Certain over-the-counter earwax softeners can cause severe inflammation and damage to the eardrum and inner ear, say researchers.
The study, led by Dr. Sam Daniel, director of McGill Auditory Sciences Laboratory at The Children's, suggests that use of such medications should be discouraged.
"Patients often complain that wax is blocking their ears and is causing discomfort and sometimes deafness," Daniel said.
"Over-the-counter earwax softeners are used to break-up and disperse this excess wax. However, the effects of these medications on the cells of the ear had not been thoroughly analysed.
"Because some of these products are readily available to the public without a consultation with or prescription from a physician, it is important to make sure they are safe to use. Our study shows that in a well-established animal model, one such product, Cerumenex, is in fact, toxic to the cells of the ear," he added.
In the study, the researchers reviewed the impact of Cerumenex on hearing. In addition, overall toxicity in the outer ear and changes in the nerve cells of the inner ear were analysed.
Dr. Melvin Schloss co-author and MCH Director of Otolaryngology, said: "Harmful effects to many of the cells were observed after only one dose. We observed reduced hearing, severe inflammation, and lesions to the nerve cells."
Daniel added: "We believe these findings are applicable to humans. The animal model we chose has been widely used to test toxicity. In addition, this model has a very similar hearing mechanism. Overall, our findings suggest that Cerumenex has a toxic potential and it should be used with caution."
The study is published in the journal The Laryngoscope.