TabletsClinical Overview
Phenytoin is a classic hydantoin antiepileptic on the WHO Model List of Essential Medicines. It voltage- and use-dependently promotes sodium channel inactivation, stabilizing neuronal membranes and limiting the spread of seizure activity from epileptic foci. Exhibits non-linear (Michaelis-Menten) saturation pharmacokinetics, where small dose increases can produce disproportionate, toxic rises in plasma concentrations. Indicated for tonic-clonic (grand mal) seizures, focal seizures, and prevention/treatment of seizures following neurosurgery.
Active Pharmaceutical Ingredients
Verified Clinical References
Usage Guidelines
Take orally with water, at the same times each day, with or immediately after food to reduce gastric irritation. Do not alter dose or switch formulations without therapeutic drug monitoring (target serum range: 10-20 mcg/mL). Maintain meticulous oral hygiene.
General Administration Advice: Adhere strictly to the prescribed dosage, frequency, and treatment course. For oral medications, swallow with sufficient water. Never stop antibiotics, psychiatric medications, or antihypertensives abruptly without clinical direction.
Possible Side Effects
Common: Nystagmus, ataxia, slurred speech, dizziness, gingival hyperplasia (gum swelling), hirsutism, coarsening of facial features. Rare/Severe: Boxed warning: Cardiovascular collapse and arrhythmias with rapid IV injection; cerebellar atrophy (with chronic high levels), DRESS syndrome, Stevens-Johnson syndrome, megaloblastic anemia, and osteomalacia.
*Note: Individual physiological responses vary. While many patients experience few or no side effects, notify your treating physician if adverse reactions persist or if hypersensitivity (angioedema, skin rash, dyspnea) occurs.
Precautions & Warnings
Boxed warning for rapid parenteral administration (hypotension and arrhythmias). Saturation pharmacokinetics requires routine therapeutic drug monitoring. Potent inducer of CYP3A4, CYP2C9, and CYP2C19. Mandatory oral hygiene and flossing to prevent severe gingival overgrowth.
Schedule H (Prescription Required)
This medication is scheduled under statutory drug regulatory frameworks (CDSCO / Drugs & Cosmetics Rules). Dispensing requires a valid medical prescription from a registered medical practitioner. Self-medication or unsupervised dosage adjustment carries significant clinical risks.
Medical Disclaimer: Statutory Clinical Disclaimer: The information provided is for educational and price-transparency purposes only and does not constitute medical advice, clinical diagnosis, or treatment recommendations. Always consult a registered medical practitioner or qualified pharmacist before initiating, modifying, or substituting any medication regimen.
