Myorisan Dosage

Generic name: isotretinoin
Dosage form: capsule, liquid filled

This dosage information does not include all the information needed to use Myorisan safely and effectively. See full prescribing information for Myorisan.

The information at is not a substitute for medical advice. ALWAYS consult your doctor or pharmacist.

Myorisan should be administered with a meal (see PRECAUTIONS: Information for Patients).

The recommended dosage range for Myorisan is 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 manifested on the trunk may require dose adjustments up to 2 mg/kg/day, as tolerated. Failure to take Myorisan with food will significantly decrease absorption. Before upward dose adjustments are made, the patients should be questioned about their compliance with food instructions.

The safety of once daily dosing with Myorisan has not been established. Once daily dosing is not recommended.

If the total nodule count has been reduced by more than 70% prior to completing 15 to 20 weeks of treatment, the drug may be discontinued. After a period of 2 months or more off therapy, and if warranted by persistent or recurring severe nodular acne, a second course of therapy may be initiated. The optimal interval before retreatment has not been defined for patients who have not completed skeletal growth. Long-term use of Myorisan, even in low doses, has not been studied, and is not recommended. It is important that Myorisan be given at the recommended doses for no longer than the recommended duration. The effect of long-term use of Myorisan on bone loss is unknown (see WARNINGS: Skeletal: Bone Mineral Density, Hyperostosis, and Premature Epiphyseal Closure).

Contraceptive measures must be followed for any subsequent course of therapy (see PRECAUTIONS).

Table 4 Myorisan Dosing by Body Weight (Based on Administration With Food)
See DOSAGE AND ADMINISTRATION: the recommended dosage range is 0.5 to 1 mg/kg/day.
Body Weight Total mg/day
kilograms pounds 0.5 mg/kg 1 mg/kg 2 mg/kg*
40 88 20 40 80
50 110 25 50 100
60 132 30 60 120
70 154 35 70 140
80 176 40 80 160
90 198 45 90 180
100 220 50 100 200


Access the iPLEDGE system via the internet ( or telephone (1-866-495-0654) to obtain an authorization and the "do not dispense to patient after" date. Myorisan must only be dispensed in no more than a 30-day supply.


A Myorisan Medication Guide must be given to the patient each time Myorisan is dispensed, as required by law. This Myorisan Medication Guide is an important part of the risk management program for the patient.