MedPath

Phenytoin

Generic Name
Phenytoin
Brand Names
Dilantin, Phenytek
Drug Type
Small Molecule
Chemical Formula
C15H12N2O2
CAS Number
57-41-0
Unique Ingredient Identifier
6158TKW0C5

Overview

Phenytoin is classified as a hydantoin derivative and despite its narrow therapeutic index, it is one of the most commonly used anticonvulsants. Since it's introduction about 80 years ago, phenytoin has not only been established as an effective anti-epileptic, but has also been investigated for several other indications such as bipolar disorder, retina protection, and wound healing. Clinicians are advised to initiate therapeutic drug monitoring in patients who require phenytoin since even small deviations from the recommended therapeutic range can lead to suboptimal treatment, or adverse effects. Both parenteral and oral formulations of phenytoin are available on the market.

Background

Phenytoin is classified as a hydantoin derivative and despite its narrow therapeutic index, it is one of the most commonly used anticonvulsants. Since it's introduction about 80 years ago, phenytoin has not only been established as an effective anti-epileptic, but has also been investigated for several other indications such as bipolar disorder, retina protection, and wound healing. Clinicians are advised to initiate therapeutic drug monitoring in patients who require phenytoin since even small deviations from the recommended therapeutic range can lead to suboptimal treatment, or adverse effects. Both parenteral and oral formulations of phenytoin are available on the market.

Indication

Phenytoin is indicated to treat grand mal seizures, complex partial seizures, and to prevent and treat seizures during or following neurosurgery. Injectable phenytoin and Fosphenytoin, which is the phosphate ester prodrug formulation of phenytoin, are indicated to treat tonic-clonic status epilepticus, and for the prevention and treatment of seizures occurring during neurosurgery.

Associated Conditions

  • Complex Partial Seizure Disorder
  • Generalized Tonic-Clonic Seizures
  • Grand Mal Status Epilepticus
  • Jacksonian epilepsy
  • Partial-Onset Seizures
  • Petit Mal Epilepsy
  • Seizure Disorder, Post Traumatic
  • Seizures
  • Status; Epilepticus, Tonic-clonic
  • Temporal Lobe Epilepsy (TLE)
  • Convulsive disorders

Clinical Trials

Title
Posted
Study ID
Phase
Status
Sponsor
2025/04/09
Phase 1
Recruiting
2025/04/02
Phase 1
Recruiting
2025/04/01
Phase 1
Completed
2024/12/06
Phase 1
Completed
2024/10/09
Phase 1
Completed
2024/08/07
Phase 1
Completed
2024/06/20
Phase 1
Completed
2024/04/23
Phase 1
Recruiting
2024/03/15
Not Applicable
Completed
Aalborg University
2023/10/04
Not Applicable
Completed

FDA Drug Approvals

Approved Product
Manufacturer
NDC Code
Route
Strength
Effective Date
REMEDYREPACK INC.
70518-0841
ORAL
50 mg in 1 1
2/13/2024
Aurobindo Pharma Limited
65862-692
ORAL
100 mg in 1 1
9/21/2023
Taro Pharmaceuticals U.S.A., Inc
51672-4146
ORAL
50 mg in 1 1
6/28/2022
Golden State Medical Supply, Inc.
51407-982
ORAL
100 mg in 1 1
5/27/2025
REMEDYREPACK INC.
70518-1776
ORAL
100 mg in 1 1
2/22/2024
Parke-Davis Div of Pfizer Inc
0071-0007
ORAL
50 mg in 1 1
3/21/2022
Hikma Pharmaceuticals USA Inc.
0641-0493
INTRAMUSCULAR, INTRAVENOUS
50 mg in 1 mL
1/18/2024
Major Pharmaceuticals
0904-6187
ORAL
100 mg in 1 1
4/1/2024
Aphena Pharma Solutions - Tennessee, LLC
71610-479
ORAL
100 mg in 1 1
11/12/2020
American Health Packaging
60687-275
ORAL
125 mg in 5 mL
10/31/2022

EMA Drug Approvals

Approved Product
Authorization Holder
Status
Issued Date
No EMA approvals found for this drug.

HSA Drug Approvals

Approved Product
Manufacturer
Approval Number
Dosage Form
Strength
Approval Date
DILANTIN CAPSULE 100 mg
SIN09208P
CAPSULE
100 mg
2/25/1997
DBL PHENYTOIN INJECTION BP 50 mg/ml
SIN08183P
INJECTION
50 mg/ml
5/22/1995
Dilantin 125® (Phenytoin Oral Suspension, USP) 125mg/5ml
SIN13114P
SUSPENSION
125.00mg/5ml
6/6/2005
DILANTIN CAPSULE 30 mg
SIN06056P
CAPSULE
30 mg
5/22/1991
PHARMANIAGA PHENYTOIN SODIUM SOLUTION FOR INJECTION 250MG/5ML
SIN16560P
INJECTION, SOLUTION
250mg/5mL
8/2/2022

NMPA Drug Approvals

Approved Product
Company
Approval Number
Drug Type
Dosage Form
Approval Date
Phenytoin Sodium Tablets
国药准字H44020161
化学药品
片剂
4/3/2020
Phenytoin Sodium Tablets
国药准字H23022476
化学药品
片剂(素片)
7/27/2020
Phenytoin Sodium Tablets
国药准字H51021834
化学药品
片剂(薄膜衣)
4/24/2020
Phenytoin Sodium Tablets
国药准字H53021426
化学药品
片剂
7/29/2020
Phenytoin Sodium Tablets
国药准字H32022551
化学药品
片剂
6/23/2020
Phenytoin Sodium Tablets
国药准字H22023362
化学药品
片剂
4/10/2020
Phenytoin Sodium Tablets
国药准字H41020002
化学药品
片剂
6/24/2020
Phenytoin Sodium Tablets
国药准字H23022003
化学药品
片剂
7/8/2020
Phenytoin Sodium Tablets
国药准字H13021694
化学药品
片剂
6/1/2020
Phenytoin Sodium Tablets
国药准字H14020187
化学药品
片剂
8/17/2020

PPB Drug Approvals

Approved Product
Registration No.
Company
Licence No.
Strength
Registration Date
No PPB approvals found for this drug.
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