Ophthalmic steroids with anti-infectives

Definition and Classification

Ophthalmic steroids with anti-infectives represent a dual-purpose pharmacological class formulated specifically for topical ocular application. These combinations merge corticosteroids (which suppress inflammation) with antibiotics or antivirals (which control or prevent infections). Their synergistic action makes them valuable in treating or preventing inflammatory ocular conditions that either originate from infection or carry a high risk of secondary microbial colonization. These formulations are used post-operatively, in trauma, or for infectious conjunctivitis, keratitis, blepharitis, or uveitis where inflammation and infection co-exist.

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1. Mechanism of Action

These combination agents operate via two pharmacological actions:

A. Corticosteroid Component (Anti-Inflammatory)

• Inhibits phospholipase A2, blocking arachidonic acid cascade.

• Reduces inflammatory cytokines (e.g., prostaglandins, leukotrienes).

• Decreases leukocyte migration, vascular permeability, capillary dilation.

• Controls swelling, redness, irritation, and tissue damage.

B. Anti-Infective Component

• May include broad-spectrum antibiotics or antivirals.

• Antibiotics interfere with bacterial DNA replication, protein synthesis, or cell wall integrity.

• Antivirals inhibit viral DNA polymerase, replication, or entry.

• Purpose is to treat or prevent bacterial or viral ocular infections.

The combination reduces the need for separate administration, improves compliance, and helps prevent secondary infection during corticosteroid immunosuppression.

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2. Formulations and Routes of Administration

• Formulations: Ophthalmic drops, ointments, and gels.

• Routes: Topical to the eye (ocular surface and conjunctival sac), or sometimes periocular use.

• Sterile, preservative-free options may be used in sensitive eyes or post-surgery.

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3. Representative Products

Corticosteroid	Anti-Infective	Brand Examples
Dexamethasone	Tobramycin	TobraDex, Tobradex ST
Dexamethasone	Neomycin + Polymyxin B	Maxitrol
Dexamethasone	Ciprofloxacin	Ciprodex (also otic use)
Dexamethasone	Gatifloxacin	Zylet
Prednisolone acetate	Ciprofloxacin	Pred-G
Hydrocortisone	Neomycin + Polymyxin B	Cortisporin Ophthalmic
Loteprednol etabonate	Tobramycin	Zylet
Fluorometholone	Neomycin + Polymyxin B	FML-Neo
Dexamethasone	Ofloxacin	Oflodex
Prednisolone acetate	Sulfacetamide sodium	Blephamide

4. Indications

These agents are indicated in ocular conditions that involve both inflammation and risk of infection, such as:

• Post-operative inflammation (e.g., cataract, glaucoma surgeries)

• Bacterial conjunctivitis

• Blepharitis with swelling

• Superficial keratitis

• Scleritis or episcleritis

• Anterior uveitis (with bacterial involvement)

• Traumatic ocular injury

• Contact lens-related infections with inflammation

They are not generally used for viral infections (except herpes zoster ophthalmicus under strict control) and are contraindicated in herpes simplex keratitis.

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5. Common Corticosteroid Agents and Their Profiles

Agent	Potency	Key Features
Dexamethasone	High	Rapid onset, effective in anterior inflammation
Prednisolone	High	Preferred for post-op and severe ocular inflammation
Fluorometholone	Moderate	Lower IOP elevation risk, often for surface inflammation
Loteprednol	Soft steroid	Less likely to raise IOP; suitable for long-term use
Hydrocortisone	Low	Mild inflammation or chronic therapy

6. Common Anti-Infective Agents and Their Coverage

Agent	Class	Coverage
Tobramycin	Aminoglycoside	Gram-negatives, including Pseudomonas
Neomycin	Aminoglycoside	Gram-positive and Gram-negative (limited)
Polymyxin B	Polypeptide	Gram-negative rods
Ciprofloxacin	Fluoroquinolone	Broad-spectrum including Pseudomonas
Ofloxacin	Fluoroquinolone	Broad-spectrum, good ocular penetration
Gatifloxacin	4th-gen Fluoroquinolone	Enhanced Gram-positive and Gram-negative
Sulfacetamide sodium	Sulfonamide	Gram-positive cocci and some Gram-negatives

7. Pharmacokinetics

• Onset: Topical agents typically act within 1–2 hours.

• Duration: Variable by formulation (drops vs ointments); ointments last longer but blur vision.

• Absorption: Minimal systemic absorption with proper application; still possible via nasolacrimal duct.

• Elimination: Primarily local metabolism and tear drainage.

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8. Adverse Effects

Corticosteroid-related	Anti-infective-related
↑ Intraocular pressure (IOP)	Local hypersensitivity
Cataract formation (posterior subcapsular)	Superinfection with fungi or resistant bacteria
Delayed wound healing	Corneal toxicity (especially aminoglycosides)
Secondary herpetic activation	Local irritation, burning, or stinging

9. Contraindications

• Viral keratitis (HSV dendritic ulcers)

• Fungal eye infections

• Tuberculosis of the eye

• Hypersensitivity to any ingredient

• Untreated acute purulent infection without concurrent anti-infective coverage

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10. Precautions and Monitoring

• Monitor IOP during prolonged use (especially >10 days)

• Perform slit-lamp exams to assess for cataracts or corneal thinning

• Avoid long-term use unless supervised by an ophthalmologist

• Consider culturing in unresponsive infections

• Avoid contact lens use during therapy unless advised

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11. Drug Interactions

Although topical, systemic effects and interactions may occur:

Drug	Interaction
Other IOP-elevating drugs	Additive risk of glaucoma
Systemic corticosteroids	Potentiation of immunosuppression
NSAIDs	Increased risk of corneal thinning
Anticoagulants	Minimal, but caution with ulceration risk

12. Dosing and Administration

• Typical Dosing: 1–2 drops in affected eye(s) every 4–6 hours

• Ointments: Apply 1 cm ribbon into the conjunctival sac 2–4 times daily

• Tapering: Required to prevent rebound inflammation

• Administration Advice:

  • Wash hands before use

  • Avoid touching dropper tip

  • Close eye and press tear duct for 1–2 minutes after administration to reduce systemic absorption

  • Wait at least 5 minutes before applying another eye product

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13. Special Populations

Population	Considerations
Pediatric	Safe under supervision; avoid chronic use due to IOP rise
Elderly	Increased susceptibility to IOP elevation, cataracts
Pregnancy	Generally avoid unless essential; some agents are category C
Lactation	Use with caution; systemic absorption is minimal but possible

14. Clinical Pearls

• Always rule out herpetic infections before prescribing

• Use combination agents only when both inflammation and infection are present

• In cases of steroid responders (rapid IOP rise), use loteprednol-based products

• Some patients may develop contact allergy to neomycin—watch for worsening inflammation

• Prolonged or inappropriate use may lead to fungal superinfection

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15. Summary Table of Common Products

Brand Name	Steroid	Antibiotic	Indications
TobraDex	Dexamethasone	Tobramycin	Post-op inflammation + infection
Maxitrol	Dexamethasone	Neomycin + Polymyxin B	Bacterial conjunctivitis with inflammation
Zylet	Loteprednol	Tobramycin	Inflammatory ocular conditions with risk of infection
Pred-G	Prednisolone	Gentamicin or Ciprofloxacin	Corneal ulcers, blepharitis
FML-Neo	Fluorometholone	Neomycin	Mild inflammation with infection