Toggle menu
Toggle preferences menu
Toggle personal menu
Not logged in
Your IP address will be publicly visible if you make any edits.

Fosphenytoin

Checked
From Pharmacopedia
Anticonvulsant
Fosphenytoin
Cerebyx

Experience

👥 No personal reports yet
No clinical reports yet

Log in to add your own experience.

Problems

No problems yet. Be the first to suggest one.

+ Add a problem

Titration strategies

No titration strategies yet. Be the first to suggest one.

+ Add a titration strategy

Effects

No effects listed yet. Be the first to suggest one.

+ Add an effect

Interactions

Pharmacogenomic + mechanism interactions10 edges
Pharmacogenomic guideline recommendationsCPIC and Dutch Pharmacogenetics Working Group clinical guidelines
Phenotype:CYP2C9 normal metabolizer avoid CPIC A 90 / 100
CPIC rec 8094799 [Strong]: If patient is phenytoin-naive, do not use phenytoin/fosphenytoin. Avoid carbamazepine and oxcarbazepine. CPIC pair-level A (CYP2C9, HLA-B and Phenytoin) [PMID 25099164, 32779747] FDA labeling (Warnings and Precautions, Use in Specific Populations, Clinical Pharmacology)
Variant:hla-b 1502 pos contraindication CPIC A 90 / 100
CPIC rec 8094799 [Strong]: If patient is phenytoin-naive, do not use phenytoin/fosphenytoin. Avoid carbamazepine and oxcarbazepine. CPIC pair-level A (CYP2C9, HLA-B and Phenytoin) [PMID 25099164, 32779747]
CPIC rec 8094800 [Strong]: If patient is phenytoin-naive, do not use phenytoin/fosphenytoin. Avoid carbamazepine and oxcarbazepine. CPIC pair-level A (CYP2C9, HLA-B and Phenytoin) [PMID 25099164, 32779747] FDA labeling (Warnings and Precautions, Use in Specific Populations, Clinical Pharmacology)
Phenotype:CYP2C9 poor metabolizer avoid CPIC A 90 / 100
CPIC rec 8094802 [Strong]: If patient is phenytoin-naive, do not use phenytoin/fosphenytoin. Avoid carbamazepine and oxcarbazepine. CPIC pair-level A (CYP2C9, HLA-B and Phenytoin) [PMID 25099164, 32779747] FDA labeling (Warnings and Precautions, Use in Specific Populations, Clinical Pharmacology)
Phenotype:CYP2C9 poor metabolizer monitor CPIC A 70 / 100
CPIC rec 8094796 [Strong]: For first dose, use typical initial or loading dose. For subsequent doses use approximately 50% less than typical maintenance dose. Subsequent doses should be adjusted according to therapeutic drug monitoring, response, and side effects. An HLA-B*15:02 negative test does not eliminate the risk of phenytoin-induced SJS/TEN, and patients should be carefully monitored according to a usual standard. CPIC pair-level A (CYP2C9, HLA-B and Phenytoin) [PMID 25099164, 32779747]
Phenotype:CYP2C9 normal metabolizer normal dose CPIC A 60 / 100
CPIC rec 8094793 [Strong]: No adjustments needed from typical dosing strategies. Subsequent doses should be adjusted according to therapeutic drug monitoring, response, and side effects. An HLA-B*15:02 negative test does not eliminate the risk of phenytoin-induced SJS/TEN and patients should be carefully monitored according to a usual standard. CPIC pair-level A (CYP2C9, HLA-B and Phenytoin) [PMID 25099164, 32779747]
Phenotype:CYP2C9 intermediate metabolizer monitor CPIC A 45 / 100
CPIC rec 8094795 [Moderate]: For first dose, use typical initial or loading dose. For subsequent doses, use approximately 25% less than typical maintenance dose. Subsequent doses should be adjusted according to therapeutic drug monitoring, response and side effects. An HLA-B*15:02 negative test does not eliminate the risk of phenytoin-induced SJS/TEN, and patients should be carefully monitored according to a usual standard. CPIC pair-level A (CYP2C9, HLA-B and Phenytoin) [PMID 25099164, 32779747]
Phenotype:CYP2C9 intermediate metabolizer normal dose CPIC A 35 / 100
CPIC rec 8094794 [Moderate]: No adjustments needed from typical dosing strategies. Subsequent doses should be adjusted according to therapeutic drug monitoring, response and side effects. An HLA-B*15:02 negative test does not eliminate the risk of phenytoin-induced SJS/TEN and patients should be carefully monitored according to a usual standard. CPIC pair-level A (CYP2C9, HLA-B and Phenytoin) [PMID 25099164, 32779747]
Phenotype:CYP2C9 normal metabolizer monitor CPIC A 20 / 100
CPIC rec 8094819 [Optional]: If the patient has previously used phenytoin continuously for longer than three months without incidence of cutaneous adverse reactions, cautiously consider use of phenytoin in the future. The latency period for drug-induced SJS/TEN is short with continuous dosing and adherence to therapy (4-28 days), and cases usually occur within three months of dosing. CPIC pair-level A (CYP2C9, HLA-B and Phenytoin) [PMID 25099164, 32779747]
Variant:hla-b 1502 pos risk hypersensitivity CPIC A 20 / 100
CPIC rec 8094819 [Optional]: If the patient has previously used phenytoin continuously for longer than three months without incidence of cutaneous adverse reactions, cautiously consider use of phenytoin in the future. The latency period for drug-induced SJS/TEN is short with continuous dosing and adherence to therapy (4-28 days), and cases usually occur within three months of dosing. CPIC pair-level A (CYP2C9, HLA-B and Phenytoin) [PMID 25099164, 32779747]

Patient experience

No patient-experience reports yet.

Relevant anecdote

No anecdotes yet. Share a relevant one.

+ Add an anecdote

Relevant Literature

No literature entries yet.

Log in to submit relevant literature.

Summary
Classes
Anticonvulsant
Common uses
Pharmacy
Pharmacology
Purported mechanism
Prodrug of phenytoin; sodium channel blocker