Efeito de fármacos ototóxicos na audição de recém-nascidos de alto risco

PURPOSE: To calculate the incidence of sensorineural hearing loss (SNHL), to verify if there is a causal association between the use of ototoxic drugs and SNHL, and to establish the frequency of genetic mutations related to SNHL in high risk newborns. METHODS: The study was a retrospective and prospective cohort research with 250 children. Data was gathered from subjects' charts and with their caregivers. Moreover, subjects were submitted to auditory evaluation with distortion product otoacoustic emissions, timpanometry, visual reinforcement audiometry, auditory brainstem response and transient otoacoustic emissions. The study of the genetic mutation 35delG, and the mitochondrial mutations A1555G and A7445G was essential to evaluate the possibility that SNHL had a non-syndromic genetic origin. The association between the medicine use and the occurrence of hearing loss had been analyzed. RESULTS: The incidence of SNHL in high risk newborns was 11.6%, and causal associations between SNHL and the drugs administered were: amikacin and cefotaxime (OR=5.35), cefotaxime and furosemide (OR=7.02), ceftazidime and vancomycin (OR=9.12). The frequencies of the mutation 35deIG and mitochondrial mutations A1555G and A7445G were, respectively, 0.8% and 0%. CONCLUSION: The incidence of SNHL in high risk newborns was high, showing an important causal relation with the use of ototoxic drugs and a small relation with genetic mutations.