✅ Active Ingredient Overview Table:

🔬 Active Ingredient (Generic Name):	Phenytoin
💊 Indication:	Epilepsy (Generalized and Partial Seizures), Status Epilepticus Prevention
🇺🇸 US Brand:	Dilantin
🏭 Manufacturer:	Abbott India Pvt. Ltd. (Founded: 1944)
📦 Packaging:	120 Tablets per Bottle
🧪 Strength:	100 mg
🚚 Delivery Time:	6–15 days

🌿 What is Phenytoin 100 mg (Eptoin)?

Eptoin contains Phenytoin, a classic anticonvulsant that stabilizes neuronal membranes by modulating voltage-gated sodium channels, thus reducing seizure activity. It is indicated for primary generalized tonic-clonic and complex partial seizures, as well as for prophylaxis against seizure recurrence following neurosurgery or head trauma.

Phenytoin displays nonlinear kinetics; the 100 mg tablet provides flexibility in dosage titration to achieve optimal plasma levels (10–20 µg/mL). Therapeutic monitoring is essential to balance efficacy and toxicity, with steady-state typically reached after 7–10 days.

Refer to the FDA label for Dilantin, the Drugs.com monograph, the NHS Medicines A–Z entry, and the WHO Essential Medicines List for detailed prescribing information.

🧬 Pharmacology & Mechanism of Action

Attribute	Detail
Chemical Formula	C15H12N2O
Molecular Weight	252.27 g/mol
Bioavailability	~90% (oral)
Metabolism	Hepatic (CYP2C9, CYP2C19)
Half-Life	~24 hours (varies with dose)

Phenytoin reduces sustained high-frequency firing of action potentials without affecting resting membrane potential.

💡 Indications & Dosing

Condition	Dose & Administration
Generalized Tonic-Clonic Seizures & Partial Seizures	Initial: 100 mg three times daily; titrate by 100 mg/day until seizure control or plasma levels reached
Status Epilepticus Prophylaxis	300–400 mg single dose pre- or post-operatively, as directed by neurologist

Administer with food to reduce GI upset. Avoid abrupt discontinuation to prevent rebound seizures.

⚠️ Warnings & Side Effects

Common:

Gingival hyperplasia
Hirsutism
Dizziness, ataxia

Serious:

Severe dermatologic reactions (SJS/TEN) in HLA-B*1502 carriers
Blood dyscrasias (agranulocytosis)
Hepatotoxicity

Monitor CBC, LFTs, and plasma levels. Screen at-risk ethnicities for HLA-B*1502. Counsel on oral hygiene to mitigate gum effects.

🏥 Storage Instructions

Store Eptoin 100 mg at 20–25°C in a cool, dry place. Keep the bottle tightly closed and protected from light.

🌐 Availability & Purchasing

USA: Prescription-only (Dilantin); brand and generics widely available.
UK & EU: Prescription required; generic phenytoin available.
Australia: Prescription and TGA approval required.

Importing from India may lower costs; ensure regulatory compliance and maintain valid prescription.

🔗 Related Antiepileptic Drugs

Zeptol 200 mg – Carbamazepine.
Lamotrigine 50 mg – Mood stabilizer AED.

🎥 Educational Video on Phenytoin Therapy

👨‍⚕️ Expert Insight: Dr. Neeta Sharma, Neurologist

“Phenytoin remains a cornerstone drug for seizure control, but its narrow therapeutic window and nonlinear kinetics necessitate careful monitoring of levels and side effects.”