VANCOUVER – Controversies surrounding isotretinoin are mostly unfounded, Dr. Neil Shear said at the World Congress of Dermatology.
“Isotretinoin is the most effective treatment for all grades of acne vulgaris,” added Dr. Shear, professor and chief of dermatology at the University of Toronto Medical School. “Isotretinoin causes fetal malformations, and most preventative strategies around pregnancy have not been completely successful. Isotretinoin does not cause inflammatory disease, nor irritable bowel, but it can, rarely, cause depression,” he said. “If you agree with all those things, I don’t find it very controversial.”
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In fact, there exists “a very good argument” for using isotretinoin as a first-line therapy for some patients with acne, said Dr. Shear. “I would be for it,” he said. “It has its issues, and they do have to be managed, but we know the issues behind systemic antibiotics might be larger than the issues behind isotretinoin.”
Safety concerns about isotretinoin have spurred dozens of lawsuits in the United States, many of which allege that the medication caused inflammatory bowel disease (IBD). But despite split verdicts and millions of dollars awarded to some plaintiffs, the best available evidence does not support a causal association between isotretinoin and IBD, Dr. Shear asserted. He pointed to a large population-based cohort study that found no association between isotretinoin and IBD in its primary analysis, although prespecified secondary analyses linked IBD with both isotretinoin and topical acne medications. “The conclusion could only be that if there is increased IBD, it is associated with acne, not with the therapy,” Dr. Shear said. “The arrow has been pointing us in this direction for over a decade now, and I am hoping there will be bigger studies to show the blame is with acne, not isotretinoin.”
Isotretinoin has been associated with clinical depression, which is sometimes preceded by onset of new headache, Dr. Shear said. He has seen some patients become depressed on the medication, he added. “But untreated acne is associated with depression and even suicidal ideation sometimes. I think it’s quite manageable, personally,” he said. “It’s all part of the risk management of using a medication like isotretinoin. Patients who are depressed with acne, even when they have dry lips and other side effects, are so much happier with isotretinoin.”
In fact, Dr. Shear would not rule out isotretinoin for acne patients who have a history of clinical depression, although he would first consider other options such as decreasing dietary glycemic load or retrying “failed” treatments to ensure that patients gave them an adequate trial, he said.
Because of its high risk of severe fetal malformations, dermatologists who prescribe isotretinoin need to ensure that female patients have a specific plan for using effective birth control, Dr. Shear emphasized. But the risk of birth defects does not negate the need for the drug, he said. “Companies have tried hard to make a similar retinoid that does not affect the fetus and cause birth defects and have not been successful.”
The hypothesis that isotretinoin adversely affects pediatric bone growth has been debunked, Dr. Shear said, in response to a question from the audience, citing a study published in the journal Osteoporosis International.
Dr. Shear reported having no relevant conflicts of interest except having worked with Roche on rituximab. Roche formerly manufactured and marketed isotretinoin (Accutane) in the United States, but no longer does so.