title: Does interferon beta-1a impact pure-tone hearing sensitivity among individuals with multiple sclerosis?
abstract: BACKGROUND
  Previous studies reported that particular types of interferon medications might contribute to hearing loss in some patients. The package insert included in the original Food and Drug Administration application for intramuscular interferon beta-1a (Avonex) stated that some patients in the treatment group reported decreased hearing sensitivity.
  
  
  OBJECTIVE
  The purpose of the present investigation was to assess if individuals with multiple sclerosis (MS) taking intramuscular interferon beta-1a have significantly poorer hearing thresholds than those not currently using any disease-modifying therapies.
  
  
  METHODS
  This was a secondary analysis of data collected as part of two larger studies evaluating auditory function in patients with MS. The goal of this analysis was to determine if users of interferon beta-1a do not have significantly worse hearing thresholds than nonusers of disease-modifying therapies, after adjusting for potential confounders. A linear mixed model was fit to the audiometric thresholds of our subjects. This model included interferon beta-1a use, MS disease subtype, gender, test frequency, age, disease duration (number of years), and the Expanded Disability Status Scale score.
  
  
  CONCLUSIONS
  With all subjects included, there is insufficient evidence to say that intramuscular interferon-beta 1a is not ototoxic (in relation to nonuse of a disease-modifying therapy) at all frequencies tested except 3000 and 6000 Hz. After removing two influential subjects, the results indicated that there is statistical support for no ototoxic effect of intramuscular interferon beta-1a at test frequencies from 250 to 6000 Hz. There is insufficient evidence, however, to rule out an ototoxic effect at 8000 Hz. Future studies should further evaluate the effect of interferon on auditory function in patients with MS. Neuroscience nurses should monitor their patients' hearing throughout the course of treatment.
authors.affiliation: Garnett P. McMillan, PhD, is a Biostatistician at NCRAR, Portland VA Medical Center, Portland, OR. Michele Hutter, MS, was a Research Audiologist at the NCRAR, Portland VA Medical Center, Portland, OR. Robert L. Folmer, PhD, is a Research Investigator at NCRAR, Portland VA Medical Center, and Associate Professor, Department of Otolaryngology/Head and Neck Surgery, Oregon Health & Science University, Portland, OR. Debra Wilmington, PhD, was a Research Investigator at NCRAR, Portland VA Medical Center, Portland, OR and an Assistant Professor, Department of Otolaryngology/Head and Neck Surgery, Oregon Health & Science University, Portland, OR; and is currently an Instructor, Department of Biology, College of Arts and Sciences, Washington State University Vancouver, Vancouver, WA. Linda Casiana, MS, CCRP, was a Research Assistant at NCRAR, Portland VA Medical Center, Portland, OR. Mary Fitzpatrick, NP, was a Nurse Practitioner in the Neurology Service, Portland VA Medical Center; and is currently Medical Science Clinical Liaison, Biogen Idec U.S. Medical, Cambridge, MA. David J. Lilly, PhD, was a Research Investigator/Audiologist at NCRAR, Portland VA Medical Center, Portland, OR and is a Professor Emeritus, Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa City, IA. Dennis Bourdette, MD, is Co-Director, Multiple Sclerosis Center of Excellence West, Portland VA Medical Center, Portland, OR and Chair and Roy and Eulalia Swank Family Research Professor, Department of Neurology, Oregon Health & Science University, Portland, OR. Shannon Overs, MD, is a Staff Physician previously associated with the Neurology Service, Portland VA Medical Center, Portland, OR; Department of Neurology, Oregon Health & Science University, Portland, OR; and Novant Health Neurology Specialists, Charlotte, NC. Michelle Cameron, MD, is Staff Neurologist, Neurology Service, Portland VA Medical Center, and Assistant Professor, Department of Neurology, Oregon Health & Scienc
authors.forename: M Samantha
authors.initials: MS
authors.lastname: Lewis
authors.forename: Garnett P
authors.initials: GP
authors.lastname: McMillan
authors.forename: Michele
authors.initials: M
authors.lastname: Hutter
authors.forename: Robert L
authors.initials: RL
authors.lastname: Folmer
authors.forename: Debra
authors.initials: D
authors.lastname: Wilmington
authors.forename: Linda
authors.initials: L
authors.lastname: Casiana
authors.forename: Mary
authors.initials: M
authors.lastname: Fitzpatrick
authors.forename: David J
authors.initials: DJ
authors.lastname: Lilly
authors.forename: Dennis
authors.initials: D
authors.lastname: Bourdette
authors.forename: Shannon
authors.initials: S
authors.lastname: Overs
authors.forename: Michelle
authors.initials: M
authors.lastname: Cameron
authors.forename: Stephen
authors.initials: S
authors.lastname: Fausti
mesh_terms: D000328:Adult; D001301:Audiometry, Pure-Tone / Q000451:nursing*; D001309:Auditory Threshold / Q000187:drug effects*; D005260:Female; D006801:Humans; D000068556:Interferon beta-1a; D016899:Interferon-beta / Q000008:administration & dosage / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000188:drug therapy* / Q000451:nursing*; D012016:Reference Values
chemical_list: D016899:Interferon-beta; D000068556:Interferon beta-1a