Otitis externa. Otitis externa or inflammation of the skin of the external auditory canal may be due to infections with bacteria, viruses, or fungi or secondary to skin disorders such as eczema, although more than one factor is often responsible for chronic otitis externa. The treatment includes thorough cleansing and the use of appropriate antibiotic eardrops, often containing a corticosteroid as well, even though some have doubted the value of topical antibiotics. Eardrops containing aminoglycosides, such as gentamicin, neomycin, or polymixins should not be used when the eardrum is perforated because of the risk of ototoxicity.
A solution of acetic acid 2 % acts as an antifungal and antibacterial in the external ear canal. It may be used to treat mild otitis externa but in severe cases an anti-inflammatory preparation with or without an anti-infective drug is required. Solutions containing an anti-infective and a corticosteroid are used for treating cases where infection is present with inflammation and eczema.
Otitis media. Otitis media or inflammation of the middle ear can be acute or chronic, serous (with effusion; secretary) or supportive local treatment of acute otitis media is ineffective and there is no place for drops containing a local anaesthetic. Many attacks are viral in origin and need only treatment with a simple analgesic such as paracetamol for pain. Sever bacterial infection should be treated with systemic antibiotics. The organisms recovered from patients with chronic otitis media are often opportunists living in the debris, keratin, and necrotic bone present in the middle ear and mastoid. Thorough cleansing with an aural suction tube may completely resolve infection of many years duration.
Acute exacerbations of chronic infection may require systemic antibiotics.
Acetic Acid
Solution (ear drop), 2 %
See notes above
Chloramphenicol
Solution (ear drop), 1 %, 2 %, 5 %
Indications: - used in the treatment of bacterial infection in otitis externa.
Cautions: - over growth with non-susceptible organisms. Avoid prolonged use
Side effects: - high incidence of sensitivity reactions to vehicle, optic and peripheral neuritis.
Drug interactions: - alfentanil, chlorpropamide, phenytoin, tolbutamide, rifampicin, warfarin, vitamin B12, folic acid
Contraindications: - hypersensitive to the drug or any ingredients in the formulations; perforated tympanic membrane. Mothers receiving otic chloramphenicol should not breast-feed their infants.
Dose and Administration:
Chloramphenicol 5 % in propylene glycol; apply 2 - 3 drops into the ear 2 - 3 times daily
Storage: - Store below 300C in a tight container protected from freezing
Clotrimazole
Solution (ear drop), 1 %
Indications: - fungal infection in otitis externa.
Side effects: - occasional local irritation or sensitivity
Dose and Administration:
Ear, apply 2 - 3 times daily continuing for at least 14 days after disappearance of infection.
Gentamicin
Solution (ear drop), 0.3 %
Indications: bacterial infection in otitis externa
Cautions: - avoid prolong use.
Contraindications: - perforated tympanic membrane (see also notes above)
Side effects: local sensitivity
Dose and Administration
Ear, apply 3 - 4 drops 3 - 4 times daily; reduce frequency when relief obtained.
Hydrogen peroxide
Solution, 3 %
Hydrogen peroxide is an oxidizing agent with antiseptic, disinfectant, and deodorant properties. It is used in dilute aqueous solution for cleansing wounds.
Storage: - at room temperature in airtight container. Solutions should not be stored for long periods. Those not containing a stabilizer should be stored at a temperature not exceeding 15°C. Protect from light.
Oxytetracycline Hydrochloride + Hydrocortisone Acetate + polymyxin B sulphate
Suspension (ear drop) 4 mg +15 mg + 10,000 units in each ml.
Indications: - bacterial infection with eczematous inflammation in otitis external (see also notes above).
Caution: avoid prolonged use
Contraindications: perforated tympanic membrane.
Side effects: - local sensitivity reactions
