What are the side effects of isotretinoin?

Isotretinoin is a potent teratogen. Of the pregnancies that have occurred in patients taking isotretinoin, one third have resulted in spontaneous abortion, one third ended in therapeutic abortion, and of the one third that continued to term, 20% showed a major fetal malformation, including those of the brain, heart, and ears. Many of these patients, who had a pregnancy while taking isotretinoin, were pregnant when the drug was started. When considering treatment with isotretinoin in females of childbearing age, the FDA requires documentation of two negative pregnancy tests. Contraceptive counseling must be done and documented on the patient’s chart, and two forms of birth control are recommended for the duration of therapy plus 6 weeks posttherapy. Therapy should be started on the third day of the menstrual cycle with a negative pregnancy test to ensure that the patient is not pregnant when therapy is initiated.


Other side effects of isotretinoin include dry skin, lips, and eyes, dry mucous membranes with nosebleeds, headache (including rare instances of pseudotumor cerebri), muscle and backaches, hypertriglyceridemia, increased liver function tests, and depression (see next question). These should be discussed in detail with the patient prior to starting therapy and documentation of the discussion made in the chart. There are also several case reports of inflammatory bowel disease (IBD) being triggered by isotretinoin use. A review of adverse events reported to the United States FDA Medwatch scheme over a 5-year period (1997 to 2002) revealed 85 cases of IBD, of which the causal association with isotretinoin was considered probable or highly probable in 73% of cases.

Reddy D, Siegel CA, Sands BE, et al: Possible association between isotretinoin and inflammatory bowel disease, Am J Gastroenterol 101:1569–1573, 2006.