Roaccutane cumulative dosage

Many dermatologists believe in a cumulative dose when prescribing Roaccutane (recommended by the BNF.org guidelines).

The idea is that the patient must take a certain amount of Istotretinoin to avoid relapsing in the future.

If the patient has a relapse (acne returns) a second course may be recommended at least 8 weeks, after their first course has ended.

For children and adults over 12 years old, Roaccutane dosage can range from 500 micrograms/kg to 150 mg/kg per 2.2 pounds of body weight. This is usually divided into two doses for 14 to 24 weeks.

For the sake of this post we will say that the cumulative dose is 120 mg (which seems to be a popular dose on this site).

The cumulative dose is worked out by multiplying your body weight in kg by 120mg. An example of how the cumulative dose could be worked out is shown below:

I weigh about 57kg, so the dermatologists has worked with the figure 60kg as a rounded up figure. Thus: 60kg X 120mg = 7,200mg cumulative dose of Roaccutane.

At 60mg per day (my maximum recommended dose for my weight), the Dermatologist then calculates how many days are required to reach this target dose:

7,200mg divided by 60mg = 120 days (i.e. about 4 months).


Please note:
these figures will vary depending on the weight of patient, height of patient, dermatologist’s professional opinion and severity of the patient’s acne.