Dosing & Uses
Dosage Forms & Strengths
injectable solution
-
Cerebyx, Sesquient, generic
- 100mg PE/2mL
- 500mg PE/10mL
Status Epilepticus
Cerebyx, Sesquient, generic
Indicated for treatment of generalized tonic-clonic status epilepticus
Loading dose: 15-20 mg PE/kg IV at a rate of 100-150 mg PE/min, not to exceed 150 mg PE/min
Owing to full antiepileptic effect of phenytoin is not immediate, other measures, including coadministration of an IV benzodiazepine, may be necessary for the control of status epilepticus
If seizures continues after administration, consider using other anticonvulsants and other appropriate measures
If IV access is unavailable, loading doses have been given by IM route
Nonemergent Seizures
Cerebyx, Sesquient, generic
Indicated for prevention and treatment of seizures occurring during neurosurgery
Also, indicated for short-term substitution for oral phenytoin; only when oral phenytoin administration is not possible
Loading dose: 10-20 mg PE/kg IV; not to exceed 150 mg PE/min
Maintenance dose: 4-6 mg PE/kg/day IV in divided doses IV, not to exceed 150 mg PE/min
Individualize subsequent maintenance doses by monitoring serum concentrations to achieve a target therapeutic concentration
Owing to risks of cardiac and local toxicity associated with IV administration, oral phenytoin should be used whenever possible
Dosage Modifications
Renal or renal impairment
- Patients with renal or hepatic disease, or in those with hypoalbuminemia may have an increase amount of unbound phenytoin (active metabolite); monitor phenytoin serum levels based on the unbound fraction
- After IV administration to patients with renal and/or hepatic disease, or hypoalbuminemia, fosphenytoin clearance to phenytoin may be increased without a similar increase in phenytoin clearance; may potentiate the frequency and severity of adverse events
Dosing Considerations
Use caution when administering owing to the risk of dosing errors
Phenytoin sodium equivalents (PE)
- Express dose, concentration, and infusion rate of fosphenytoin as phenytoin sodium equivalents (PE) when prescribing
- No need to perform molecular weight-based adjustments when converting between fosphenytoin and phenytoin sodium doses
Concentration of 50 mg PE/mL
- Do not confuse the concentration of fosphenytoin with the total amount of drug in the vial
- Errors, including fatal overdoses, have occurred when vial concentration (50 mg PE/mL) was misinterpreted to mean that the total content of the vial was 50 mg PE
- These errors have resulted in 2-10 fold overdoses since each of the vials actually contains a total of 100 mg PE (2-mL vial) or 500 mg PE (10-mL vial)
- Ensure appropriate volume is withdrawn from vial when preparing dose
Monitoring parameters
- Continually monitor electrocardiogram, blood pressure, and respiratory function
- Observe patient throughout period where maximal serum phenytoin concentrations occur (~10-20 min after infusion ended)
Dosage Forms & Strengths
injectable solution
-
Cerebyx, Sesquient, generic
- 100mg PE/2mL
- 500mg PE/10mL
Status Epilepticus
Cerebyx, generic
Indicated for treatment of generalized tonic-clonic status epilepticus
Owing to full antiepileptic effect of phenytoin is not immediate, other measures, including coadministration of an IV benzodiazepine, may be necessary for the control of status epilepticus
If seizures continues after administration, consider using other anticonvulsants and other appropriate measures
If IV access is unavailable, loading doses have been given by IM route
Birth to <17 years
≥17 years
Nonemergent Seizures
Cerebyx: Indicated for prevention and treatment of seizures occurring during neurosurgery
Cerebyx, Sesquient: Also, indicated for short-term substitution for oral phenytoin; only when oral phenytoin administration is not possible
Individualize subsequent maintenance doses by monitoring serum concentrations to achieve a target therapeutic concentration
Owing to risks of cardiac and local toxicity associated with IV administration, oral phenytoin should be used whenever possible
Birth to <17 years (Cerebyx, generic)
- Loading dose: 10-15 mg PE/kg IV; 1-2 PE/kg/min, or 150 mg PE/min, whichever is slower
-
Maintenance dose
- 2-4 mg PE/kg/day IV in q12hr divided doses initially, THEN
- 4-8 mg PE/kg/day IV in q12hr divided doses
- At a rate of 1-2 mg PE/kg/min (or 100 mg PE/min, whichever is slower)
≥17 years (Cerebyx)
