Lexacin (Levofloxacin Hemihydrate)

Lexacin (levofloxacin) is a fluoroquinolone antibiotic indicated for bacterial infections affecting the ocular surface and cornea, providing broad‑spectrum activity against common Gram‑negative and Gram‑positive pathogens.

• Bacterial conjunctivitis: eliminates susceptible bacteria, leading to rapid reduction of ocular discharge, redness, irritation, and promotes faster symptom resolution.
• Keratitis: targets bacterial pathogens in the corneal stroma, aiding re‑epithelialisation, decreasing infiltrate size, and helping restore visual clarity.
• Corneal ulcer: combats infection within the ulcerated corneal tissue, supporting tissue repair, reducing risk of scarring or perforation, and preserving vision.

• Levofloxacin exerts its antibacterial effect by inhibiting bacterial DNA gyrase (topoisomerase II) and topoisomerase IV, enzymes essential for DNA supercoiling and replication. By binding to these enzymes, it prevents DNA unwinding and transcription, leading to bacterial cell death. The drug displays concentration‑dependent bactericidal activity against a broad range of Gram‑negative and Gram‑positive ocular pathogens. In the eye, the drug penetrates the corneal epithelium and achieves therapeutic concentrations in the aqueous humor.

Levofloxacin ophthalmic solution may cause ocular and systemic adverse reactions, which are categorized by frequency and severity.

Common Side Effects

• Eye irritation: transient burning, stinging, or foreign‑body sensation often occurring immediately after drop administration.
• Redness: mild conjunctival hyperemia that usually resolves without treatment and is generally self‑limiting.
• Blurred vision: temporary visual disturbance typically lasting a few minutes after instillation.

Serious or Rare Side Effects

• Corneal ulceration: worsening of existing corneal lesions or development of new ulcerative areas, requiring prompt immediate medical attention.
• Severe allergic reaction: systemic signs such as swelling, rash, urticaria, or anaphylaxis that may necessitate discontinuation.
• Tendon rupture: rare systemic tendon injury, most commonly affecting the Achilles tendon, reported rarely with fluoroquinolones.

When using Lexacin, clinicians should observe specific precautions to ensure safety and maintain product efficacy.

• Allergy assessment: verify patient has no known hypersensitivity to fluoroquinolones or levofloxacin.
• Contact lens use: advise removal of contact lenses before and after instillation to avoid drug interaction.
• Concurrent ocular infection: avoid use if viral or fungal eye infection is suspected, as antibacterial therapy will not be effective.
• Systemic conditions: exercise caution in patients with a history of tendon disorders or neuropathy.
• Pregnancy and lactation: use only if the potential benefit outweighs the risk, after professional evaluation.
• Store at ambient temperature: keep the product below 25 °C in the original container, protected from light and moisture.

Levofloxacin may interact with other ophthalmic or systemic agents; notable interactions are classified by clinical significance.

Major Interactions (Avoid)

• Systemic fluoroquinolones: concurrent systemic use can increase risk of tendon toxicity.
• Corticosteroid eye drops: may reduce antibacterial efficacy and increase risk of secondary infection.
• Anticholinergic agents: may potentiate ocular dryness when combined with levofloxacin drops.

Moderate Interactions (Monitor Closely)

• Non‑steroidal anti‑inflammatory drugs (NSAIDs): monitor for delayed wound healing.
• Herbal supplements containing quinine: may enhance systemic fluoroquinolone exposure.
• Warfarin: monitor INR as levofloxacin can potentiate anticoagulant effect.