A new study said that some over-the-counter drops meant to soften ear wax can damage the ear and shouldn't be used.

"Patients often complain that wax is blocking their ears and is causing discomfort and sometimes deafness," said Dr. Sam Daniel of the Montreal Children's Hospital. He said they can cause severe inflammation and damage to the eardrum and inner ear.

"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," Daniel said.

Daniel and his team studied 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 analyzed.

"Harmful effects to many of the cells were observed after only one dose," said co-author Dr. Melvin Schloss.

"We believe these findings are applicable to humans," Daniel said. "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 results of the study were published in The Laryngoscope.