- Loading dose: 10-15 mg PE/kg IV; not to exceed 150 mg PE/min
- Maintenance dose: 4-6 mg PE/kg/day IV in divided doses, not to exceed 150 mg PE/min
2-17 years (Sesquient)
- <2 years: Safety and efficacy not established
-
>2 years
- Loading dose: 10-15 mg PE/kg IV; not to exceed 0.4 mg PE/kg/min
- 2-4 mg PE/kg IV in q12hr divided doses initially, THEN
- 4-8 PE/kg/day IV in q12hr divided doses
- Because of the betadex sulfobutyl ether sodium ingredient in Sesquient, do not exceed administration rate in pediatric patients of 0.4 mg PE/kg/min
Dosage Modifications
Renal or renal impairment
- Patients with renal or hepatic disease, or in those with hypoalbuminemia may have an increase amount of unbound phenytoin (active metabolite); monitor phenytoin serum levels based on the unbound fraction
- After IV administration to patients with renal and/or hepatic disease, or hypoalbuminemia, fosphenytoin clearance to phenytoin may be increased without a similar increase in phenytoin clearance; may potentiate the frequency and severity of adverse events
Dosing Considerations
Use caution when administering owing to the risk of dosing errors
Phenytoin sodium equivalents (PE)
- Express dose, concentration, and infusion rate of fosphenytoin should always be expressed as phenytoin sodium equivalents (PE) when prescribing
- No need to perform molecular weight-based adjustments when converting between fosphenytoin and phenytoin sodium doses
Concentration of 50 mg PE/mL
- Do not confuse the concentration of fosphenytoin with the total amount of drug in the vial
- Errors, including fatal overdoses, have occurred when vial concentration (50 mg PE/mL) was misinterpreted to mean that the total content of the vial was 50 mg PE
- These errors have resulted in 2-10 fold overdoses since each of the vials actually contains a total of 100 mg PE (2-mL vial) or 500 mg PE (10-mL vial)
- Ensure appropriate volume is withdrawn from vial when preparing dose
Monitoring parameters
- Continually monitor electrocardiogram, blood pressure, and respiratory function
- Observe patient throughout period where maximal serum phenytoin concentrations occur (~10-20 min after infusion ended)
- Usual therapeutic serum total phenytoin concentration 10-20 mcg/mL (unbound phenytoin concentration [1-2 mcg/mL])
- Recommended to not monitor until conversion to phenytoin is complete (~2 hr after end of IV infusion and ~4 hr after IM administration)
Interactions
Interaction Checker
No Results

Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor

Adverse Effects
>10%
Adults and children
- Body as a whole: Fever, injection-site reaction, infection, chills, face edema, injection-site pain
- Cardiovascular: Hypertension
- Digestive: Constipation
- Metabolic and nutritional: Hypokalemia
- Musculoskeletal: Myasthenia; Infrequent: myopathy, leg cramps, arthralgia, myalgia
- Nervous: Reflexes increased, speech disorder, dysarthria, intracranial hypertension, thinking abnormal, nervousness
- Respiratory: Pneumonia
- Skin and appendages: Rash
IV, adults
- Pruritus (49%)
- Nystagmus (44%)
- Dizziness (31%)
- Somnolence (20%)
- Ataxia (11%)
IV, children and adolescents
- Vomiting (21%)
- Nystagmus (18%)
IM
- Nystagmus (15%)
1-10%
Adults and children
- Body as a whole: Sepsis, injection-site inflammation, injection-site edema, injection-site hemorrhage, flu syndrome, malaise, generalized edema, shock, photosensitivity reaction, cachexia, cryptococcosis
- Endocrine: Diabetes insipidus
- Hematologic and lymphatic: Thrombocytopenia, anemia, leukocytosis, cyanosis, hypochromic anemia, leukopenia, lymphadenopathy, petechia
- Metabolic and nutritional: Hyperglycemia, hypophosphatemia, alkalosis, acidosis, dehydration, hyperkalemia, ketosis
- Musculoskeletal: Myopathy, leg cramps, arthralgia, myalgia
- Nervous: Confusion, twitching, Babinski sign positive, circumoral paresthesia, hemiplegia, hypotonia, convulsion, extrapyramidal syndrome, insomnia, meningitis, depersonalization, CNS depression, depression, hypokinesia, hyperkinesia, paralysis, psychosis, aphasia, emotional lability, coma, hyperesthesia, myoclonus, personality disorder, acute brain syndrome, encephalitis, subdural hematoma, encephalopathy, hostility, akathisia, amnesia, neurosis
- Skin and appendages: Maculopapular rash, urticaria, sweating, skin discoloration, contact dermatitis, pustular rash, skin nodule
- Special senses: Visual field defect, eye pain, conjunctivitis, photophobia, hyperacusis, mydriasis, parosmia, ear pain, taste loss
