Gentamicin + Hydrocortisone Acetate

Approved indications

• Acute and chronic external ear infections (otitis externa) caused by susceptible bacteria, including Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli.
• Inflammatory conditions of the external ear accompanied by bacterial infection, such as eczema or dermatitis of the external ear canal.

Clinically accepted / off-label uses

• Superficial skin infections where combination topical antibiotic and corticosteroid therapy is appropriate.
• Post-aural surgery prophylaxis for localized infection and inflammation under specialist guidance.

Adults and children ≥2 years

• Otitis externa: Instill 3–4 drops into the affected ear 2–3 times daily for 7–10 days, or as prescribed by a healthcare professional.
• Avoid contamination of the dropper; do not touch the ear canal with the tip.
• Tilt head to allow solution to reach the canal; remain in this position for a few minutes.

Pediatrics (<2 years)

• Use only under medical supervision; dosing and safety data are limited.

Special populations

• Renal impairment: Systemic absorption is minimal; routine adjustment not required for topical use.
• Hepatic impairment: No dose adjustment required.

Administration precautions

• Do not use if tympanic membrane is perforated unless directed by a physician.
• Avoid contact with eyes; rinse immediately if accidental exposure occurs.

• Gentamicin is an aminoglycoside antibiotic that binds irreversibly to the 30S ribosomal subunit of bacteria, inhibiting protein synthesis, causing defective bacterial proteins, and ultimately leading to cell death. It exhibits bactericidal activity against aerobic gram-negative organisms and some gram-positive bacteria.
• Hydrocortisone acetate is a corticosteroid that reduces inflammation, edema, and itching by suppressing the release of pro-inflammatory mediators and inhibiting leukocyte infiltration at the site of infection.
• The combination provides simultaneous antimicrobial activity and anti-inflammatory effect, enhancing symptom relief and healing in infected and inflamed ear canals.

• Absorption: Minimal systemic absorption via intact skin or ear canal; negligible when tympanic membrane is intact.
• Distribution: Limited to local tissues; systemic levels are typically undetectable.
• Metabolism: Hydrocortisone acetate is locally hydrolyzed to hydrocortisone; systemic metabolism occurs in the liver.
• Elimination: Gentamicin absorbed in small amounts is excreted unchanged by the kidneys. Hydrocortisone metabolites are excreted primarily in urine.
• Half-life: Not clinically significant systemically due to minimal absorption.

• Pregnancy: Topical use considered low risk; systemic absorption is minimal. Use only if clearly needed.
• Lactation: Minimal systemic absorption; generally considered safe, but avoid direct contact with the infant.

• Primary class: Topical combination antibiotic and corticosteroid
• Subclass: Aminoglycoside antibiotic + corticosteroid

• Known hypersensitivity to gentamicin, hydrocortisone, or any excipients.
• Viral, fungal, or mycobacterial ear infections without appropriate therapy.
• Perforated tympanic membrane unless specifically directed by a healthcare professional.
• History of aminoglycoside-induced ototoxicity or nephrotoxicity.

• Ototoxicity and nephrotoxicity: Rare with topical use, but caution in patients with tympanic membrane perforation.
• Hypersensitivity reactions: Discontinue if rash, itching, or swelling occurs.
• Prolonged use: Avoid long-term therapy to prevent fungal overgrowth or secondary infection.
• Monitoring: Inspect the ear canal for signs of persistent infection or worsening symptoms; discontinue if no improvement in 7–10 days.

Common

• Local burning, stinging, or itching at the site of application.
• Mild transient redness or irritation.

Serious / rare

• Allergic reactions: rash, hives, swelling.
• Secondary fungal or bacterial superinfections.
• Rare systemic effects due to absorption in patients with tympanic membrane perforation, including nephrotoxicity or ototoxicity.

Timing

• Local effects usually appear within the first few applications.
• Serious reactions are rare and may develop during prolonged use.

• Minimal systemic interactions due to low absorption.
• Caution with other ototoxic or nephrotoxic drugs if applied to a perforated tympanic membrane.
• Avoid simultaneous use with other topical ear medications unless prescribed.

• Short-course therapy (7–10 days) preferred to reduce risk of resistance and adverse effects.
• Avoid routine use in tympanic membrane perforation without specialist supervision.
• Monitor for persistent infection; discontinue if no improvement to prevent secondary complications.

• Store at 20°C to 25°C (68°F to 77°F).
• Protect from light and moisture.
• Keep the bottle tightly closed when not in use.
• Do not freeze.
• Keep out of reach of children.