acetic acid: clinical use

Prescribing considerations

• Confirm that symptoms arise from the external auditory canal and assess whether swelling or debris may prevent topical delivery.
• Licensed for superficial external-canal infection from age 12; younger children require medical advice.
• Reassess if pain occurs, hearing deteriorates, symptoms worsen or improvement is absent.

Contraindications and cautions

• Known hypersensitivity to acetic acid or any excipient.

Monitoring

• Clinical response, pain and hearing.
• Extension of inflammation or infection beyond the external canal.
• Consider specialist assessment for persistent, recurrent or severe disease.

Clinical pharmacology

Topical acetic acid acidifies the external auditory canal and has local antibacterial activity. Reported susceptible organisms include Haemophilus and Pseudomonas species; activity against Candida is also reported.

Formulation and product differences

• The selected product is a metered ear spray for external auricular use.
• It contains macrogol stearyl ethers, stearyl alcohol, methyl parahydroxybenzoate and propyl parahydroxybenzoate.
• Use under medical supervision if the tympanic membrane is perforated or may be perforated.