About primidone
Antiseizure barbiturate
Used for
- Treats certain seizure disorders
- Sometimes used for essential tremor
Usual adult dose
Epilepsy: often starts at 100–125 mg at bedtime, increasing gradually; maintenance commonly 250 mg three or four times daily. Essential tremor: often starts at 25–50 mg daily, increasing gradually.
Usual dose in children
Epilepsy: usually starts around 50 mg at bedtime, increasing gradually; maintenance is individualized by weight and seizure control.
Common side effects
- Sleepiness, dizziness, or unsteadiness
- Nausea or loss of appetite
- Double vision or poor coordination
- Rarely, serious rash or blood disorders
Important warnings
- Do not stop suddenly; seizures may worsen.
- Can impair alertness; avoid driving until effects are known.
- Use caution with breathing problems, liver disease, or porphyria.
- Seek urgent care for severe rash, unusual bruising, or suicidal thoughts.
Pregnancy
May harm an unborn baby and increase birth-defect risk. Seizure control and pregnancy risks require specialist review.
Breastfeeding
Primidone and its active metabolite enter breast milk and may cause infant sleepiness or poor feeding; monitor closely with clinical guidance.
Interactions
- Alcohol, opioids, and sedatives can increase drowsiness and breathing suppression.
- May reduce effectiveness of hormonal contraceptives and some other medicines.
- Valproate can increase primidone levels; primidone may lower valproate levels.
- May interact with blood thinners and other antiseizure medicines.
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 It may be incomplete or out of date.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.