Primidone
Primidone is an anticonvulsant medication primarily used to treat seizure disorders including focal (partial) seizures and generalized tonic-clonic seizures. It works by being converted in the body to phenobarbital and phenylethylmalonamide, which increase GABA-mediated inhibition in the brain, reducing neuronal excitability that leads to seizures.
Primidone is an antiepileptic drug used to control seizures by enhancing inhibitory neurotransmission in the brain.
Key facts at a glance
- ATC
- N03AA03
- RxNorm
- 8691
- Generic
- Primidone
- Class
- atc-n03
- Brands
- Mysoline
- Availability
- rx
- Lactation
- unknown
- Routes
- oral
- Forms
- tablet, suspension
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Primidone is used to treat focal (partial) seizures, generalized tonic-clonic seizures, and may also be prescribed for essential tremor when other treatments are inadequate.
Primidone is metabolized to phenobarbital and phenylethylmalonamide (PEMA), which act as GABA-A receptor agonists to enhance inhibitory GABAergic signaling and reduce excessive neuronal firing associated with seizures.
Common side effects include drowsiness, dizziness, and ataxia; blood cell counts should be monitored regularly; abrupt discontinuation may cause status epilepticus; may interact with many other medications including other anticonvulsants and anticoagulants.
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 25, 2026. · Read our editorial policy