Drugs List

Therapeutic Indications

Uses

Eye infection - topical treatment
Ocular prophylaxis after trauma
Otitis externa - infective
Prophylaxis against otitis externa following trauma

Contraindications

Myasthenia gravis
Perforated tympanic membrane

Precautions and Warnings

Elderly
Soft contact lenses
Breastfeeding
Hepatic impairment
Known or suspected mitochondrial disorder
Pregnancy
Renal impairment

Do not use if tympanostomy tube (grommet) is in situ
Exclude tympanic membrane perforation before initiating treatment
Advise patient blurred vision may affect ability to drive/operate machinery
Contains benzalkonium chloride
Avoid contact with middle ear
In combined therapy, administer eye products at least five minutes apart
To reduce systemic absorption compress lacrimal sac during administration
Advise patient to report signs of deafness
Possible ototoxicity when used at high doses in susceptible groups
Possible systemic absorption
Discontinue if irritation or sensitisation occur
Discontinue if superinfection occurs
Avoid long term use
Advise patient to avoid touching the eye/other surfaces with container tip
Remove contact lenses before use and re-insert 15 minutes after use

When used in the ears clean the area before use.

Serious adverse reactions including neurotoxicity, ototoxicity and nephrotoxicity have occurred in patients receiving systemic gentamicin therapy. Although these effects have not been reported following topical otic use of gentamicin, caution is advised when used concomitantly with systemic aminoglycosides.

Severe infections may require a concurrent systemic antibiotic regime.

It must be established whether the patient has a known mitochondrial disorder or a family history of ototoxicity before use.

There have been reports of cases of an increased risk of ototoxicity with aminoglycosides administered to patients with mitochondrial mutations, including cases where the patient's aminoglycoside serum levels were within the recommended range. No cases were identified with topical preparations, however there is a potential risk with gentamicin and other aminoglycosides administered at the site of toxicity.

The use of aminoglycoside treatment versus alternative options in patients with susceptible mutations should be considered. Genetic testing should also be considered especially in patients requiring recurrent or long term treatment with aminoglycosides; however urgent treatment should not be delayed. To minimise the risks of adverse effects, continuous monitoring of renal and auditory function, as well as hepatic and laboratory parameters, is recommended for all patients.

Avoid application to open wounds or damaged skin as systemic absorption can cause irreversible partial or total deafness. This effect is enhanced in patients with renal or hepatic impairment and the elderly.

Direct contact of gentamicin with the middle and inner ear can result in irreversible toxic effects and any benefits need to be considered against the risk of infection itself causing hearing loss.

Use with caution in an inflamed eye as increased systemic absorption may occur through the conjunctiva.

Use with caution in dry eye patients and in patients where the cornea may be compromised.

Pregnancy and Lactation

Pregnancy

Use gentamicin with caution during pregnancy.

The manufacturer recommends that gentamicin should only be used in pregnancy when considered essential by the physician, after careful assessment of the potential risks and benefits.

Schaefer (2015) concludes that aminoglycosides may be administered locally because systemic absorption is minimal.

Lactation

Use gentamicin with caution during breastfeeding.

The manufacturer recommends that gentamicin should only be used in breastfeeding when considered essential by the physician, after careful assessment of the potential risks and benefits.

Lactmed states that maternal use of an ear drop or eye drop that contains gentamicin presents little or no risk for the nursing infant.

Side Effects

Blurred vision (transient)
Burning sensation (local)
Dermatitis
Hypersensitivity reactions
Irritation (localised)
Itching sensation (local)
Stinging (transient)
Superinfections
Systemic effects

Presentation

Eye and Ear drops containing gentamicin sulfate.

