Context: Oral isotretinoin, a systemic retinoid and a vitamin A derivative, has been widely utilized to treat acne in both adult and pediatric populations. Additionally, systemic retinoids have also been utilized to treat neuroblastoma in pediatric patients. Common side effects associated with oral isotretinoin include dry eyes, dry mouth, elevated liver enzymes, depression, and arthralgia. Less common side effects of isotretinoin include hearing loss, pseudotumor cerebri, anaphylaxis, and skeletal abnormalities including growth arrest. The U.S. Food and Drug Administration (FDA) has received reports of premature epiphyseal closure in patients treated with isotretinoin retinoids, which are commonly prescribed by primary care providers as a treatment for acne. It is important to raise awareness of the potential side effects of isotretinoin to enable informed treatment decisions before beginning an isotretinoin regimen.
Objectives: This chapter aims to elucidate that isotretinoin, given at various doses and durations, has been associated with growth plate abnormalities, which can lead to premature epiphyseal closure.
Methods: Two databases were utilized for the literature review and were conducted at different time periods. Our literature review was conducted between December 2020 and June 2021, utilizing PubMed with the following search terms: “isotretinoin” and “isotretinoin and premature epiphyseal closure.” In April 2021, we searched the FDA’s “Drug Data and Adverse Event Report System” utilizing the terms “isotretinoin” and “epiphysis premature fusion.” We included in our query reports of patients worldwide under 18 years of age with premature epiphyseal closure or growth plate damage secondary to isotretinoin. Studies published in English between 1980 and 2020 were also included, as well as background sources relating to an isotretinoin profile with side effects and dosing. We narrowed our search to exclude patients with a history of growth plate disorders due to trauma, malignancy, or other pathological processes, as well as patients with growth arrest due to endocrine factors. Growth plate abnormalities associated with retinoid derivatives other than isotretinoin were also excluded.
Results: A total of 28 items were selected for our literature review including: one FDA drug label, one FDA website of adverse reactions, 19 supplemental articles, six case reports, and one case series of premature epiphyseal closure secondary to isotretinoin. The FDA received 41 reports worldwide of premature epiphyseal closure related to isotretinoin in patients under 18 years of age. Additionally, premature epiphyseal closure and growth plate abnormalities occurred in nine patients with various durations and doses of isotretinoin ranging from the lowest dose of 0.5 mg/kg/day for a few months to 3.5 mg/kg/day for years.
Conclusions: Isotretinoin-induced premature epiphyseal closure and growth plate deformities seem to be linked to higher doses of isotretinoin for the duration of months to years. There have been reported cases of premature epiphyseal closure in individuals receiving therapeutic doses of isotretinoin for acne treatment, which are much lower compared to the high doses utilized for neuroblastoma. Based on this study, isotretinoin appears to impact the growth plates of proximal tibia and distal femur. A cause-and-effect relationship between isotretinoin and premature epiphyseal closure cannot be concluded.