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Primidone

Mysoline · ATC code N03AA03

Also known as: Primidon, Mysoline

Key facts
Active substance
Primidone
Drug class
Anticonvulsant agent
ATC code
N03AA03
Authorisation
authorised nationally; no central EU authorisation
Information as of
2026-10-29

Key facts

Primidone is an anticonvulsant. Per the US prescribing information, it is used alone or with other anticonvulsants to control grand mal, psychomotor and focal epileptic seizures.

What it is used for

  • Grand mal, psychomotor and focal epileptic seizures, alone or in combination
  • May control grand mal seizures refractory to other anticonvulsant therapy

Dosing

  • Age 8 years and older, no previous treatment: Days 1 to 3: 100 to 125 mg at bedtime; Days 4 to 6: 100 to 125 mg twice a day; Days 7 to 9: 100 to 125 mg three times a day; from Day 10: 250 mg three times a day
  • Usual maintenance: 250 mg three or four times a day; not to exceed 500 mg four times a day (total daily dose not over 2 g)
  • Children under 8 years: start with 50 mg at bedtime; maintenance 125 to 250 mg three times daily or 10 to 25 mg/kg/day in divided doses
  • Patients on other anticonvulsants: start at 100 to 125 mg at bedtime; transition to monotherapy should take no less than 2 weeks
  • Clinically effective serum level 5 to 12 mcg/mL; individualize the dose

Contraindications

  • Porphyria
  • Hypersensitivity to phenobarbital

Important warnings

  • Abrupt withdrawal may precipitate status epilepticus
  • Antiepileptic drugs increase the risk of suicidal thoughts or behavior; monitor for depression and mood changes
  • The efficacy of a dosage regimen takes several weeks to assess
  • On long-term therapy, complete blood count and SMA-12 test every 6 months

Side effects

  • Most frequent early effects: ataxia and vertigo, which tend to disappear
  • Occasionally: nausea, anorexia, vomiting, fatigue, hyperirritability, emotional disturbances, sexual impotency, diplopia, nystagmus, drowsiness, morbilliform rash
  • Rarely: granulocytopenia, agranulocytosis, red-cell hypoplasia and aplasia; megaloblastic anemia responding to folic acid

Pregnancy and breastfeeding

  • Effects in human pregnancy unknown; reports link anticonvulsants with more birth defects; do not stop if this risks major seizures
  • Neonatal hemorrhage described; vitamin K1 prophylaxis for 1 month before and during delivery; appears in breast milk in substantial quantities

Summary of the official product information, written with AI on 2026-10-29. Every number was checked automatically against the original text. Not reviewed by a physician – the full official text is authoritative.

Full official text →

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For patients

Patient information (US)

This product has no separate US patient information.

Authorisation and brand names by country

Medicines with exactly this active-substance composition, as listed in the national registers – alphabetical and without ranking. Whether a product is currently available is not shown here.

Austria

  • MysolineSanova Pharma Gesmbh · 1 register entry

Source: EMA – Article 57 product data (EU/EEA), as of 2026-10-29

Germany

  • LiskantinDesitin Arzneimittel Gmbh · 2 register entries
  • MylepsinumTeva Gmbh · 1 register entry
  • Primidon HolstenHolsten Pharma Gmbh · 1 register entry

Source: EMA – Article 57 product data (EU/EEA), as of 2026-10-29

Turkey

  • GranmidOSEL İLAÇ SAN. VE TİC. A.Ş. · 1 register entry
  • MysolineEMRE ECZA İLAÇ AŞI SANAYİ TİCARET VE DANIŞMANLIK LTD. ŞTİ. · 1 register entry

Source: TİTCK – Ruhsatlı Beşeri Tıbbi Ürünler Listesi, as of 2026-10-16

USA

  • MysolineBausch Health US, LLC · 1 register entry

Source: U.S. FDA – Drug labels (openFDA/DailyMed), as of 2026-10-29

Brand names in 17 more European countries
Belgium
Mysoline
Czechia
Liskantin
Denmark
Primidon Afortas, Primidon Orifarm
Estonia
Liskantin
Finland
Primidon Afortas
France
Mysoline
Hungary
Sertan
Ireland
Mysoline
Italy
Mysoline
Luxembourg
Mysoline
Malta
Mysoline, Primidone Serb
Netherlands
Mysoline
Norway
Primidon Afortas
Poland
Mizodin
Portugal
Mysoline
Spain
Mysoline
Sweden
Primidon Afortas

EMA – Article 57 product data (EU/EEA), 2026-10-29

Medelix receives no money from pharmaceutical companies. Brand names are listed alphabetically and without ranking.

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Sources

  1. U.S. Food and Drug Administration. Mysoline (Bausch Health US, LLC) – Prescribing Information, 2026-09-10. DailyMed (NLM), 2026-10-29. https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=af593171-dabb-4ea3-b44c-89ed457b2c46
  2. EMA – Article 57 product data (EU/EEA), 2026-10-29. https://www.ema.europa.eu/en/human-regulatory-overview/post-authorisation/data-medicines-iso-idmp-standards-post-authorisation/public-data-article-57-database
  3. EMA – Article 57 product data (EU/EEA), 2026-10-29. https://www.ema.europa.eu/en/human-regulatory-overview/post-authorisation/data-medicines-iso-idmp-standards-post-authorisation/public-data-article-57-database
  4. TİTCK – Ruhsatlı Beşeri Tıbbi Ürünler Listesi, 2026-10-16. https://www.titck.gov.tr/dinamikmodul/85
  5. U.S. FDA – Drug labels (openFDA/DailyMed), 2026-10-29. https://dailymed.nlm.nih.gov/dailymed/
  6. Wikidata (CC0): ATC N03AA.

Editorial: Medelix editorial team · last updated 2026-10-29 · How these pages are made · Report an error

Source: U.S. Food and Drug Administration (FDA), prescribing information, via DailyMed (NLM); public domain. Not advertising, not a treatment recommendation. For questions about your own treatment, ask your doctor or pharmacist.