EFFECTS OF ORAL ISOTRETINOIN ON HUMAN AUDITORY BRAIN-STEM RESPONSE

Background: Accumulating evidence suggests that synthetic retinoids ma y be capable of affecting the differentiation and growth of nervous ti ssue in vivo and in vitro. On the other hand, adverse reactions concom itant with brainstem involvement definitely or probably related to ora l retinoid therapy have been reported in a small number of patients. O bjective: The purpose of the present study was to substantiate the pos sible effects of oral isotretinoin on the synaptic activity and propag ation of action potentials along the nerve fibers. Methods: The audito ry brainstem response of 33 patients with severe nodulocystic acne bef ore and 3 weeks after the onset of oral isotretinoin administration wa s investigated using auditory evoked potentials. Results: The paired a nalysis of the response variables before and after treatment failed to reveal any statistically significant differences. However, a marked i ncrease in latencies and interpeak latencies and a decrease in amplitu des for both ears were found in 3 patients after therapy. Conclusions: It seems reasonable to suggest that these subclinical changes may be due to an isotretinoin-induced synaptic malfunction or to a conduction defect in the auditory nerve fibers.