Extended Phenytoin Sodium
(Phenytoin Sodium)Extended Phenytoin Sodium Prescribing Information
Extended phenytoin sodium capsules are indicated for the treatment of tonic-clonic (grand mal) and psychomotor (temporal lobe) seizures and prevention and treatment of seizures occurring during or following neurosurgery.
Adult starting dose in patients who have received no previous treatment is one 100 mg extended phenytoin sodium capsule three times a day, with dose adjustments as necessary. For most adults, the satisfactory maintenance dose will be one capsule three to four times a day. An increase, up to two capsules three times a day may be made, if necessary.
Adult once-a-day dose: If seizure control is established with divided doses of three 100 mg extended phenytoin sodium capsules daily, once-a-day dosage with 300 mg extended phenytoin sodium capsules may be considered.
Adult loading dose: reserved for patients in a clinic or hospital setting who require rapid steady-state serum levels and where intravenous administration is not desired. Refer to full prescribing information.
Pediatric starting dose is 5 mg/kg/day in two to three equally divided doses, with dosage adjustments as necessary, up to a maximum of 300 mg daily. Maintenance dosage is 4 to 8 mg/kg/day.
Serum blood level determinations may be necessary for optimal dosage adjustments—the clinically effective serum total concentration is 10 to 20 mcg/mL (unbound phenytoin concentration is 1 to 2 mcg/mL).
Extended phenytoin sodium capsules, USP are available as:
- 100 mg:white opaque/light lavender opaque, hard gelatin capsules imprinted with “IP 212” on both cap and body.
Phenytoin is contraindicated in patients with:
- A history of hypersensitivity to phenytoin, its inactive ingredients, or other hydantoins [see Warnings and Precautions (5.5)]. Reactions have included angioedema.
- A history of prior acute hepatotoxicity attributable to phenytoin [see Warnings and Precautions (5.8)].
- Co-administration with delavirdine because of the potential for loss of virologic response and possible resistance to delavirdine or to the class of non-nucleoside reverse transcriptase inhibitors.
Phenytoin sodium and other hydantoins are contraindicated in patients who have experienced phenytoin hypersensitivity
The following serious adverse reactions are described elsewhere in the labeling:
Withdrawal Precipitated Seizure, Status Epilepticus
[see Warnings and Precautions (5.1)]Suicidal Behavior and Ideation
[see Warnings and Precautions (5.2)]Serious Dermatologic Reactions
[see Warnings and Precautions (5.3)]Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)/Multiorgan Hypersensitivity
[see Warnings and Precautions (5.4)]
- Hypersensitivity [see Warnings and Precautions (5.5)]
- Cardiac Effects [see Warnings and Precautions (5.6)]
- Angioedema [see Warnings and Precautions (5.7)]
- Hepatic Injury [see Warnings and Precautions (5.8)]
- Hematopoietic Complications [see Warnings and Precautions (5.9)]
- Effects on Vitamin D and Bone [see Warnings and Precautions (5.10)]
- Exacerbation of Porphyria [see Warnings and Precautions (5.12)]
- Teratogenicity and Other Harm to the Newborn [see Warnings and Precautions (5.13)]
- Hyperglycemia [see Warnings and Precautions (5.14)]
The following adverse reactions associated with the use of phenytoin were identified in clinical studies or postmarketing reports. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
There have also been reports of coarsening of facial features, systemic lupus erythematosus, periarteritis nodosa, and immunoglobulin abnormalities.
A predominantly sensory peripheral polyneuropathy has been observed in patients receiving long-term phenytoin therapy.