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Antioxidant / synthetic ubiquinone analogue Pregnancy: UK SPC section 4.6: 'The safety of idebenone in pregnant women has not been established. Animal studies do not indicate direct or indirect harmful effects with respect to reproductive toxicity. Idebenone should only be administered to pregnant women or women of child-bearing potential likely to become pregnant if it is considered that the benefit of the therapeutic effect outweighs any potential risk.' Breast-feeding: animal data show excretion of idebenone in milk and 'a risk to the suckling child cannot be excluded'; decide between stopping breast-feeding or stopping Raxone, weighing the benefit of each. Fertility: no human data.

Idebenone

Brand names: Raxone

Idebenone is a synthetic short-chain benzoquinone, structurally related to coenzyme Q10, used in the treatment of visual impairment in Leber's hereditary optic neuropathy.

Adult dose

Dose: Leber's hereditary optic neuropathy (LHON) — 900 mg per day, given as 300 mg three times a day, with food
Route: Oral. 'Raxone film-coated tablets should be swallowed whole with water. The tablets should not be broken or chewed. Raxone should be administered with food because food increases the bioavailability of idebenone.' The sourced product is the 150 mg film-coated tablet, so each 300 mg dose is made up of two tablets.
Frequency: Three times a day
Max: 900 mg per day (300 mg three times a day) is the only dose the SPC states — no higher dose, and no separate ceiling, is given for this indication.
Verbatim source wording (UK SPC section 4.2, Posology): 'The recommended dose is 900 mg/day idebenone (300 mg, 3 times a day).' DURATION: 'Data regarding continuous treatment with idebenone for up to 24 months are available as part of a Natural History controlled open label clinical trial.' ELDERLY: 'No specific dose adjustment is required for the treatment of LHON in elderly patients.' The indication wording 'LHON' is the SPC's own — it appears in section 4.2 (elderly and paediatric paragraphs) and in section 4.8 ('adverse reactions emerging from clinical trials in LHON patients'). EXCIPIENT CAUTIONS (section 4.4): 'Raxone contains lactose. Patients with rare hereditary problems of galactose intolerance, total lactase deficiency or glucose-galactose malabsorption should not take Raxone'; 'Raxone contains sunset yellow (E110) which may cause allergic reactions.' CHROMATURIA (section 4.4): the coloured metabolites 'may cause chromaturia, i.e. a reddish-brown discoloration of the urine. This effect is harmless, not associated with haematuria, and does not require any adaptation of dose or discontinuation of treatment' — but 'caution should be exercised to ensure that the chromaturia does not mask changes of colour due to other reasons (e.g. renal or blood disorders).'

Paediatric dose

Route: Oral
Frequency: Not applicable — no paediatric regimen is given
Max: Not applicable — no paediatric posology is stated
NO PAEDIATRIC DOSE IS PUBLISHED, and none has been derived or scaled. Verbatim source wording (UK SPC section 4.2, Paediatric population): 'The safety and efficacy of Raxone in LHON patients under 12 years of age have not yet been established. Currently available data are described in sections 5.1 and 5.2, but no recommendation on posology can be made.' Verify any use in a child against a children's formulary and a specialist neuro-ophthalmology service.

Dose adjustments

Renal

No dose adjustment is stated. UK SPC section 4.2: 'Patients with hepatic or renal impairment have been investigated. However, no specific posology recommendations can be made. Caution is advised in treatment of patients with hepatic or renal impairment, since adverse events have resulted in temporary interruption or discontinuation of treatment... In the absence of sufficient clinical data, caution should be exercised in patients with renal impairment.'

Hepatic

No dose adjustment is stated. UK SPC sections 4.2 and 4.4: no specific posology recommendation can be made; 'Adverse events have been reported in patients with hepatic impairment, which have resulted in temporary interruption or discontinuation of treatment.'

Dose independently re-sourced from UK Summary of Product Characteristics (SPC) via the eMC — clinician-reviewed. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

  • Hypersensitivity to the active substance or to any of the excipients (UK SPC section 4.3 — this is the only contraindication listed)
  • Not listed as a contraindication but stated as a do-not-use in section 4.4: 'Patients with rare hereditary problems of galactose intolerance, total lactase deficiency or glucose-galactose malabsorption should not take Raxone' (the tablets contain lactose)

Side effects

  • Most commonly reported (section 4.8): 'mild to moderate diarrhoea (usually not requiring the discontinuation of the treatment), nasopharyngitis, cough and back pain'
  • Very common: nasopharyngitis; cough
  • Common: diarrhoea; back pain
  • Not known: bronchitis; agranulocytosis, anaemia, leukocytopenia, thrombocytopenia, neutropenia; blood cholesterol and triglycerides increased; seizure, delirium, hallucinations, agitation, dyskinesia, hyperkinesia, poriomania, dizziness, headache, restlessness, stupor; nausea, vomiting, anorexia, dyspepsia; raised ALT, AST, alkaline phosphatase, lactate dehydrogenase, gamma-glutamyltransferase and bilirubin, hepatitis; rash, pruritus; pain in extremity; azotaemia, chromaturia; malaise

Interactions

  • Idebenone is a mild in vivo inhibitor of CYP3A4 — after repeated administration of 300 mg three times daily, midazolam Cmax and AUC rose by 28% and 34% respectively, so 'CYP3A4 substrates known to have a narrow therapeutic index such as alfentanil, astemizole, terfenadine, cisapride, cyclosporine, fentanyl, pimozide, quinidine, sirolimus, tacrolimus, or ergot alkaloids (ergotamine, dihydroergotamine) should be administered with caution in patients receiving idebenone' (section 4.5)
  • 'Idebenone may inhibit P-glycoprotein (P-gp) with possible exposure increases of, e.g., dabigatran etexilate, digoxin or aliskiren. These medicines should be administered with caution in patients receiving idebenone' (section 4.5)
  • No systemic inhibition of CYP1A2, 2B6, 2C8, 2C9, 2C19, 2D6 or 3A4 in vitro at clinically relevant concentrations, and no induction of CYP1A2, CYP2B6 or CYP3A4 (section 4.5)

Monitoring

  • 'Patients should be regularly monitored according to local clinical practice' (UK SPC section 4.4)
  • Liver and renal status — caution in hepatic or renal impairment, where adverse events have led to temporary interruption or discontinuation of treatment (sections 4.2 and 4.4)
  • Urine colour: chromaturia (reddish-brown urine) is a harmless drug effect, but check it is not masking discolouration from another cause such as a renal or blood disorder (section 4.4)

Clinical monograph

How it works

It is thought to act as an antioxidant and electron carrier, supporting mitochondrial electron transport and ATP production while reducing oxidative stress in affected retinal ganglion cells.

Prescribing in practice

  • Discontinue if there is no evidence of benefit after an adequate treatment period, and review response according to the SPC, as not all patients recover vision.
  • It may discolour urine, which is harmless but worth flagging to avoid alarm.
  • Use cautiously in hepatic or renal impairment and review concomitant medication as advised in current prescribing references.

Monitoring

Monitor visual acuity periodically to assess response and inform decisions on continuing therapy.

Counselling the patient

  • Explain that any visual recovery is typically gradual and not guaranteed.
  • Take the medicine with food as directed.
  • A reddish-brown discolouration of urine is expected and not harmful.

Evidence & guidelines

Idebenone is approved for Leber's hereditary optic neuropathy on the basis of trials demonstrating recovery of visual acuity in a proportion of treated patients.

Reference: NICE HST7; SmPC; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

Pathways