This medication is used to treat earwax buildup. It helps to soften, loosen, and remove the earwax. Too much earwax can block the ear canal and reduce hearing. This medication releases oxygen and starts to foam when it comes in contact with the skin. The foaming helps break up and remove the earwax. How to use carbamide peroxide otic This medication is for use only in the ear. Apply this medication into the ear, usually twice daily or as directed by your doctor. Do not use this medication for more than 4 days at a time unless your doctor instructs you to. Follow all directions on the product package. If you are uncertain about any of the information, consult your doctor or pharmacist.