Genticin HC 0.3%+1%

INDICATIONS

This preparation is indicated for the treatment of chronic suppurative otitis media, otitis externa and as prophylactic treatment of otitis externa following trauma. This preparation ear drops is also indicated for post-operative local use in surgery to infected mastoid cavities.

PHARMACOLOGY

Gentamicin is an aminoglycoside antibiotic and has a bactericidal action against many Gram-negative and some strains of Gram-positive bacteria. After actively transporting across the bacterial cell membrane, Gentamicin binds to a specific receptor protein on the 30S subunit of bacterial ribosomes, and interferes with an initiation complex between mRNA and the 30S subunit, inhibiting protein synthesis. DNA may be misread, thus producing nonfunctional proteins; polyribosomes are split apart and are unable to synthesize protein. Hydrocortisone depresses formation, release, and activity of endogenous mediators of inflammation as well as modifying immune response.

DOSAGE

For Middle Ear Infection: Instill 2-4 drops in the affected ear three to four times a day and at night, or more frequently if required. The suspension should be warmed by holding the bottle in the hand for one or two minutes to avoid dizziness, which may result from the instillation of a cold suspension. The patient should lie with the affected ear upward, and then the drops should be instilled. The tragus should then be pumped 5 times by pushing inward to facilitate penetration of the drops into the middle ear. This position should be maintained for two minutes. Repeat, if necessary, for the opposite ear. Discard unused portion after therapy is completed.For Ear Canal Infection: Instill 2-4 drops in the affected ear three to four times a day and at night, or more frequently if required. The suspension should be warmed by holding the bottle in the hand for one or two minutes to avoid dizziness, which may result from the instillation of a cold suspension. The patient should lie with the affected ear upward, and then the drops should be instilled. This position should be maintained for two minutes to facilitate penetration of the drops into the ear canal. Repeat, if necessary, for the opposite ear. Discard unused portion after therapy is completed.

INTERACTION

Gentamicin: Additive effect with other neurotoxic and/or nephrotoxic drugs including cephalosporins, methicillin, amphotericin B, ciclosporin, cisplatin, potent diuretics (e.g. ethacrynic acid, furosemide) and neuromuscular blocking agents (e.g. succinylcholine, tubocurarine). May potentiate the effect of anticoagulants (e.g. warfarin, phenindione). May antagonise the effect of neostigmine and pyridostigmine. Increased risk of hypocalcaemia with bisphosphonates. Increased risk of neuromuscular blockade with botulinum toxin. Indometacin may increase the plasma concentration of gentamicin in neonates.Hydrocortisone: Thiazides may enhance hyperglycaemia and hypokalaemia caused by corticosteroids. Increased incidence of peptic ulcer or Gl bleeding with concurrent NSAIDs admin. Response to anticoagulants altered. Dose of antidiabetics and antihypertensives needs to be increased. Decreases serum cone of salicylates and antimuscarinic agents. Ethanol may enhance gastric mucosal irritation. Reduced efficacy with concurrent use of carbamazepine, phenytoin, primidone, barbiturates and rifampicin. Mutual inhibition of metabolism between ciclosporin and corticosteroids increase plasma cone of both drugs. Enhanced effect in women taking oestrogens or oral contraceptives.

SIDE EFFECTS

Ear discomfort, ear irritation may occur in rare cases. Gentamicin may cause irreversible partial or total deafness when given systemically or when applied topically to open wounds or damaged skin.

PREGNANCY & LACTATION

Pregnancy: No adequate and well controlled studies have been performed in pregnant women. Topical administration of any corticosteroid to pregnant animals can cause abnormalities of foetal development. Caution should be exercised when this Ear Drops is used by a pregnant woman.Nursing Mothers: This Ear Drops should be administered to a nursing woman only after careful assessment of the potential risks and benefits.

PRECAUTIONS & WARNINGS

This Ear Drops should be discontinued at the first appearance of any sign of local or general hypersensitivity. Long-term continuous therapy should be avoided. Prolonged use may result in overgrowth of non-susceptible organisms, including fungi. If an infection is not improved after one week, cultures and susceptibility tests should be performed to verify the identity of the organism and to determine what alternative therapy should be installed. In severe infections, this Ear Drops should be supplemented with appropriate systemic antibiotic treatment.

THERAPEUTIC CLASS

Hydrocortisone & Combined preparations, Ophthalmic steroid - antibiotic combined preparations

STORAGE CONDITIONS

Store in a cool and dry place. Protect from light and freezing. Discard contents one month after opening.