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Topical Aminoglycoside — Otitis Externa

Gentamicin Ear Drops

Brand names: Genticin Ear Drops, Cidomycin

Used in: Acute Appendicitis

Gentamicin ear drops are a topical aminoglycoside antibiotic preparation, often combined with a corticosteroid, used to treat bacterial infections of the outer ear (otitis externa).

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

Clinical monograph

How it works

Gentamicin binds irreversibly to the bacterial 30S ribosomal subunit, inhibiting protein synthesis and producing a bactericidal effect against many Gram-negative organisms.

Prescribing in practice

  • Aminoglycoside ear drops are potentially ototoxic and should be avoided where the tympanic membrane is perforated, as access to the middle ear risks vestibular and cochlear damage.
  • Reserved for use when the eardrum is known to be intact unless a specialist judges the benefit to outweigh the ototoxicity risk.
  • Prolonged or repeated courses may encourage fungal or resistant bacterial superinfection of the ear canal.

Monitoring

Monitor for resolution of infection and for any new hearing loss, tinnitus or vertigo, which warrant immediate discontinuation and review.

Counselling the patient

  • Tell us straight away if you notice any change in hearing, ringing in the ears, or dizziness.
  • Stop using the drops and seek advice if symptoms worsen or fail to settle.
  • Use only for the duration advised and do not continue beyond the recommended course.

Evidence & guidelines

Use is guided by NICE and MHRA advice on the ototoxicity risk of topical aminoglycosides in the presence of a perforated eardrum.

Reference: NICE CKS Otitis Externa; ENT-UK CSOM Guidelines; BSO Menière's Disease Guidelines; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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