Generic Name:

Fosphenytoin Sodium

Trade Name:

Cerebyx®

Action:

Anticonvulsant

Anti-arrhythmic

Indications:

•  -           Tonic-clonic and psychomotor seizures; status epilepticus

•  -           Prevention & treatment of seizures during neurosurgery

•  -           Short-term substitute for oral phenytoin in NPO patients

•  -           Cardiac glycoside induced dysrhythmias

Administration Guidelines:

Usual Dosage Range and Route:

*IV push/infuse at a rate no greater than 150 mg PE/ minute *

Dose of fosphenytoin is expressed as the phenytoin equivalent (PE).

PROPHYLAXIS Loading Dose :

15-18 mg PE/kg (1000mg).

STATUS EPILEPTICUS or ACTIVE SEIZURE Loading dose : 15-25 mg PE/kg (maximum 30 mg PE/kg)

*LOADING DOSE IS USUALLY GIVEN PRIOR TO STARTING MAINTENANCE*

Maintenance Dose : 4-6 mg PE/kg I.V. or I.M. administered as a single daily dose or divided two to three times daily

Dilute for intravenous administration with D5W or NS to 1.5-25 mg PE/ml

Administer intravenously at a rate of 100-150 mg PE/min

Intramuscular administration must be undiluted drug

Standard Concentration:

Microinfusion syringe concentrations

500 mg PE in 20 ml

750 mg PE in 30 ml

1000 mg PE in 40 ml

1250 mg PE in 50 ml

Bag concentrations: mix all doses 301 to 1250 mg PE in 50 mls NS or D5W

Mix all doses > 1250 mg PE in 100 mls NS or D5W

Pharmacy will issue supply for doses up to and including 300 mg IVP to be given by RN at 100 mg PE/min

EW Standard

Bag concentrations: mix all doses 301 to 1250 mg PE in 50 mls NS or D5W

Mix all doses > 1250 mg PE in 100 mls NS or D5W

  All doses up to and including 300 mg IVP to be given by RN at 100 mg PE/min

Special Considerations:

•  -           Risk of soft tissue injury after extravasation is less with fosphenytoin, when compared to phenytoin.

•  -           Fosphenytoin is the prodrug of phenytoin.

•  -           Phenytoin serum levels should be monitored. Plasma levels should not be measured until conversion of phenytoin is complete, 2 hours after I.V. or infusion of 4 hours after and I.M. injection

•  -           Cardiac monitoring is needed when administering I.V. loading doses of fosphenytoin

•  -           Dosage adjustments may be required in renal or hepatic disease

•  -           In patients with hypoalbuminemia phenytoin levels should be monitored:

•  -           Calculating phenytoin level correction in hypoalbuminemia:

Corrected level= Measured phenytoin level /[(albumin x 0.2) + 0.1]

•  -           In renal failure: CrCL < 20

Corrected level= Measured phenytoin level /[(albumin x 0.1) + 0.1]

•  -           Contraindicated in sinus bradycardia, sino-atrial block, second- and third-degree AV block, Adams-Stokes Syndrome

•  -           hypersensitivity to phenytoin, hydantoins or any component of the formulation

•  -           monitor closely when converting patient from oral phenytoin preparations to IV/IM fosphenytoin

Precautions and Side Effects:

•  -           Hypotension, bradycardia, borderline heart block, EKG changes

•  -           CNS depression (nystagmus, somnolence, ataxia) hypotension, may occur at high doses or high rates of fosphenytoin

•  -           transient pruritis and parasthesias may occur and may be dose and rate relat ed.