- Urogenital: Urinary retention, oliguria, dysuria, vaginitis, albuminuria, genital edema, kidney failure, polyuria, urethral pain, urinary incontinence, vaginal moniliasis
IV, adults
- Nausea (9%)
- Tinnitus (9%)
- Hypotension (8%)
- Stupor (8%)
- Vasodilatation (6%)
- Pelvic pain (4%)
- Tongue disorder (4%)
- Dry mouth (4%)
- Incoordination (4%)
- Paresthesia (4%)
- Extrapyramidal syndrome (4%)
- Tremor (3%)
- Agitation (3%)
- Diplopia (3%)
- Taste perversion (3%)
- Amblyopia (2%)
- Deafness (2%)
- Hypesthesia (2%)
- Dysarthria (2%)
- Vertigo (2%)
- Brain edema (2%)
- Vomiting (2%)
- Asthenia (2%)
- Back pain (2%)
- Headache (2%)
IV, children and adolescents
- Ataxia (10%)
- Fever (8%)
- Nervousness (7%)
- Pruritus (6%)
- Somnolence (6%)
- Hypotension (5%)
- Rash (5%)
IM
- Tremor (10%)
- Headache (9%)
- Asthenia (9%)
- Ataxia (8%)
- Incoordination (8%)
- Somnolence (7%)
- Dizziness (5%)
- Nausea (5%)
- Paresthesia (4%)
- Reflexes decreased (3%)
- Pruritus (3%)
- Vomiting (3%)
Postmarketing Reports
Body as a whole: Anaphylaxis, angioedema
Laboratory test abnormality: Decrease serum concentrations of T4; may also produce lower than normal values for dexamethasone or metyrapone tests; increase serum levels of gamma glutamyl transpeptidase
Nervous system disorders: Dyskinesia
Warnings
Black Box Warnings
Cardiovascular risk associated with rapid infusion rates
- Risk of hypotension and arrhythmias with infusion rates that exceed 150 mg/minute of phenytoin sodium equivalents (PE)
- Careful cardiac monitoring is needed during and after administering IV administration; these events have also been reported at or below 150 mg PE/minute
- Recommended doses should not be changed when substituting fosphenytoin for phenytoin or vice versa; they are not equivalent on mg to mg basis
- Reduce infusion rate or discontinuation may be needed
Contraindications
Hypersensitivity to or its inactive ingredients, or to phenytoin or other hydantoins
Sinus bradycardia, sinoatrial block, 2nd or 3rd degree AV block, Adams-Stokes syndrome
Prior history of acute hepatotoxicity attributable to fosphenytoin or phenytoin
Coadministration with delavirdine
Cautions
Do NOT give IM for status epilepticus initial dose
Renal, hepatic or other hypoalbuminemic disease: monitor unbound phenytoin concentration
Do not abruptly discontinue antiepileptic drugs because of the possibility of increased seizure frequency, including status epilepticus; in the event of an allergic or hypersensitivity reaction, rapid substitution of alternative therapy may be necessary
Associated with exacerbation of porphyria; exercise caution when fosphenytoin is used in patients with this disease
Hyperglycemia, resulting from phenytoin’s inhibitory effect on insulin release, reported; phenytoin may also raise serum glucose concentrations in diabetic patients
Do not discontinue antiepileptic drugs abruptly because of possibility of increased seizure frequency, including status epilepticus; reduce dose gradually when necessary; in the event of allergic or hypersensitivity reaction, rapid substitution of alternative therapy, not belonging to hydantoin chemical class is necessary
Cases of acute hepatotoxicity, including infrequent cases of acute hepatic failure, reported with phenytoin; discontinue and do not readminister if acute hepatotoxicity occurs
Hematopoietic complications (eg, thrombocytopenia, leukopenia, granulocytopenia, agranulocytosis, pancytopenia with or without bone marrow suppression), some fatal, have occasionally been reported; in cases of lymphadenopathy, follow-up observation for an extended period is indicated
Consider phosphate load (0.0037 mmol phosphate/mg PE fosphenytoin) when treating patients who require phosphate restriction, such as those with severe renal impairment
Safety/efficacy not evaluated for administration > 5 days
Consider alternatives to structurally similar drugs such as carboxamides (eg, carbamazepine), barbiturates, succinimides, and oxazolidinediones (eg, trimethadione) in patients who experienced phenytoin hypersensitivity
Angioedema reported with phenytoin and fosphenytoin; discontinue immediately if symptoms of angioedema (eg, facial, perioral, or upper airway swelling) occur
