Europe — EMA
Mysoline (Primidone)
GNH USA supplies Mysoline (Primidone), a barbiturate for partial seizures, generalized tonic‑clonic seizures and essential tremor. Request a quote for supply.
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What is Primidone?
Primidone, the active ingredient in Mysoline, is a barbiturate presented as an oral dosage form for oral use. It is employed to control certain types of seizures and to reduce essential tremor in adult patients. GNH USA supplies Mysoline as a licensed, GDP‑compliant international pharmaceutical supplier serving hospitals, pharmacies and clinics worldwide.
What is Primidone used for?
Mysoline (Primidone) is an antiepileptic medication that modulates neuronal excitability in seizure‑related pathways. - Partial seizures: helps reduce the frequency and severity of focal onset seizures. - Generalized tonic‑clonic seizures: provides control of convulsive episodes across the brain. - Essential tremor: diminishes tremor amplitude in patients with this movement disorder.
What are the side effects of Primidone?
Mysoline may cause a range of adverse reactions, which vary in frequency and severity.
Common Side Effects: - Drowsiness: feeling unusually sleepy or fatigued. - Dizziness: light‑headed sensation, especially when standing quickly. - Nausea: mild stomach upset or queasiness. - Ataxia: unsteady gait or coordination problems. - Rash: mild skin irritation or redness.
Serious or Rare Side Effects: - Severe skin reactions: Stevens‑Johnson syndrome or toxic epidermal necrolysis. - Blood dyscrasias: agranulocytosis, aplastic anemia, or thrombocytopenia. - Hepatic dysfunction: jaundice, elevated liver enzymes. - Respiratory depression: markedly slowed breathing. - Suicidal thoughts: emergence of depressive or suicidal ideation.
What precautions apply to Primidone?
Before initiating Mysoline, clinicians should evaluate patient history and monitor specific parameters. - Monitor blood counts: perform regular complete blood count tests to detect hematologic abnormalities. - Assess liver function: check hepatic enzymes periodically, especially in patients with known liver disease. - Avoid abrupt discontinuation: taper the dose under medical supervision to prevent withdrawal seizures. - Pregnancy considerations: use only if potential benefit justifies potential risk to the fetus. - Caution in depression: monitor for mood changes or suicidal thoughts. - Store at ambient temperature: keep in the original container, protect from moisture and direct sunlight.
What does Primidone interact with?
Mysoline can affect, and be affected by, several concomitant medications.
Major Interactions (Avoid): - CYP3A4 inducers (e.g., carbamazepine, phenytoin): may reduce Primidone plasma levels, decreasing efficacy. - Warfarin: increased anticoagulant effect, raising bleeding risk. - Oral contraceptives: reduced hormonal efficacy, potentially leading to unintended pregnancy.
Moderate Interactions (Monitor Closely): - CNS depressants (e.g., benzodiazepines, opioids): additive sedation and respiratory depression. - Other antiepileptics (e.g., valproate, levetiracetam): may require dose adjustments. - Alcohol: enhances sedative effects and impairs coordination.



