immediate adverse effects when compared to the current
standard of care anticonvulsant (IV fPHT) and will be at least as effective as IV fPHT in
preventing clinical and sub-clinical seizure activity.
IV Keppra in the Emergency Department for Prevention of Early Recurrent Seizures [Recruiting]
This study is looking at three seizure medicines. Patients with seizures are usually treated
with phenytoin (Dilantin)or Fosphenytoin. These medicines can be given by IV or by mouth.
Another seizure medicine, levetiracetam (Keppra) can now be given this way also. This study
will compare IV phenytoin (Dilantin)and IV fosphenytoin to levetiracetam (Keppra) in patients
who have had a recent seizure. Only patients with a history of seizures can be involved.
The patient must present to the emergency department within 4 hours of a seizure. The
purpose of this study is to compare these three drugs, phenytoin (Dilantin), fosphenytoin,
and levetiracetam (Keppra). The investigators are looking to see if these drugs can prevent
another seizure in the next 24 hours. We are also looking fro any possible side effects.
Antiepileptic Drugs and Vascular Risk Markers [Recruiting]
The purpose of this study is to determine if certain seizure medications raise levels of
cholesterol and other blood components which could increase the risk of heart attacks and