Isotretinoin-Induced Peripheral Neuropathy: An Enigma

Isotretinoin, a first-generation nonaromatic retinoid, leads to numerous diseases including eye disorders and neurological, gastrointestinal, psychiatric, metabolic, connective tissue, and musculoskeletal diseases. The aim of this study was to investigate the effects of isotretinoin on peripheral nerve functions. The study included 30 patients that were started on isotretinoin due to nodulocystic acne. A thorough neurological and general examination was performed for each patient by a neurologist both at the beginning and end of the study. Laboratory investigations including complete blood count (CBC), serum biochemical analysis, vitamin B12 levels, thyroid function tests, and urine tests were performed to identify the other factors that may affect the functions of peripheral nerves. A neurophysiological examination was performed using an electroneuromyography (EMG) device. The 30 patients comprised 7 (23.3%) men and 23 (76.7%) women, with a mean age of 21.9±3.56 years. No serious side effect occurred in any patient. No motor or sensory values suggestive of neuropathy were observed in any patient. However, significant differences were found between the pre-and post-treatment sensory and motor values of some nerves. Although it did not cause peripheral polyneuropathy, isotretinoin resulted in alterations in the latency, amplitude, and velocity values of peripheral nerves.