Dilantin: Precision Seizure Control for Neurological Stability
| Product dosage: 100mg | |||
|---|---|---|---|
| Package (num) | Per pill | Price | Buy |
| 60 | $0.62 | $36.98 (0%) | 🛒 Add to cart |
| 90 | $0.54 | $55.47 $49.02 (12%) | 🛒 Add to cart |
| 120 | $0.49 | $73.96 $59.34 (20%) | 🛒 Add to cart |
| 180 | $0.45 | $110.94 $81.70 (26%) | 🛒 Add to cart |
| 270 | $0.42 | $166.41 $112.66 (32%) | 🛒 Add to cart |
| 360 | $0.41
Best per pill | $221.88 $147.06 (34%) | 🛒 Add to cart |
Synonyms
| |||
Dilantin (phenytoin) is a cornerstone antiepileptic medication with a well-established history in managing and preventing tonic-clonic and complex partial seizures. As a hydantoin derivative, it exerts its therapeutic effect by stabilizing neuronal membranes and reducing seizure spread through voltage-dependent blockade of sodium channels. This mechanism offers a targeted approach to controlling abnormal electrical activity in the brain, making it a first-line choice for many neurologists. Its availability in multiple formulations—including extended-release capsules, chewable tablets, and injectable solutions—provides flexibility in treatment regimens tailored to individual patient needs and clinical scenarios.
Features
- Active Ingredient: Phenytoin sodium
- Available Formulations: Extended-release capsules (30 mg, 100 mg), prompt-release chewable tablets (50 mg), oral suspension (125 mg/5 mL), and intravenous solution (50 mg/mL)
- Mechanism of Action: Voltage-gated sodium channel blockade
- Therapeutic Class: Hydantoin anticonvulsant
- Bioavailability: Formulation-dependent; extended-release exhibits ~90% bioavailability
- Protein Binding: Extensive (90-95%), primarily to albumin
- Metabolism: Hepatic via CYP2C9 and CYP2C19 enzymes
- Elimination Half-Life: Dose-dependent; typically 7-42 hours (average 22 hours)
- Steady-State Achievement: 7-10 days with oral administration
Benefits
- Provides reliable suppression of seizure activity through targeted neuronal stabilization
- Reduces frequency and severity of tonic-clonic and complex partial seizures
- Offers flexible dosing formulations to accommodate various patient needs and preferences
- Maintains therapeutic efficacy with once-daily dosing in appropriate formulations (extended-release)
- Demonstrates well-characterized pharmacokinetics allowing for therapeutic drug monitoring
- Established long-term safety profile with decades of clinical use and documentation
Common use
Dilantin is primarily indicated for the control of generalized tonic-clonic seizures and complex partial (psychomotor, temporal lobe) seizures. It may also be used for prevention and treatment of seizures occurring during or following neurosurgery. Off-label applications include certain cardiac arrhythmias (particularly those associated with digitalis toxicity) and neuropathic pain syndromes, though evidence supporting these uses is less robust. The medication is not effective for absence (petit mal) seizures and may potentially exacerbate them.
Dosage and direction
Dosage must be individualized based on therapeutic response and serum level monitoring. For adults initiating therapy: 100 mg oral three times daily, with dosage adjustment every 7-10 days. Maintenance dosing typically ranges from 300-400 mg daily, though some patients may require up to 600 mg daily. Extended-release capsules may be administered once daily if the dosage is stable. Pediatric dosing: initially 5 mg/kg/day in 2-3 divided doses, maintenance 4-8 mg/kg/day. Intravenous administration is reserved for status epilepticus or when oral administration is not feasible, with loading doses of 10-15 mg/kg at a rate not exceeding 50 mg/minute. Regular monitoring of serum phenytoin levels is essential, with therapeutic range generally considered to be 10-20 mcg/mL.
