Some over-the-counter "earwax softeners" can cause severe inflammation and damage to the eardrum and inner ear, say researchers at The Montreal Children's Hospital.
The researchers say that the effects of these medications on the cells of the ear had not been thoroughly analyzed and that they found that one product in particular, Cerumenex, is actually toxic to ear cells when given to animals with perforated eardrums.
Dr. Sam Daniel the lead investigator of the study and director of McGill Auditory Sciences Laboratory at The Children's Hospital, thinks use of the product should be discouraged.
"Our study shows that in a well-established animal model, one such product, Cerumenex, is in fact, toxic to the cells of the ear," says Dr. Daniel.
The results of the study were recently published in The Laryngoscope.
Over-the-counter earwax softeners are used to break up and disperse excess wax that can build up in the ears and cause discomfort and occasionally, deafness. The products are available to the public without a consultation with or prescription from a physician. But Daniel says they have not been well studied.
Dr. Daniel and his team studied the impact of Cerumenex on the hearing of 20 chinchillas whose eardrums were perforated. All of the animals with perforated eardrums developed hearing loss.
Study co-author Dr. Melvin Schloss, the MCH Director of Otolaryngology, says they found the products caused problems after just one dose.
"We observed reduced hearing, severe inflammation, and lesions to the nerve cells," says Schloss.
Although the tests were conducted on chinchillas, the researchers believe the results would apply to humans as well.
"Overall, our findings suggest that Cerumenex has a toxic potential and it should be used with caution," says Daniel.
Health Canada says the agency is aware of the study, and is currently investigating the issue.
