About phenytoin sodium
Hydantoin anticonvulsant
Used for
- Treats and prevents certain epileptic seizures.
- Prevents seizures during or after some neurosurgical procedures.
Usual adult dose
Common starting dose is 100 mg three times daily; dosing is adjusted to blood levels and response.
Usual dose in children
Usually 5 mg/kg daily in two or three divided doses; adjusted to response and blood levels.
Common side effects
- Dizziness, drowsiness, and unsteadiness
- Gum overgrowth and increased body hair
- Nausea or vomiting
- Rash; rarely, severe skin reactions
Important warnings
- Do not stop suddenly; seizures may worsen.
- Seek urgent care for severe rash, facial swelling, or breathing difficulty.
- Long-term use can affect bones and vitamin D levels.
- Blood-level monitoring and regular dental care may be needed.
Pregnancy
May cause birth defects and affect vitamin K; treatment requires specialist review. Do not stop suddenly.
Breastfeeding
Usually compatible with breastfeeding, but monitor the infant for sleepiness, poor feeding, or rash.
Interactions
- Many medicines affect phenytoin levels, including antibiotics and antifungals.
- Phenytoin can reduce the effectiveness of hormonal contraceptives.
- Alcohol and some sedatives may increase dizziness or drowsiness.
- Antacids and tube feeding can reduce absorption.
AI-generated from general medical knowledge, not from this product's official leaflet. It may be incomplete or out of date. Not medical advice — ask a pharmacist or doctor before making any decision.