inflammatory diseases of middle ear cavity causes a certain amount of
fibrosis preventing adequate concentrations of systemically
administered drug reaching it.
drops are solutions / suspensions of medicines in solvents like water,
glycerol, diluted alcohol, or propylene glycol. These solutions can be
instilled into the ear. For these ear drops to be effective sufficient
contact time should be provided.
Indications for use of topical ear drops:
Bacterial / fungal infections of external auditory canal
Chronic suppurative otitis media with a large drum perforation
To liquefy accumulated wax in the external auditory canal
drops are to reach the middle ear in adequate concentration the ear
drum perforation should be fairly large. The method of administration
of ear drops to reach the middle ear cavity is known as the
displacement method. In this method the external ear is made dependent
by turning the head to the opposite side, with the chin touching the
shoulder. The external auditory canal is filled with ear drops.
Pressure is applied to the external ear by alternate pressing of the
tragus. This maneuver displaces the air from the middle ear cavity
which is duly filled up by the ear drops.
Difference between solution and solvent ear drops:
usually consists of a drug which is dissolved in a solvent where as
suspension consists of an insoluble drug distributed in a liquid
medium. Some of the ear drops can be used as eye drops also. To
facilitate such multi usage certain adjuvant drugs are added to the
drops in addition to the active drug. Commonly used adjuvants in such
drops which can be used as eye and ear drops include:
0.01% Benzalkonium chloride – This acts as an antifungal agent
metabisulphite – This agent acts as a buffer maintaining the pH of the
solution. This strict maintenance of pH prevents easy degradation of
the active drug molecule present in the drops. It also minimizes the
irritation caused due to application of the drops. It also retards the
oxidation of the active drug there by prolonging the effect of the
edetate – This is another adjuvant commonly used. It also acts as an
excellent buffering agent. This adjuvant drug increases the
bactericidal and antifungal activity of Benzalkonium chloride.
Steroids – Beclamethazone is the commonly used steroid adjuvant drug in the ear drops for its antiinflammatory effect.
of the local drug preparations to be used in the external auditory
canal may be in the form of creams / ointments. These ointments usually
contain antibiotics and antiinflammatory agents in a suitable base like
liquid paraffin, wool fat, yellow soft paraffin. Ointments usually have
paraffin base. Ointaments are very useful in managing dry scaly skin
conditions of external auditory canal. Ointment preparations with
Lanolin as the base (wool fat) should be marked clearly on the tube
because some patients may develop hypersensitivity reaction to this
component of the medicine.
acid ear drops – Acetic acid in concentration of 2% is an excellent
antibacterial and antifungal agent. Acetic acid ear drops can be used
to treat mild otitis externa. This is commonly used in paediatric age
acetate ear drops: This is an astringent drug which can be administered
as ear drops or by dipping a cotton wick in the drug and inserting the
same into the external auditory canal. Astringent belongs to a group of
medicine that causes shrinkage of tissue on local application.
Shrinkage of tissue is caused due to the hydroscopic effect of the
drug. Hence it can be used to reduce oedema involving the external
auditory canal. If this drug needs to be used for its astringent effect
then it should be administered using a cotton wick. This drug is known
to cause deposition of aluminium acetate crystals in the external
auditory canal. Hence periodic cleansing of the ear is a must when this
drug is used. This drug can be safely used even in pregnant mothers. In
fact this is safest drug that can be administered during pergnancy.
acid ear drops: Formerly this drug was used for their bacteriostatic
and antifungal efects. It can be used in varying concentrations. Maxium
concentration that can be safely used is 5%. This drug gets absorbed
via the inflammed skin leading on to systemic toxicity due to the drug.
Antibiotic & steroid ear drops:
/ prednisolone sodium phosphate can be administered along with
antibiotics like gentamycin / neomycin / quinolenes. When used in
combination with these antibiotics they faciliate better effects due to
their antiinflammatory effects.
Clotrimazole ear drops:
is a broad spectrum antifungal agent. This drug inhibits ergosterol
synthesis by the fungal cell wall. This destroys the fungus. Fungal
infections involving the external auditory canal can also be caused due
to inappropriate use of steroid ear drops. Administration of
clotrimazole can cause burning sensation in the external auditory
canal. Patient should be advised to tolerate it.
Ceruminolytic ear drops:
are the most commonly used ear drops. Drugs belonging to this group
include oil / aqueous preparations. These drugs are known to soften the
wax facilitating its removal by aural syringing. 0.9% sodium choloride
solution can be used as ceruminolytic agent. 5% sodabicarb solution can
also be used as ceruminolytic agent.
Olive oil / coconut oil / liquid paraffin can also be used as ceruminolytic agents.
Organic solvents like chlorbutanol / paradichlorobenzene can also be used as solvents, but may cause irritation to meatal skin.
Indications for administration for systemic antibiotics:
Acute otitis media
Furunculosis of external auditory canal
Perichondritis of pinna
Malignant otitis externa
Drugs administered systemically include:
Drugs used in the management of vertigo:
can be used in the management vertigo associated with meniere's
disease. This drug reduces the endolymph pressure by improving
microvascular circulation in the striavascularis of the cochlea. It
also reduces the vertigenous sensation by inhibiting the firing rate of
vestibular nuclei. Betahistine is known to reduce vertigo / tinnitus
but does little to improve hearing. It is usually prescribed in doses
of 16 mg thrice a day.
This drug should be used with caution in patients with bronchial asthma / peptic ulcer.
antagonists: Prochlorperazine belongs to this group. Goes by the
popular name Stemetil. It is a dopamine antagonist acting by blocking
the chemoreceptor trigger zone. It is less sedating with fewer
Drugs belonging to this group acts on H1 receptor at the level of
chemoreceptor trigger zone thereby blocking the vomiting centre.
Examples of drugs belonging to this group are cinnarizine and
cyclizine. Cinnarizine can be used as prophylaxis for migraine in doses
of 30 mg three times a day. Cyclizine is useful only during acute
attacks and is given in doses of 50 mg thrice a day.
in the management of meniere's disease: Thiazides and acetazolamide can
be used in the management of acute symptoms of Meniere's disease. The
cause decompression of the endolymphatic sac due to their diuretic
in the treatment of sudden sensorineural hearing loss: Steroids have
been used in the management of sudden sensorineural hearing loss with
varying degress of success. Dosage regimen is as follows:
60 mg on day I
50 mg on day II
40 mg for following three days
30 mg for subsequent three days
Use of antiviral drugs in otology:
is the classic example of drug belonging to this group. It can be
administered in patients with Herpes Zoster oticus. It acts by
inhibiting nucleic acid synthesis. It is administered orally in doses
of 800 mg five times a day for 5 days. If administered within 72 hours
after development of rash it reduces post herpetic neuralgia.
Use of sodium fluroide in otosclerosis:
fluroide is used tto slow down the development of sensorineural hearing
loss in a patient with otospongiosis. It acts due to its enzyme
inhibiting activity there by preventing osteoclastic bone resorption.
Usually it is administered in doses of 40 mg per day for a period of
3-6 weeks. This drug is really useful in patients with cochlear
otosclerosis. It has propensity to cause gastric irritation and renal