Severe burning, itching, and/or paresthesia were reported; IV fosphenytoin at doses of 20 mg PE/kg at 150 mg PE/min are expected to experience discomfort of some degree; occurrence and intensity of discomfort can be lessened by slowing or temporarily stopping the infusion
Local toxicity (Purple Glove Syndrome) that includes edema, discoloration, and pain distal to the site of injection has been reported following peripheral IV injection; may or may not be associated with extravasation; this syndrome may not develop for several days after injection
May cause fetal harm when administered to pregnant females
Small percentage of treated individuals have been shown to metabolize phenytoin slowly; slow metabolism may be caused by limited enzyme availability and lack of induction; if early signs of dose-related CNS toxicity develop, check serum levels immediately
Hyperglycemia, resulting from inhibitory effect of phenytoin on insulin release, has been reported; phenytoin may also raise serum glucose concentrations in diabetic patients
Serum levels of phenytoin (the active metabolite of fosphenytoin) sustained above therapeutic range may produce confusional states referred to as “delirium,” “psychosis,” or “encephalopathy,” or rarely, irreversible cerebellar dysfunction and/or cerebellar atrophy; at first sign of acute toxicity, check serum levels immediately; reduce dose if serum levels are excessive; discontinue therapy if symptoms persist
Cardiovascular risk associated with rapid infusion
- Rapid IV administration increases the risk of adverse cardiovascular reactions, including severe hypotension and cardiac arrhythmias (eg, bradycardia, heart block, QT prolongation, ventricular tachycardia, ventricular fibrillation); use oral phenytoin whenever possible
- Carefully monitor cardiac and respiratory function and after IV administration; consider reducing rate or discontinuing dose
Severe cutaneous reactions
- Can cause severe cutaneous adverse reactions (SCARs), which may be fatal
- Reported reactions include toxic epidermal necrolysis (TEN), Stevens-Johnson syndrome (SJS), acute generalized exanthematous pustulosis (AGEP), and Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)
- Onset is usually within 28 days, but can occur later
- Discontinue at the first sign of a rash, unless the rash is clearly not drug-related
- If signs or symptoms suggest a severe cutaneous adverse reaction, do not resume drug; consider alternant therapy
- Studies in patients of Chinese ancestry have found a strong association between risk of developing SJS/TEN and the presence of HLA-B*1502, an inherited allelic variant of the HLA B gene in patients taking carbamazepine
- Limited evidence suggests that HLA-B*1502 may also be a risk factor for the development of SJS/TEN in patients taking other antiepileptic drugs
DRESS
- DRESS, also known as multiorgan hypersensitivity, reported in patients taking antiepileptic drugs, including phenytoin and fosphenytoin
- Some of these events have been fatal or life-threatening
- DRESS typically, although not exclusively, presents with fever, rash, lymphadenopathy, and/or facial swelling, in association with other organ system involvement (eg, hepatitis, nephritis, hematological abnormalities, myocarditis, or myositis sometimes resembling an acute viral infection); eosinophilia is often present
- Early manifestations of hypersensitivity (eg, fever or lymphadenopathy) may be present even though rash is not evident
- If such signs or symptoms are present, evaluate patient immediately; discontinue drug if unable to confirm other etiology for the rash
Dosing errors
- Do not confuse amount of drug to be given in PE with concentration of drug in vial
- Medication errors associated with fosphenytoin have resulted in wrong dose being administer
Drug interaction overview
- CYP2C9 and CYP2C19 substrate; potent inducer of hepatic drug-metabolizing enzymes
- Extensively bound to human plasma proteins
- Addition or withdrawal of these agents in patients on phenytoin therapy may require an dosage adjustment of the phenytoin to achieve optimal clinical outcome
-
Drugs that may increase phenytoin concentration
- Antiepileptic drugs (ie, ethosuximide, felbamate, oxcarbazepine, methsuximide, topiramate)
- Azoles (ie, fluconazole, ketoconazole, itraconazole, miconazole, voriconazole)
- Antineoplastic agents (eg, capecitabine, fluorouracil)
- Antidepressants (ie, fluoxetine, fluvoxamine, sertraline)
- Gastric acid reducing agents (eg, H2 antagonists, omeprazole)
