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12.1 Drugs acting on the ear

12.1.1 Otitis externa

Anti-inflammatory preparations
Acetic acid 2% (Ear Calm)
Aluminium Acetate 8% ear drops 
Betamethasone sodium phosphate drops
Ciprofloxacin + dexamethasone drops – see note
Dexamethasone + framycetin + gramicidin ((Sofradex) drops
Dexamethasone + neomycin + glacial acetic acid (Otomize Ear spray)
Hydrocortisone + gentamicin drops (Gentisone HC)
Prednisolone Sodium Phosphate 0.5%
Glycerine and Ichthammol application


Anti-infective preparations
Clotrimazole solution
Gentamicin drops


1. Chloramphenicol ear drops have been removed from the formulary on cost effective grounds. A CKS review on acute otitis externa did not recommend chloramphenicol ear drops, as they contain propylene glycol which causes contact dermatitis in about 10% of people. Chloramphenicol is significantly more expensive than other products listed on the formulary (link to CKS review

2. Ciprofloxacin + dexamethasone ear drops are the only available licensed quinolone/steroid combination ear drop which can be safely used in acute or acute on chronic suppurative otitis media where there is a perforated tympanic membrane or where grommets are in-situ. Aminoglycosides e.g. Sofradex, Gentisone HC are potentially ototoxic, whereas ciprofloxacin does not share this property.

3. The acute form of otitis externa can be painful, but may be present as irritation of the ear canal, without discharge or deafness. The entrance to the canal may be excoriated from scratching. The canal is swollen and narrowed and it contains debris not unlike wet blotting paper. Although antibiotics are frequently used with apparent success for this problem the aetiological role of microbes is not established.

It seems that a vicious circle of irritation, excoriation, wetness, colonisation, inflammation, debris formation, blockage, interference and further irritation is set up. It is essential both to treat the swelling of the canal and remove the debris from within the canal from the outset otherwise antibiotic drops, if prescribed, cannot even reach the targeted microbes. These two factors are more likely to be the causes of failure to respond rather than antibiotic resistance and thus a swab is unhelpful in achieving a cure.

If ear swabs are taken, they frequently demonstrate an overgrowth of pseudomonas, but this rarely indicates the presence of the more serious 'malignant' otitis externa which should be suspected in diabetic or debilitated patients, rather than otherwise healthy adults.

The canal swelling can be improved by the use of topical steroid, either introduced into the outer canal on a small piece of half inch ribbon gauze, or painted onto the canal with a fine wool applicator. Over a couple of days the swelling may be sufficiently reduced to then remove some of the debris, again with a fine wool carrier and good illumination.

Cleaning the debris from the canal is far more effective than the recurrent application of drops. In difficult cases, this is most satisfactorily achieved with the use of a microscope and fine suction in the ENT department. Thus referral should be considered for those patients who present with severe pain and canals so swollen that it is difficult to introduce steroid or drops into the canal or those who fail to respond to the simple measures outlined above, who often have debris which is difficult to remove, deep in the canal.

Otitis externa may be caused initially by the canal skin becoming moist, so, it is worth considering that the further addition of moisture in the form of ear drops may exacerbate the situation. Thus the application of steroid and antibiotic in ointment form may be advantageous.

Advice for avoiding future recurrent infections may be useful. In particular avoidance of getting water in the ear, if this does happen it should be shaken out rather than introducing the corner of a towel or other objects into the canal. For itchy ears or those with an element of eczema of the pinna, a small amount of topical weak steroid may help reduce the itching and hence the possibility of re-infection from scratching fingers.

Cotton wool in the ears during a hair-cut will prevent hair trimmings, which can be very irritative entering the deep canal.


12.1.3 Removal of ear wax

Olive oil drops
Sodium bicarbonate drops


1. Wax should only be removed if it causes deafness or interferes with viewing of the eardrum. Syringing should be avoided where there is a perforated ear drum, previous ear surgery or deafness in the other ear. Sodium bicarbonate drops may be used 2 or 3 times daily for 1-2 weeks before syringing where the wax is impacted. The patient should be advised to lie with the affected ear uppermost for 5-10 minutes after use of the eardrops.

2. Use of sodium bicarbonate drops for up to a month may alleviate the need for syringing altogether. Specialist advice should be sought for difficult cases.

3. Cerumol drops are more likely to cause sensitisation.


For link to BNF section: 12.1 Drugs acting on the ear