Ketorolac (0.5% w/v) + Moxifloxacin (0.5% w/v)

Clinical Pharmacologist's Monograph

⚠️ Prescription Only: This medicine is Schedule H/H1. Do not self-medicate.

1. Clinical Overview

A fixed-dose combination ophthalmic solution containing a non-steroidal anti-inflammatory drug (NSAID) and a fourth-generation fluoroquinolone antibiotic. It is designed for the management of post-operative ocular inflammation and prevention/treatment of associated bacterial infections following cataract surgery. This combination leverages the anti-inflammatory and analgesic action of Ketorolac with the broad-spectrum bactericidal action of Moxifloxacin.

OnsetDurationBioavailability
Ketorolac: Anti-inflammatory effect begins within 1-2 hours. Moxifloxacin: Bactericidal action begins rapidly upon contact with susceptible bacteria.Ketorolac: Topical effect lasts approximately 4-6 hours per dose. Moxifloxacin: Dosing frequency maintains therapeutic levels in ocular tissues.Topical ocular bioavailability is low (<5% for each agent) due to minimal systemic absorption from the eye, but achieves high local tissue concentrations.

2. Mechanism of Action

The combination exerts a dual action: Ketorolac inhibits the cyclooxygenase (COX) enzymes, primarily COX-1 and COX-2, thereby reducing the synthesis of prostaglandins (mediators of pain, inflammation, and miosis). Moxifloxacin inhibits bacterial DNA gyrase (Topoisomerase II) and topoisomerase IV, enzymes critical for DNA replication, transcription, and repair, leading to rapid bacterial cell death.

3. Indications & Uses

  • Prophylaxis and treatment of post-operative ocular inflammation and pain following cataract surgery
  • Prophylaxis and treatment of post-operative ocular bacterial infections following cataract surgery

4. Dosage & Administration

Adult Dosage: One drop instilled into the conjunctival sac of the affected eye(s) 4 times daily, starting 24 hours post-surgery. Duration: Typically 2 weeks, or as directed by the ophthalmologist.

Administration: 1. Wash hands. 2. Tilt head back. 3. Gently pull lower eyelid to form a pouch. 4. Instill one drop without touching the dropper tip to eye or any surface. 5. Close eyes gently for 1-2 minutes, applying gentle pressure to the nasolacrimal duct (inner corner of eye) to minimize systemic absorption. 6. Wait at least 5 minutes before instilling any other ophthalmic medication.

5. Side Effects

Common side effects may include:

  • Transient ocular burning/stinging on instillation (up to 20%)
  • Superficial punctate keratitis
  • Conjunctival hyperemia
  • Ocular irritation/itching
  • Watery eyes
  • Blurred vision immediately after instillation

6. Drug Interactions

DrugEffectSeverity
Oral Anticoagulants (Warfarin, Acenocoumarol)Increased risk of ocular and systemic bleeding due to additive antiplatelet effect of Ketorolac.Major
Other Systemic NSAIDs (e.g., Aspirin, Ibuprofen, Diclofenac)Increased risk of GI ulceration/bleeding and renal toxicity. Additive antiplatelet effect.Major
Corticosteroids (Oral or Topical)Increased risk of corneal melting, delayed healing, and elevated IOP. Also increased risk of GI ulceration.Major
Antiplatelet drugs (Clopidogrel, Ticagrelor)Increased bleeding risk.Moderate
Antihypertensives (ACE inhibitors, ARBs, Diuretics)NSAID may reduce antihypertensive efficacy and worsen renal function.Moderate
MethotrexateIncreased risk of methotrexate toxicity.Major
ProbenecidMay increase systemic levels of Ketorolac.Moderate
Cation-containing products (Zinc, Iron, Calcium, Antacids)May chelate Moxifloxacin if administered systemically, reducing absorption. Not relevant for topical ocular use.Minor

7. Patient Counselling

  • DO wash hands before use.
  • DO apply gentle pressure on the inner corner of the eye for 1-2 minutes after instillation.
  • DO wait at least 5 minutes before using other eye drops.
  • DO complete the full course as prescribed, even if symptoms improve.
  • DO NOT touch the dropper tip to your eye, fingers, or any surface.
  • DO NOT wear soft contact lenses while using this medication.
  • DO NOT drive or operate machinery until blurred vision clears.
  • DO NOT share your eye drops with others.

8. Toxicology & Storage

Overdose: Topical overdose is unlikely to cause systemic toxicity. Accidental oral ingestion may cause symptoms of NSAID overdose (nausea, vomiting, epigastric pain, GI bleeding, renal failure, metabolic acidosis) and fluoroquinolone overdose (dizziness, seizures, GI upset). Ocular overdose (excessive drops) may cause severe irritation, corneal toxicity, and blurred vision.

Storage: Store at room temperature (15°C to 25°C). Protect from light. Keep the bottle tightly closed when not in use. Do not freeze. Keep out of reach of children. Discard the bottle 4 weeks after opening to prevent contamination. Do not use if the solution is discolored or contains particles.