- Sulfonamides (eg, sulfamethizole, sulfaphenazole, sulfadiazine, sulfamethoxazole/trimethoprim)
- Acute alcohol intake, amiodarone, chloramphenicol, chlordiazepoxide, disulfiram, estrogen, fluvastatin, isoniazid, methylphenidate, phenothiazines, salicylates, ticlopidine, tolbutamide, trazodone, warfarin
- Drugs highly bound to albumin could increase the unbound fraction of fosphenytoin
-
Drug that may decrease phenytoin serum levels
- Antineoplastic agents, usually in combination (eg, bleomycin, carboplatin, cisplatin, methotrexate
- Antiviral agents (eg, fosamprenavir, nelfinavir, ritonavir)
- Antiepileptic drugs (eg, carbamazepine, vigabatrin)
- Chronic alcohol abuse, diazepam, diazoxide, folic acid, reserpine, rifampin, St. John wort, theophylline
- Drugs that may either increase or decrease phenytoin serum levels H5
- Antiepileptic drugs (eg, phenobarbital, valproate sodium, valproic acid)
-
Drugs that decrease efficacy by phenytoin
- Azoles (eg, fluconazole, ketoconazole, itraconazole, posaconazole, voriconazole)
- Antineoplastic agents (eg, irinotecan, paclitaxel, teniposide)
- Increased and decreased PT/INR responses have been reported when phenytoin is coadministered with warfarin
- Coadministration with NNRTIs may cause loss of virologic response and possible resistance to NNRTIs (eg, delavirdine)
- Cisatracurium, pancuronium, rocuronium and vecuronium: resistance to the neuromuscular blocking action of the nondepolarizing neuromuscular blocking agents has occurred in patients chronically administered phenytoin; closely monitor for more rapid recovery from neuromuscular blockade than expected, and infusion rate requirements may be higher
- Others: Corticosteroids, doxycycline, estrogens, furosemide, oral contraceptives, paroxetine, quinidine, rifampin, sertraline, theophylline, and vitamin D
-
Drugs whose level is decreased by phenytoin
- Antiepileptic drugs (eg, carbamazepine, felbamate, lamotrigine, topiramate, oxcarbazepine)
- Antilipidemic agents (eg, atorvastatin, fluvastatin, simvastatin)
- Antiviral agents (eg, efavirenz, lopinavir/ritonavir, indinavir, nelfinavir, ritonavir, saquinavir)
- Fosamprenavir: Phenytoin is coadministered with fosamprenavir alone may decrease the concentration of amprenavir (active metabolite); when phenytoin is coadministered with the combination of fosamprenavir and ritonavir may increase the concentration of amprenavir
- Calcium channel blockers (eg, nifedipine, nimodipine, nisoldipine, verapamil)
- Others: Albendazole (decreases active metabolite), chlorpropamide, clozapine, cyclosporine, digoxin, disopyramide, folic acid, methadone, mexiletine, praziquantel, quetiapine
-
Drug/laboratory test interactions
- Exercise caution when using immunoanalytical methods to measure serum phenytoin concentrations following administration
Pregnancy & Lactation
Pregnancy
Exposure of phenytoin may increase the risks for congenital malformations and other adverse developmental outcomes
Prenatal phenytoin exposure is associated with an increased incidence of major malformations, including orofacial clefts and cardiac defects
In addition, the fetal hydantoin syndrome, a pattern of abnormalities including dysmorphic skull and facial features, nail and digit hypoplasia, growth abnormalities (including microcephaly), and cognitive deficits has been reported among children born to epileptic women who took phenytoin alone or in combination with other antiepileptic drugs during pregnancy
There have been several reported cases of malignancies, including neuroblastoma, in children whose mothers received phenytoin during pregnancy
Pregnancy exposure registry
- Monitors pregnancy outcomes in women exposed to antiepileptic drugs during pregnancy
- Advised to pregnant females to enroll in the North American Antiepileptic Drug (NAAED) Pregnancy Registry by calling the toll free number 1-888-233-2334, and must be done by patients themselves
- Information on the registry can also be found at http://www.aedpregnancyregistry.org/
Animal data
- Administration to pregnant animals resulted in an increased incidence of fetal malformations and other manifestations of developmental toxicity (including embryofetal death, growth impairment, and behavioral abnormalities) in multiple species at clinically relevant doses
Clinical considerations
- An increase in seizure frequency may occur during pregnancy because of altered phenytoin pharmacokinetics