Drugs List

Therapeutic Indications

Uses

Eye infection - topical treatment
Ocular prophylaxis after trauma
Otitis externa - infective
Prophylaxis against otitis externa following trauma

Dosage

Adults

Children

Additional Dosage Information

Contraindications

Myasthenia gravis
Perforated tympanic membrane

Precautions and Warnings

Elderly
Soft contact lenses
Breastfeeding
Hepatic impairment
Known or suspected mitochondrial disorder
Pregnancy
Renal impairment

Do not use if tympanostomy tube (grommet) is in situ
Exclude tympanic membrane perforation before initiating treatment
Advise patient blurred vision may affect ability to drive/operate machinery
Contains benzalkonium chloride
Avoid contact with middle ear
In combined therapy, administer eye products at least five minutes apart
To reduce systemic absorption compress lacrimal sac during administration
Advise patient to report signs of deafness
Possible ototoxicity when used at high doses in susceptible groups
Possible systemic absorption
Discontinue if irritation or sensitisation occur
Discontinue if superinfection occurs
Avoid long term use
Advise patient to avoid touching the eye/other surfaces with container tip
Remove contact lenses before use and re-insert 15 minutes after use

When used in the ears clean the area before use.

Serious adverse reactions including neurotoxicity, ototoxicity and nephrotoxicity have occurred in patients receiving systemic gentamicin therapy. Although these effects have not been reported following topical otic use of gentamicin, caution is advised when used concomitantly with systemic aminoglycosides.

Severe infections may require a concurrent systemic antibiotic regime.

It must be established whether the patient has a known mitochondrial disorder or a family history of ototoxicity before use.

There have been reports of cases of an increased risk of ototoxicity with aminoglycosides administered to patients with mitochondrial mutations, including cases where the patient's aminoglycoside serum levels were within the recommended range. No cases were identified with topical preparations, however there is a potential risk with gentamicin and other aminoglycosides administered at the site of toxicity.

The use of aminoglycoside treatment versus alternative options in patients with susceptible mutations should be considered. Genetic testing should also be considered especially in patients requiring recurrent or long term treatment with aminoglycosides; however urgent treatment should not be delayed. To minimise the risks of adverse effects, continuous monitoring of renal and auditory function, as well as hepatic and laboratory parameters, is recommended for all patients.

Avoid application to open wounds or damaged skin as systemic absorption can cause irreversible partial or total deafness. This effect is enhanced in patients with renal or hepatic impairment and the elderly.

Direct contact of gentamicin with the middle and inner ear can result in irreversible toxic effects and any benefits need to be considered against the risk of infection itself causing hearing loss.

Use with caution in an inflamed eye as increased systemic absorption may occur through the conjunctiva.

Use with caution in dry eye patients and in patients where the cornea may be compromised.

Pregnancy and Lactation

Pregnancy

Use gentamicin with caution during pregnancy.

The manufacturer recommends that gentamicin should only be used in pregnancy when considered essential by the physician, after careful assessment of the potential risks and benefits.

Schaefer (2015) concludes that aminoglycosides may be administered locally because systemic absorption is minimal.

Lactation

Use gentamicin with caution during breastfeeding.

The manufacturer recommends that gentamicin should only be used in breastfeeding when considered essential by the physician, after careful assessment of the potential risks and benefits.

Lactmed states that maternal use of an ear drop or eye drop that contains gentamicin presents little or no risk for the nursing infant.

Side Effects

Blurred vision (transient)
Burning sensation (local)
Dermatitis
Hypersensitivity reactions
Irritation (localised)
Itching sensation (local)
Stinging (transient)
Superinfections
Systemic effects

Overdosage

It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

The following number will direct the caller to the relevant local centre (0844) 892 0111

Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( www.toxbase.org ) or if this is unavailable at the backup site ( www.toxbasebackup.org ).

Further Information

Last Full Review Date: August 2022

Reference Sources

Drugs During Pregnancy and Lactation: Treatment Options and Risk Assessment, 3rd edition (2015) ed. Schaefer, C., Peters, P. and Miller, R. Elsevier, London.

Summary of Product Characteristics: Genticin Eye/Ear drops. ADVANZ Pharma. Revised May 2021.

NICE Evidence Services Available at: www.nice.org.uk Last accessed: 21 July 2022.

US National Library of Medicine. Toxicology Data Network. Drugs and Lactation Database (LactMed).
Available at: https://www.ncbi.nlm.nih.gov/books/NBK501922/
gentamicin Last revised: 16 August 2021
Last accessed: 21 July 2022