1. Clinical Overview
Prednisolone (1% w/v) is a topical ophthalmic suspension containing a potent synthetic corticosteroid. It is primarily used to treat inflammatory conditions of the eye, including the conjunctiva, cornea, and anterior segment. It exerts anti-inflammatory, anti-allergic, and immunosuppressive effects by inhibiting multiple inflammatory mediators. In the Indian context, it is a cornerstone treatment for non-infectious ocular inflammation and post-operative management.
| Onset | Duration | Bioavailability |
|---|---|---|
| Therapeutic anti-inflammatory effects typically begin within hours of administration, with noticeable symptomatic relief often within 1-2 days. | Duration is dose-dependent but generally lasts 12-24 hours per instillation due to local tissue binding and sustained release from the suspension. | Topical ophthalmic bioavailability is low, estimated at <5% systemically. The primary action is local at the ocular tissues. |
2. Mechanism of Action
Prednisolone is a glucocorticoid receptor agonist. It diffuses across cell membranes and binds with high affinity to cytoplasmic glucocorticoid receptors. The receptor-ligand complex translocates to the nucleus, where it modulates gene transcription. It induces the synthesis of anti-inflammatory proteins (like lipocortin-1) and represses the synthesis of pro-inflammatory mediators.
3. Indications & Uses
- Allergic conjunctivitis
- Anterior uveitis (iritis, iridocyclitis)
- Keratitis (non-ulcerative, superficial punctate)
- Post-operative inflammation following ocular surgery
- Episcleritis
- Scleritis (non-necrotizing)
4. Dosage & Administration
Adult Dosage: Initially, 1 to 2 drops instilled into the conjunctival sac of the affected eye(s) every 1 to 4 hours during the day. Frequency is tapered as inflammation subsides, typically to 1 drop 2 to 4 times daily. For severe inflammation, more frequent dosing (e.g., every 15-30 minutes initially) may be required under close supervision.
Administration: 1. Wash hands thoroughly. 2. Shake the suspension well before each use. 3. Tilt head back, pull down the lower eyelid to form a pouch. 4. Instill the prescribed number of drops into the pouch without touching the dropper tip to the eye, eyelid, or any surface. 5. Close eyes gently for 1-2 minutes. Apply gentle pressure to the nasolacrimal duct (inner corner of the eye) for 1 minute to minimize systemic absorption. 6. If using other eye drops, wait at least 5-10 minutes between applications. Ointments should be applied last.
5. Side Effects
Common side effects may include:
- Transient burning or stinging upon instillation
- Blurred vision temporarily after application
- Mild irritation or itching
- Watery eyes (epiphora)
- Dryness or sensation of foreign body
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Warfarin/Acenocoumarol | Prednisolone may alter anticoagulant response; monitor INR closely. | Moderate |
| Antidiabetic drugs (Insulin, Metformin, Sulfonylureas) | Prednisolone may antagonize hypoglycemic effect, leading to hyperglycemia. | Moderate |
| NSAIDs (Topical or Systemic like Diclofenac, Ketorolac) | Increased risk of gastrointestinal ulceration and impaired wound healing. Topically, combined use may increase risk of corneal melt. | Moderate |
| Potassium-depleting diuretics (Furosemide, Hydrochlorothiazide) | Enhanced risk of hypokalemia. | Moderate |
| CYP3A4 inducers (Phenobarbital, Phenytoin, Rifampicin) | May increase metabolism of prednisolone, reducing its efficacy. | Moderate |
| CYP3A4 inhibitors (Ketoconazole, Itraconazole, Clarithromycin) | May decrease metabolism of prednisolone, increasing risk of systemic toxicity. | Moderate |
| Live Vaccines (MMR, Varicella, OPV) | Immunosuppression may enhance replication of vaccine virus, increasing risk of infection. | Major |
7. Patient Counselling
- DO shake the bottle well before each use.
- DO wash your hands before and after use.
- DO apply pressure on the inner corner of the eye (nasolacrimal duct) for 1 minute after instillation to reduce systemic side effects.
- DO wait at least 5-10 minutes before instilling any other eye medication.
- DO NOT touch the dropper tip to your eye, fingers, or any surface to avoid contamination.
- DO NOT wear contact lenses while using this medication or during an active ocular inflammatory condition unless approved by your doctor.
- DO NOT stop the medication abruptly if used for more than 10 days; taper as directed by your doctor to avoid rebound inflammation.
- DO NOT drive or operate machinery until your vision clears after instillation.
8. Toxicology & Storage
Overdose: Topical overdose is unlikely to cause acute systemic toxicity. Accidental oral ingestion of eye drops may cause symptoms of systemic corticosteroid excess: hypertension, hyperglycemia, fluid retention, hypokalemia, psychosis, Cushingoid features. Ocular overdose can lead to severe elevation of IOP, corneal damage, and exacerbation of infection.
Storage: Store at controlled room temperature (15°C to 25°C). Protect from light and freezing. Keep the bottle tightly closed when not in use. Do not store in the bathroom. Keep out of reach and sight of children. Discard the bottle 28 days after first opening to prevent contamination. Do not use if the suspension is discolored or contains particles.