Phenytoin
Brand: Dilantin (US) / Eptoin (IN) / Dantoin (BD)
Anticonvulsant
Sodium channel blocker
Pharmacokinetics
| Half-life | 22 hours |
| Tmax | 4 h |
| Bioavailability | 90 % (approx) |
| Protein Binding | 90 % |
| Volume of Distribution | 0.7 L/kg (approx) |
| Clearance Route | hepatic |
| Active Metabolites | yes |
| Notes | Zero-order kinetics at higher levels; small dose change can cause big level change. |
⚠️ Safety & Warnings
Severity: Severe
Adverse Effects:
Ataxia, nystagmus, gingival hyperplasia, hirsutism, rash, neuropathy
Contraindications:
Known hypersensitivity, severe hepatic impairment
Precautions:
Requires drug level monitoring; many drug interactions; caution in elderly