QUESTIONS
2 What is ear wax and what is available to soften and dissolve it?
3 How should ear drops be used?

ANSWER

2. Ear wax (cerumen) is a complex, oily fluid secreted by sebaceous and apocrine glands in the external auditory canal, which combines with exfoliated skin cells to form a protective waxy layer. This is normally moved outwards by movement of the jaw in speaking and chewing, and removed by washing. In some individuals, however, excessive cohesive cerumen is produced. This forms a waxy plug that affects hearing and causes discomfort. Generally, syringing is necessary to remove ear wax but cerumenolytics can be used in advance to soften, loosen and partially dissolve it. Several approaches are taken, including the use of aqueous and oily solvents and surfactants, and oxygen generation to facilitate the penetration of water into the plug.
Fixed and volatile oils: Ear wax contains a high proportion of oily components, so it is logical to assume that it can be dissolved, at least partially, by oils. The BNF recommends the use of olive oil or almond oil alone to soften wax before removal, and several proprietary ear drop products contain olive oil alone. Arachis (peanut) oil is a constituent of other products, and one contains this, together with rosemary and cajuput oils.

Urea hydrogen peroxide: Several ear drop brands contain 5% urea hydrogen peroxide in a glycerol base. In contact with tissues containing the enzyme catalase, hydrogen peroxide releases its oxygen to create effervescence, which helps to break up wax by a mechanical action. Glycerol assists in softening the wax and urea increases penetration of the solution into the plug.

Sodium Bicarbonate Ear Drops BP contains 5% sodium bicarbonate and 30% glycerol in water. It is recommended as effective in the BNF.

Docusate sodium is a surface active agent that increases water penetration into the wax plug. It is the sole component of two proprietary products.

3.
€¢ It is best to have another person instil the ear drops.
€¢ Before use, the drops should be slightly warmed by holding the container in the hands for a few minutes. €¢ The patient should lay their head on a flat surface such as a table, with the affected ear uppermost.
€¢ The auricle (pinna) should be lifted upwards and backwards in adults, or downward and backwards in children, to straighten the ear canal.
€¢ The requisite number of drops should be instilled.
€¢ The tragus (the small projection in front of the external opening) should be pressed gently once or twice, to assist the drops down the ear canal and to expel air bubbles.
€¢ The patient should remain with their head down for at least five minutes. A cotton-wool plug moistened with the drops should be placed into the ear.
€¢ Unless directed otherwise, the drops should be used night and morning for three or four days before syringing.