Topical Aminoglycoside — Otitis Externa Pregnancy: Avoid if possible — aminoglycoside ototoxicity risk; topical use with intact TM has minimal systemic absorption

Gentamicin Ear Drops

Brand names: Genticin Ear Drops, Cidomycin

Adult dose

Dose: 2–4 drops

Route: Otic

Frequency: Three to four times daily

Max: 4 drops per ear four times daily

Topical aminoglycoside antibiotic for chronic suppurative otitis media (CSOM) and otitis externa. CONTRAINDICATED with tympanic membrane perforation — risk of sensorineural hearing loss (cochlear toxicity via round window absorption).

Paediatric dose

Dose: 2–3 drops drops/kg

Route: Otic

Frequency: Three times daily

Max: 3 drops per ear three times daily

BNFc: use only under specialist supervision in children with intact tympanic membrane. AVOID in perforation — ototoxicity risk.

Dose adjustments

Renal

No systemic dose adjustment required (topical); however, systemic absorption can occur with perforated TM — avoid in renal impairment with perforated TM

Hepatic

No dose adjustment required

Paediatric weight-based calculator

Patient weight (kg)

BNFc: use only under specialist supervision in children with intact tympanic membrane. AVOID in perforation — ototoxicity risk.

Clinical pearls

CONTRAINDICATED with tympanic membrane perforation — aminoglycosides absorbed via round window → cochlear hair cell death → permanent sensorineural hearing loss
CSOM with perforation: use topical quinolone (ciprofloxacin ear drops/Ciloxan) which is safe with perforation — preferred by NICE and ENT-UK
Genticin (gentamicin 0.3%) available alone or combined with hydrocortisone (Gentisone HC) for combined antibacterial and anti-inflammatory action
Annual audiology recommended for patients on long-term topical aminoglycosides
Middle ear irrigation with gentamicin solution (intratympanic gentamicin) is used therapeutically for Menière's disease — chemical labyrinthectomy to ablate vestibular function; deliberate vestibulotoxicity

Contraindications

Perforated tympanic membrane — CONTRAINDICATED (ototoxicity)
Aminoglycoside hypersensitivity

Side effects

Sensorineural hearing loss (permanent — with perforated TM)
Vestibular toxicity
Local irritation

Interactions

Systemic aminoglycosides — additive ototoxicity risk

Monitoring

Audiometry (if prolonged use)
Symptom response
Tympanic membrane integrity before prescribing

Reference: BNFc; BNF 90; BNFc; NICE CKS Otitis Externa; ENT-UK CSOM Guidelines; BSO Menière's Disease Guidelines. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways