Efficacy of Acetylcysteine in Patients Undergoing Surgery for Otosclerosis

In otosclerosis, one of the tiny bones of the middle ear is unable to move normally. Sounds cannot be transferred to the inner ear and a conductive hearing loss ensues. The disorder is usually treated by an operation where the bone is replaced by a prosthesis. This restores hearing at low sound frequencies. At high frequencies, surgery is less effective. The smaller effect at high frequencies is probably caused by surgically induced inner ear damage. Animal studies have shown that the drug acetylcysteine can protect the inner ear against damage. It is not known whether the drug has similar effects in humans. This study will assess the efficacy of acetylcysteine in patients undergoing surgery for otosclerosis.

150 mg / kg body weight. Drug is dissolved in NaCl to a final volume of 300 mL. This volume is infused starting one hour prior to surgery, and continued 1 hour after the end of surgery.

Inclusion Criteria: Otosclerosis where surgery is planned Air / bone gap larger than 20 dB Normal middle ear status Exclusion Criteria: Hypersensitivity to acetylcysteine Deafness on the other ear Stapedotomy previously performed on the ear Pregnancy Asthma

Bagger-Sjoback D, Stromback K, Hakizimana P, Plue J, Larsson C, Hultcrantz M, Papatziamos G, Smeds H, Danckwardt-Lilliestrom N, Hellstrom S, Johansson A, Tideholm B, Fridberger A. A randomised, double blind trial of N-Acetylcysteine for hearing protection during stapes surgery. PLoS One. 2015 Mar 12;10(3):e0115657. doi: 10.1371/journal.pone.0115657. eCollection 2015.