📋 Indications & Clinical Dosage
*Adjunctive treatment of focal seizures with or without secondary generalization:*
ORAL OR BY IV INF: Adult & Children above 16 yrs: Initially 50 mg twice daily, INF to be administered over 15-60 minutes (for up to 5 days), then increased, if tolerated, in steps of 50 mg twice daily, adjusted according to response, dose to be increased in weekly intervals; maintenance 100 mg twice daily (max. per dose 200 mg twice daily).
ORAL OR BY IV INF: Loading dose to rapidly attain therapeutic plasma concentrations (under close medical supervision): Adult & Children above 16 yrs: 200 mg, INF to be administered over 15-60 minutes (for up to 5 days), followed by maintenance 100 mg twice daily, to be given 12 hours after initial dose, then increased, if tolerated, in steps of 50 mg twice daily (max. per dose 200 mg twice daily), adjusted according to response, dose to be increased in weekly intervals.
⛔ Contraindications
Second- or third-degree AV block.
⚠️ Precautions & Warnings
Risk of PR-interval prolongation including con-duction problems, severe cardiac disease, and concomitant use of drugs that prolong PR interval, elderly.
🔄 Drug Interactions
Drugs associated with PR prolongation, class I antiarrhythmics, rifampicin, St. Johns wart, phenytoin, phenobarbital, fluconazole, itraconazole, ketoconazole,
ritonavir, clarithromycin
⚠️ Adverse Reactions / Side Effects
Aggression, agitation, headache, depression, dizziness, drowsiness, fatigue, blurred vision, cognitive disorder, constipation, flatulence, impaired coordination, nausea, nystagmus, pruritus, tremor, vomiting, agranulocytosis, atrial fibrillation, atrial flutter, AV block, bradycardia, confusion, dry mouth, dysarthria, dyspepsia, euphoria, hypoesthesia, irritability, muscle spasm, PR-interval prolongation, psychosis, rash, suicidal ideation, tinnitus. Rare Multi-organ hypersensitivity reaction
🤰 Pregnancy & Lactation Safety
Pregnancy Risk:
Avoid unless the potential benefit outweighs the risk.
Lactation / Breastfeeding:
Contraindicated, avoid
📚 Official Regulatory & Clinical References
- Drug Regulatory Authority of Pakistan (DRAP): Drug Registration, S.R.O. Price Gazettes & National Essential Medicines List (NEML).
- World Health Organization (WHO): Collaborating Centre for Drug Statistics Methodology (ATC/DDD Index).
- Formulary Standards: British National Formulary (BNF) & Pakistan National Formulary (PNF) guidelines.