Precautions
- Regular monitoring of serum phenytoin levels is mandatory due to nonlinear pharmacokinetics
- Perform periodic complete blood counts and liver function tests
- Use with caution in patients with hepatic impairment, hypoalbuminemia, or renal dysfunction
- May cause drowsiness, dizziness, or visual disturbances; caution patients about operating machinery
- Abrupt discontinuation may precipitate status epilepticus; taper gradually under medical supervision
- Pregnancy Category D: may cause fetal harm; benefits must outweigh risks in pregnant women
- May decrease bone mineral density with long-term use; consider calcium and vitamin D supplementation
Contraindications
- Hypersensitivity to phenytoin, other hydantoins, or any component of the formulation
- Patients with sinus bradycardia, sinoatrial block, second- or third-degree AV block, or Adams-Stokes syndrome
- Concurrent use with delavirdine due to potential loss of virologic response
- Hepatic impairment where metabolism may be significantly compromised
- Patients with a history of acute intermittent porphyria
Possible side effect
Common adverse reactions (≥10%): nystagmus, ataxia, slurred speech, decreased coordination, mental confusion, dizziness, insomnia, transient nervousness. Less frequent reactions (1-10%): gingival hyperplasia, nausea, vomiting, constipation, headache, rash, morbilliform eruptions. Serious reactions (<1%): Stevens-Johnson syndrome, toxic epidermal necrolysis, drug reaction with eosinophilia and systemic symptoms (DRESS), hepatitis, blood dyscrasias (agranulocytosis, thrombocytopenia), lupus erythematosus, lymphadenopathy. Chronic use may lead to peripheral neuropathy, osteomalacia, and coarsening of facial features.
Drug interaction
Dilantin demonstrates extensive drug interactions due to its metabolism via CYP enzymes and protein-binding characteristics. Significant interactions include:
- CYP2C9/CYP2C19 inducers (carbamazepine, rifampin) may decrease phenytoin levels
- CYP2C9/CYP2C19 inhibitors (amiodarone, fluconazole) may increase phenytoin levels
- Phenytoin may decrease effectiveness of oral contraceptives, warfarin, corticosteroids, and many psychotropic medications
- Highly protein-bound drugs (valproic acid, salicylates) may displace phenytoin, increasing free fraction
- Concurrent use with other CNS depressants may enhance sedative effects
- Antacids may decrease absorption; separate administration by 2-3 hours
Missed dose
If a dose is missed, it should be taken as soon as possible. However, if it is almost time for the next dose, skip the missed dose and resume the regular dosing schedule. Do not double the dose to make up for a missed dose. Patients should maintain a consistent dosing schedule and use pill organizers or reminders if forgetfulness is a recurring issue. Extended-release formulations provide some forgiveness in timing due to their prolonged absorption characteristics.
Overdose
Phenytoin overdose manifests primarily as cerebellar and vestibular effects. Symptoms include nystagmus, ataxia, dysarthria, tremor, hyperreflexia, lethargy, and eventually coma. Cardiovascular effects may include hypotension and bradycardia. Management is supportive with careful monitoring of vital signs and neurological status. Gastric lavage may be considered if ingestion was recent. Multiple-dose activated charcoal may enhance elimination due to enterophepatic recirculation. Hemodialysis is not effective due to high protein binding. Serum levels >30 mcg/mL typically produce toxic effects, with levels >40 mcg/mL potentially life-threatening.
Storage
Store at controlled room temperature (20-25°C or 68-77°F). Protect from light and moisture. Keep the container tightly closed. Do not freeze the oral suspension. Injectable solution should be stored in original container and protected from light. Keep all medications out of reach of children and pets. Do not use beyond the expiration date printed on the packaging. Do not transfer capsules or tablets to other containers that do not provide equivalent protection from light and moisture.
Disclaimer
This information is for educational purposes only and does not constitute medical advice. Individual response to medication may vary. Always consult with a qualified healthcare professional before starting, stopping, or changing any medication regimen. The prescribing physician should be aware of the patient’s complete medical history and concurrent medications. Regular monitoring is essential for safe and effective use. Never share medication with others, even if they have similar symptoms.
Reviews
“Dilantin has been instrumental in controlling my complex partial seizures for over 15 years. While the gingival hyperplasia requires diligent dental care, the seizure control has allowed me to maintain employment and drive safely. Therapeutic drug monitoring has been crucial for maintaining optimal levels.” - M.K., 42
“As a neurologist with 30 years of experience, I continue to find Dilantin valuable for certain patient populations. Its predictable pharmacokinetics and availability of IV formulation make it particularly useful in hospital settings. However, I carefully monitor for drug interactions and adverse effects, especially in elderly patients.” - Dr. R.S., Neurologist
“The transition to extended-release capsules significantly improved medication adherence for my son with epilepsy. The once-daily dosing is much more manageable than the previous three-times-daily regimen. We’ve maintained therapeutic levels with fewer fluctuations in symptoms.” - Parent of pediatric patient