💊 Phenytoin Tablet 300 mg
📌 1. Prescription / Indications:
Phenytoin 300 mg tablets are prescribed for:
- Management of generalized tonic-clonic seizures
- Focal (partial) seizures
- Prevention of seizures post-neurosurgery or head trauma
- Occasionally for digitalis-induced cardiac arrhythmias
It is often used as a once-daily dose for maintenance when 300 mg/day is needed.
📄 2. Description:
- Form: Oral tablet or extended-release capsule
- Strength: 300 mg phenytoin sodium
- Appearance: White to off-white, oval or oblong; sometimes marked “300”
- Route: Oral
- Dosing: Often given once daily; individualized per blood levels
🔬 3. Nature / Drug Class:
- Class: Hydantoin anticonvulsant
- Mechanism: Stabilizes neuronal membranes by blocking voltage-gated sodium channels, reducing repetitive firing
🌟 4. Advantages:
- Convenient once-daily dose for many adults
- Helps maintain stable blood levels
- Effective for long-term seizure control
- Available as extended-release (ER) capsules for sustained action
📦 5. Common Packaging:
| Packaging | Details |
|---|---|
| Blister Pack | 10 or 15 tablets per strip |
| Bottle | 30, 100, or 500 tablets |
| Hospital Bulk Pack | For institutional use |
🧊 6. Storage Conditions:
- Store at room temperature below 25°C
- Keep container tightly closed
- Protect from light and moisture
- Do not refrigerate or freeze
👩⚕️ 7. Patient Advice:
- Take with or after food to reduce stomach upset
- Take at the same time daily
- Do not crush/chew extended-release tablets
- Regular blood tests to monitor phenytoin levels are essential
- Be alert for side effects like:
- Gum overgrowth (gingival hyperplasia)
- Nausea, fatigue
- Blurred vision, ataxia (poor coordination)
- Skin rash or allergic reaction
- Maintain good oral hygiene
- Avoid alcohol and sudden discontinuation
- Inform your doctor if you are pregnant or planning pregnancy
🎯 8. Purpose / Use Cases:
| Condition | Use |
|---|---|
| Epilepsy | Tonic-clonic, focal seizures |
| Head injury / surgery | Seizure prophylaxis |
| Status epilepticus follow-up | After IV phenytoin loading |
| Arrhythmia (rare) | Digitalis-induced ventricular arrhythmias |
⚠️ 9. Precautions / Warnings:
- Narrow therapeutic index (monitor levels: 10–20 mcg/mL)
- May cause:
- Liver dysfunction
- Osteomalacia
- Megaloblastic anemia
- Hirsutism
- May interact with:
- Warfarin, oral contraceptives, steroids, and many antiepileptics
- Pregnancy Category D: Risk of fetal hydantoin syndrome