Accutane (isotretionoin) is prescribed for patients suffering from severe forms of nodular acne that did not respond well to other ways of treatment. Taking Accutane during pregnancy is fraught with severe birth defects in the baby, which is why every woman of a child-bearing potential must sign a special iPLEDGE agreement where she promises to use at least two reliable methods of birth control. Being allergic to the active ingredient of this medicine (isotretinoin) is a direct contraindication. You will probably not be able to take Accutane and your health care provider will recommend you an alternative. In addition to some other side effects this medicine can affect your vision at night. This side effect usually occurs suddenly at any point of the treatment, so you should be careful when operating machinery or driving a car at this time of the day.