Greeting, Doctor. I Have An Aunt, Recently She Mention About

Greeting, Doctor.

I have an aunt, recently she mention about having hearing problem. So, yesterday I brought her to hospital, to an ENT specialist. Apparently there is cerumen impaction in both of her ears. The doctor prescribed phenol glycerin to soften the ear wax and to return after 1 week. But, today after using the cerumenolytic she experience stinging pain in her ear and vertigo. What might cause this ? Should she continue using it ?

Thanks before and best regard.