Kanamycin

Approved Indications:

• Bacterial Conjunctivitis:
  Treatment of acute or chronic conjunctival infections caused by kanamycin-sensitive Gram-negative and some Gram-positive bacteria.
• Blepharitis and Blepharoconjunctivitis:
  For lid margin and conjunctival infections due to susceptible organisms.
• Superficial Ocular Infections:
  As adjunct therapy for bacterial keratitis or corneal abrasions caused by susceptible organisms.

Important Off-label / Clinically Accepted Uses:

• Post-surgical prophylaxis:
  Short-term use after ocular surgery (e.g., cataract or pterygium removal) to prevent secondary bacterial infection.
• Pediatric conjunctivitis:
  Infections in children caused by sensitive bacteria when other treatments are unsuitable.

Adults and Children (≥1 year):

• Mild to moderate infections: Instill 1–2 drops into the affected eye(s) every 4–6 hours.
• Severe infections: Instill 1–2 drops every 1–2 hours during the initial 24–48 hours, then taper as symptoms improve.
• Typical treatment duration: 5–7 days.

Infants (<1 year):

• Use only under specialist guidance; safety data limited. Start with lowest frequency (e.g., every 8–12 hours).

Elderly:

• No dosage adjustment necessary; monitor for increased ocular sensitivity.

Administration Guidelines:

• Wash hands before and after use.
• Do not touch the dropper tip to any surface.
• Wait at least 5–10 minutes before applying other eye medications.
• Contact lenses should be removed before instillation and may be reinserted after 15 minutes.

Kanamycin is an aminoglycoside antibiotic that binds to the 30S ribosomal subunit of susceptible bacteria. This binding disrupts the initiation of protein synthesis and leads to the incorporation of incorrect amino acids, resulting in defective and nonfunctional proteins. The drug is bactericidal, leading to cell death. When used ophthalmically, kanamycin acts directly at the site of infection on the conjunctiva and cornea.

• Absorption: Minimal systemic absorption through ocular tissues; drug action is local.
• Onset of Action: Symptomatic relief often begins within 24–48 hours of initiation.
• Distribution: Confined to conjunctival and corneal tissues.
• Metabolism: Not metabolized locally.
• Elimination: Any absorbed amount is eliminated unchanged via the kidneys.
• Systemic Exposure: Negligible in healthy adults with intact ocular barriers.

• Pregnancy:
• Topical kanamycin has minimal systemic absorption.
• Although systemic use is Category D, ophthalmic use is generally considered low risk when clearly needed.
• Lactation:
• Insignificant levels absorbed or secreted into breast milk when used topically.
• Safe for nursing mothers under ophthalmologist supervision.

• Class: Ophthalmic antibiotic
• Subclass: Aminoglycoside, bactericidal

• Known hypersensitivity to kanamycin, other aminoglycosides, or any component of the formulation
• Known or suspected viral or fungal eye infections
• Presence of punctal plug or nasolacrimal obstruction (may increase systemic absorption risk)

• Allergic reactions: Discontinue if irritation, swelling, or rash occurs.
• Superinfection risk: Prolonged use may result in fungal or resistant bacterial overgrowth.
• Corneal toxicity: Rare, but possible with long-term or frequent use.
• Use in pediatric patients <1 year: Only under ophthalmologist supervision.
• Do not wear contact lenses during active infection.

Common (localized):

• Mild conjunctival redness or irritation
• Temporary blurred vision after instillation
• Increased tear production

Uncommon:

• Eyelid swelling
• Photophobia
• Ocular dryness

Rare/Serious:

• Hypersensitivity reaction (swelling, pruritus, rash)
• Superinfection (e.g., fungal keratitis)
• Corneal ulceration with long-term use
• Transient burning or stinging 

• sensation

• Topical ophthalmic agents: If used concurrently with other drops (e.g., steroids or NSAIDs), separate by at least 5–10 minutes.
• Systemic aminoglycosides: Avoid combined use due to cumulative toxicity risk, especially ototoxicity or nephrotoxicity.
• No known food or alcohol interactions due to minimal systemic absorption.

• WHO/TB programs: Kanamycin systemic use in TB has declined due to toxicity; ophthalmic use remains acceptable where indicated.
• No major changes in ophthalmic indications reported in recent updates by global or regional guidelines.
• Emphasis on antimicrobial stewardship encourages limiting use to confirmed or highly suspected bacterial infections only.

• Storage temperature: 15°C to 25°C (59°F to 77°F)
• Protect from light and moisture.
• Do not freeze.
• After opening: Discard within 28 days even if the bottle still contains medication.
• Store in upright position with tightly closed cap.
• Keep out of reach of children.