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Systemic retinoid (Vitamin A derivative) / Anti-acne

Isotretinoin

Brand names: Roaccutane, Rizuderm

Isotretinoin is an oral retinoid used by specialists for severe or treatment-resistant acne; it can produce long-lasting remission.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

US labelling (FDA)

Reference — US labelling, may differ from UK

DOSAGE AND ADMINISTRATION Isotretinoin capsules should be administered with a meal (see PRECAUTIONS: Information for Patients ). The recommended dosage range for isotretinoin capsules are 0.5 to 1 mg/kg/day given in two divided doses with food for 15 to 20 weeks. In studies comparing 0.1, 0.5, and 1 mg/kg/day 8 , it was found that all dosages provided initial clearing of disease, but there was a greater need for retreatment with the lower dosages. During treatment, the dose may be adjusted according to response of the disease and/or the appearance of clinical side effects – some of which may be dose related. Adult patients whose disease is very severe with scarring or is primarily …

Source: US FDA prescribing information (openFDA / DailyMed), label dated 2024-06-26. Accessed 2026-06-12. US dosing and indications can differ from UK practice — use UK sources for prescribing decisions.

Clinical monograph

How it works

It is a vitamin-A derivative that reduces sebum production, normalises follicular keratinisation and has anti-inflammatory effects.

Prescribing in practice

  • It is highly teratogenic — it must only be used within a Pregnancy Prevention Programme (effective contraception, regular pregnancy testing, limited prescription duration) in those able to become pregnant.
  • Mucocutaneous dryness (lips, skin, eyes) is near-universal; it raises lipids and liver enzymes and can cause musculoskeletal effects.
  • Mood changes and (rarely) sexual dysfunction are subject to MHRA monitoring — counsel patients and families to report mood or sexual symptoms.

Monitoring

Check lipids and liver function; in those able to become pregnant follow the Pregnancy Prevention Programme; review mood and skin/mucosal effects.

Counselling the patient

  • Do not become pregnant — use the required contraception and pregnancy testing; it can severely harm a baby.
  • Dry lips, skin and eyes are expected — use lip balm and moisturiser; use sun protection.
  • Report low mood, thoughts of self-harm, or any sexual problems.

Evidence & guidelines

A specialist treatment for severe acne, used within a strict Pregnancy Prevention Programme and MHRA monitoring (NICE NG198).

Reference: MHRA Retinoid PPP; BAD Acne Guidelines; NICE CG184; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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