Phenytoin

Therapeutic action

• Anticonvulsant

Indications

• Epilepsy, except absence seizure (petit mal)

Forms and strengths

• 100 mg tablet

Dosage

• Child 1 month to < 12 years: initially 1.5 to 2.5 mg/kg 2 times daily. According to response, increase up to 2 to 4 mg/kg 2 times daily (max. 7.5 mg/kg 2 times daily or 300 mg daily).
• Child 12 years and over: initially 75 to 150 mg 2 times daily. According to response, increase up to 150 to 200 mg 2 times daily (max. 300 mg 2 times daily).
• Adult: initially 75 to150 mg 2 times daily. According to response, increase up to 200 to 500 mg daily (max. 600 mg daily).

Duration

• According to clinical response

Contra-indications, adverse effects, precautions

• Do not administer in case of hypersensitivity to phenytoin. 
• May cause:
  • gastro-intestinal disturbances: gingival hypertrophy, nausea, vomiting;
  • blood disorders: monitor blood counts if possible and administer folic acid in case of prolonged use;
  • neurological disorders: dizziness, visual disturbances, mental confusion; 
  • allergic reactions: cutaneous eruption,fever, adenopathy.
• Do not stop treatment abruptly, decrease daily doses gradually.
• It is not recommended to combine phenytoin with oral contraceptives, sulphonamides or chloramphenicol. Combination with many other drugs must be closely monitored (diazepam, phenobarbital, digoxin, corticosteroids, etc.).
• Pregnancy: avoid
• Breast-feeding:avoid

Storage

– Below 25 °C

Never use phenytoin after expiry date (risk of under dosage).