Isotretinoin usage and duration of the course

Patient: Hi Doctor,my name is Vijay.gender: maleage: 29 yearsI would like to know how long I can use isotretinoin without having any side effects.Previously I have used tretiva 20 and isotane 20 for a month and stopped using them.My acne problem is reduced. Can I continue the drug if acne comes back ?Can I use isotretinoin whenever more pimples appear on my face?

Symptoms: Acne and acne scars