Isotretinoin (Roaccutane): Treatment and Medication Monitoring

Written by Dr. K on 24 March 2021

Isotretinoin Treatment Plan

Dosage range for Isotretinoin can vary from 0.1mg/kg body weight to over 2mg/kg body weight. One treatment course generally lasts from 4 months to 8 months on average. For cases of acne, Dermatologists often set a target of 120mg/kg to 140mg/kg body weight as the total cumulative dose for the entire treatment course. This is believed to reduce rates of relapse in patients with severe acne. Despite this, many Dermatologists also prescribe lower doses, around 10mg/day.

Exact prescription doses of Isotretinoin depends on the following parameters:

  • Patient body weight
  • Severity of the acne
  • The specific skin condition or other disease that is being treated
  • Initial response to treatment
  • Severity of side effects experienced by the patient
  • Concurrent treatments used at the same time
  • Dermatologist preference
  • Patient compliance

Isotretinoin works best after consuming a high-fat meal, due to its increased absorption. This is owing to the fact that its derivative, Vitamin A, is lipophilic (dissolves well in fats). Absorption is believed to be doubled with a high-fat meal, compared to when it is consumed on an empty stomach. 

Isotretinoin should generally be taken at the same time every day, due to its half-life of around 22 hours.

Alcohol consumption during Isotretinoin treatment can cause liver failure, pancreatitis, hypertriglyceridemia, liver toxicity and in extreme cases even be fatal. Avoid alcohol consumption throughout your treatment course of Isotretinoin.

Drug Monitoring

Before starting Isotretinoin, your doctor will require a baseline blood test to be done. This will assess for the following:

  • full blood count
  • renal function
  • full lipid profile – cholesterol, triglycerides, lipids
  • liver function

If there are any issues with the above, your doctor will let you know.

Isotretinoin has been known to occasionally cause liver dysfunction and high cholesterol and high lipids. For these reasons, your doctor may require you to have multiple blood tests at intervals throughout your treatment course.

Drug Interactions

Before use of any medication or supplements, please speak to your doctor.

Isotretinoin has the following interactions with this list of medications:

  • Vitamin A – this may be present in over-the-counter multivitamins supplements
  • Demeclocycline
  • Doxycycline
  • Lymecycline
  • Minocycline
  • Oxytetracycline
  • Tetracycline
  • Tigecycline
  • Warfarin – INR monitoring is crucial
  • Phenytoin
  • Mini pill progesterone contraceptives
  • St John’s Wort
  • Systemic corticosteroids

Prior to your treatment course, your doctor will review every medication that you are taking, to ensure there is no drug interaction. Please also let your doctor know of any supplements or over-the-counter medications or alternative therapies you are taking.



  1. Advice on the safe introduction and continued use of isotretinoin in acne in the UK 2010 – MJD Goodfield, NH Cox, A Bowser, JC McMillan, LG Millard, NB Simpson, AD Ormerod, BJD, Vol. 162, No. 5, June 2010 (p1172-1179)
  2. Mollan SP, Woodcock M, Siddiqi R, Huntbach J, Good P, Scott RA. Does use of isotretinoin rule out a career in flying? Br J Ophthalmol. 2006 Aug;90(8):957-9. PubMed.
  3. Accessed on 24.3.2021
  4. NICE BNF UK – Isotretinoin

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