NAME OF DRUG
phenytoin sodium

CLASSIFICATION

Anticonvulsant-antiarrhythmic diphenylhydantoin

ALTERNATE NAME

DILANTIN

INDICATIONS

• treatment of status epilepticus, and control /prevention of seizures
• treatment of ventricular arrhythmias due to digoxin in persons refractory or hypersensitive to conventional therapy

RECONSTITUTION AND STABILITY

• stable at room temperature
• a faint yellow color has no effect on potency
• if refrigerated a precipitate may form; this dissolves on standing at room temperature and is still suitable for use

COMPATIBILITY

• compatible with NS or 0.45% sodium chloride for 4 hours at a concentration of 1 mg/mL and for 24 hours at a concentration of 5-20 mg/mL (e.g. 1000 mg in 50-200 mL NS)
• NOT COMPATIBLE WITH D5W
• incompatible with other drugs
• if administered into a heparin lock or Y set, the set must be flushed with 10 mL of NS before and after the injectio

ROUTES OF ADMINISTRATION

DO NOT ADMINISTER PHENYTOIN THROUGH PICC LINES AS IT WILL PRECIPITATE AND BLOCK THE LINE

• IV direct 
  • maximum rate 50 mg/minute (25 mg/minute in elderly and patients with cardiac disease)
  • DO NOT ADMINISTER PHENYTOIN THROUGH PICC LINES
• IV intermittent 
  • dilute with NS or 0.45% NaCl as above and administer over 15-30 minutes (maximum rate of 50 mg/minute e.g. 1000mg in 50 mL NS over 20 minutes; 25 mg/minute in elderly and patients with cardiac disease)
  • DO NOT ADMINISTER PHENYTOIN THROUGH PICC LINES
• IM - NOT RECOMMENDED (erratic and delayed absorption)

VH & HSC ADMINISTRATION POLICY

E - Direct IV route can be administered by nurses on general nursing units provided a venous access has been established, and according to policies and recommendations stated in this manual.

H - Doses > 500 mg must be administered via an automated infusion control device.

DOSAGE

ADULTS

Status epilepticus:

• Loading dose - 15-18 mg/kg IV at a maximum rate of 50 mg/minute
• Maintenance dose - 5-7 mg/kg IV daily: divided doses are recommended

Cardiac arrhythmias: - 250 mg IV load over 10 minutes, followed by 100 mg IV every 5 minutes as needed to a maximum of 1g

Administer at a rate of 25 mg/minute in elderly and patients with cardiac disease

CHILDREN

Status epilepticus:

• Loading dose - 18 mg/kg/dose IV
• Maintenance dose - 5-10 mg/kg/24 hours IV given every 12-24 hours

POTENTIAL HAZARDS OF PARENTERAL ADMINISTRATION

• cardiovascular collapse, CNS and respiratory depression, severe hypotension may occur with too rapid injection
• depression of cardiac conduction, ventricular fibrillation, heart block have been reported
• thrombophlebitis, pain with IV injection
• pain, tissue necrosis, and inflammation at IM injection site

IMPORTANT IMPLICATIONS

• signs of toxicity include:  drowsiness, nystagmus, ataxia, vertigo
• therapeutic plasma levels - 40-80 umol/L (10-20 mcg/mL)
• monitoring of serum levels is recommended: 2-4 hours after an IV loading dose; steady state trough levels (time to reach steady state) varies from 8-60 days
• dosage should not be increased at greater than 50-100 mg increments
• monitor infusion solutions for any precipitate formation
• discontinue if skin rash occurs

Rev. Nov 2007