MedeliX
Start asking

Cenobamate

Ontozry · ATC code N03AX

Key facts
Active substance
Cenobamate
Drug class
Anticonvulsant agent
ATC code
N03AX
Authorisation
centrally authorised across the EU (EMA)
Dosage forms
Ontozry 12.5 mg tablets / Ontozry 25 mg film-coated tablets / Ontozry 50 mg film-coated tablets
Marketing authorisation holder
Angelini Pharma S.p.A
Information as of
2026-10-27

Key facts

Cenobamate (Ontozry) is an anti-epileptic used as adjunctive treatment of focal-onset seizures in adults with epilepsy not adequately controlled despite at least 2 anti-epileptic medicines.

What it is used for

  • Adjunctive treatment of focal-onset seizures with or without secondary generalisation in adults previously treated with at least 2 anti-epileptic medicines

Dosing

  • Start at 12.5 mg per day, titrated gradually every two weeks to the target dose of 200 mg per day
  • Titration steps: 12.5 mg, 25 mg, 50 mg, 100 mg, 150 mg, then 200 mg; must not be accelerated because of serious adverse reactions
  • If needed, increase by 50 mg/day every two weeks up to a maximum of 400 mg daily
  • Renal impairment: use with caution, maximum 300 mg/day; not in end-stage renal disease or haemodialysis
  • Mild to moderate hepatic impairment: maximum 200 mg/day; not in severe hepatic impairment
  • Discontinue gradually over at least 2 weeks

Contraindications

  • Hypersensitivity to the active substance or any excipient
  • Familial short-QT syndrome

Important warnings

  • Suicidal ideation and behaviour; patients should be monitored
  • DRESS (can be life-threatening) reported with higher starting doses and rapid titration
  • Dose-dependent shortening of the QTcF interval
  • Elderly: cautious dose selection

Side effects

  • Most common: somnolence, dizziness, fatigue, headache
  • Most common reasons for discontinuation: ataxia, dizziness, somnolence, nystagmus, vertigo, diplopia (dose dependent)
  • Common: confusional state, irritability; uncommon: hypersensitivity

Interactions

  • May reduce exposure of CYP3A4 and 2B6 substrates and increase exposure of CYP2C19 substrates
  • CNS depressants (alcohol, barbiturates, benzodiazepines): higher risk of neurological adverse reactions; doses may need reduction
  • Oral contraceptives: additional non-hormonal contraception needed
  • Interactions with other anti-epileptics (e.g. phenytoin) in the full text

Pregnancy and breastfeeding

  • Not recommended in women of childbearing potential not using contraception; with oral contraceptives use additional non-hormonal methods until 4 weeks after stopping

Summary of the official product information, written with AI (Claude, Anthropic) on 2026-10-28. Every number was checked automatically against the original text. Not reviewed by a physician – the full official text is authoritative.

Full official text →

Common questions – ask Medelix

For patients

Package leaflet, verbatim

Package leaflet for patients →

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.

EU – centrally authorised (all member states)

  • OntozryAngelini Pharma S.p.A · EMEA/H/C/005377

Source: European Medicines Agency (EMA), product information

Brand names in 3 more European countries
Iceland
Ontozry
Liechtenstein
Ontozry
Norway
Ontozry

EMA – Article 57 product data (EU/EEA), 2026-10-28

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

Other substances in the same group

Another question about this substance?

Medelix answers clinical questions from guidelines, studies and product information – every claim with its source.

Sources

  1. European Medicines Agency. Ontozry – EPAR, Product Information (OF THE TEXT Detailed information on this medicinal product i). 2026-10-27. https://www.ema.europa.eu/en/documents/product-information/ontozry-epar-product-information_en.pdf
  2. Wikidata (CC0): ATC N03AX.

Editorial: Medelix editorial team · last updated 2026-10-27 · How these pages are made · Report an error

Source: European Medicines Agency (EMA), product information. Not advertising, not a treatment recommendation. For questions about your own treatment, ask your doctor or pharmacist.