- Consider periodic measurement of serum phenytoin concentrations to provide the appropriate dosage adjustment; postpartum restoration of original dosage may be necessary
- A potentially life-threatening bleeding disorder related to decreased levels of vitamin K-dependent clotting factors may occur in newborns exposed to phenytoin in utero; may be prevented with vitamin K administration to mother before delivery and to neonate after birth
Lactation
It is not known whether fosphenytoin is secreted in human milk
Following administration of phenytoin, phenytoin is secreted in human milk
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
Converted to phenytoin after injection; stabilizes neuronal membranes and decrease seizure activity by increasing efflux or decreasin influx of sodium ions across cell membranes in the motor cortex during generation of nerve impulses
Absorption
Bioavailability (IM): Completely bioavailable
Peak plasma concentration
- IV: When administered by IV infusion, maximum plasma fosphenytoin concentrations are achieved at the end of the infusion
- IM: Following IM administration, plasma concentration are lower but more sustained than IV due to time required for absorption of fosphenytoin from the injection site
Peak plasma time
- IM: ~30 minutes postdose
Distribution
Protein bound: ~95-99% to human plasma proteins, primarily albumin
Vd: 4.3-10.8 L
Metabolism
Fosphenytoin is rapidly converted via hydrolysis to phenytoin; phenytoin is metabolized in the liver and forms metabolites.
Elimination
Half-life: ~ 15 min (conversion of fosphenytoin to phenytoin)
Excretion: Not in urine
Pharmacogenomics
Patients with HLA-B*1502 with are more likely to have a severe dermatologic reaction (eg, TEN, Stevens-Johnson syndrome) when taking phenytoin
This allele occurs almost exclusively in patients with ancestry across broad areas of Asia, including Han Chinese, Filipinos, Malaysians, South Asian Indians, and Thais
Maternal epoxide (EPHX1) genotypes 113*H and 139*R are associated with risk of fetal hydantoin syndrome among pregnant women taking phenytoin
Increased levels of the reactive epoxide metabolites by either inhibiting the detoxification of these metabolites by epoxide hydrolase or by increasing conversion to epoxide metabolites by inducing CYP3A4, 2C9, or 2C19
Genetic testing laboratories
- The following companies provide genetic testing for HLA variants
- Kashi Clinical Laboratories (www.kashilab.com)
- LabCorp (http://www.labcorp.com/)
- Specialty Laboratories (http://www.specialtylabs.com)
- Quest (http://www.questdialgnotics.com)
Administration
IV Incompatibilities
Y-site: fenoldopam, midazolam
IV Preparation
Dilute in D5W or NS to concentration of 1.5-25 mg PE/mL
IV Administration
Express all dosing in mg "phenytoin equivalents" (PE); 1 mg PE is equivalent to 1 mg phenytoin sodium
Do not confuse the concentration with the total amount of drug in the vial
IV infusion preferred route for emergent use and for pediatrics because of delayed absorption
Maximum IV infusion rate
- Adults (≥17 years): Not to exceed 150 mg PE/min
- Birth to <17 years: 2 mg PE/kg/min (or 100 mg PE/min, whichever is slower)
Monitor
- Continuous monitoring of ECG, BP, and respiratory function essential; observe patient throughout the period where maximal serum phenytoin concentrations occur, ~10-20 min after the end of infusions
- Phenytoin levels: Obtain 2 hr after IV or 4 hr after IM
Storage
Unused vials
- Cerebyx, generic: Refrigerate at 2-8ºC (36-46ºF); do not store at room temperature for more than 48 hr
- Sesquient: Store at room temperature 20-25ºC (68-77ºF); excursions permitted to 15-30ºC (59-86∫F)
- Vials that develop particulate matter should not be used
- After opening, discard any unused solution in vials
Diluted infusions
- Stable at 1, 8, and 20 mg PE/mL in normal saline or D5W at 25ºC (77ºF) for 30 days in glass container and at 4-20ºC (39-68ºF) for 30 days in PVC bag
Images
Patient Handout
Formulary
Adding plans allows you to compare formulary status to other drugs in the same class.
To view formulary information first create a list of plans. Your list will be saved and can be edited at any time.
Adding plans allows you to:
- View the formulary and any restrictions for each plan.
- Manage and view all your plans together – even plans in different states.
- Compare formulary status to other drugs in the same class.
- Access your plan list on any device – mobile or desktop.