Xiidra
Xiidra
Generic Name
Xiidra
Mechanism
* Cyclosporine A (0.05 %)—a lipid-soluble cyclosporine derivative formulated as a 5 % vehicle–termed or in a micro‑emulsion.
* Inhibits T‑cell activation by forming a complex with cyclophilin, thereby blocking calcineurin and preventing transcription of pro‑inflammatory cytokines (IL‑2, IFN‑γ, TNF‑α).
* Decreases ocular surface inflammation, restores tear film stability, and promotes conjunctival goblet‑cell density.
* Secondary neuroprotective effect: May enhance tear secretion via modulation of lacrimal gland innervation.
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Pharmacokinetics
| Parameter | Value |
| Absorption | *Topically applied* – limited systemic absorption; peak tear concentration at ~1–3 h post‑dose. |
| Distribution | Predominantly retained on the ocular surface; minimal penetration across corneal epithelium. |
| Metabolism | Metabolized by ocular CYP3A4 and esterases to inactive metabolites. |
| Elimination | Mainly through tear drainage and systemic clearance; negligible systemic bioavailability (<1 %). |
| Half‑life | Approx. 2–3 h in tears; ocular tissue half‑life ~10–12 h. |
| Special Populations | No dose adjustment needed for age, renal, or hepatic impairment (systemic exposure negligible). |
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Indications
* Keratoconjunctivitis sicca (dry eye disease) as an adjunct to artificial tears.
* Use is approved for both sexes, ≥ 18 years old.
* Recommended for patients with an inadequate response to lubricants alone.
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Contraindications
| Category | Note | |
| Contraindications | Known hypersensitivity to cyclosporine, cyclosporine, or any component of the formulation. | |
| Warnings | *No ocular surface infections* at the time of initiation. | |
| Precautions | Monitor for ocular irritation or stinging; ensure proper application technique. If conjunctival inflammation worsens or persists for > 30 days, reevaluate therapy. |
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Dosing
* Adult: 1 drop (≈ 50 µL) in each eye twice daily (morning & evening).
* Administration tip: Instill prior to eye opening; allow 5–10 min for absorption before shaving or using contact lenses.
* Special Instructions: Avoid using in conjunction with other CsA formulations to prevent cumulative irritation.
* Follow‑up: Reevaluate at 4 weeks; adjust based on symptom resolution and ocular surface status.
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Adverse Effects
| Adverse Effect | Frequency | Remarks |
| Ocular stinging or burning | ~30–40 % | Often transient within 10–15 min; reduce severity with warm compresses. |
| Blurred vision | ~10 % | Typically after instillation; may resolve after 30 min. |
| Allergic conjunctivitis | ~3 % | Presents as itching, redness; discontinue if severe. |
| Dry eye worsening (paradoxical) | < 5 % | Rare; advise immediate ophthalmology consultation. |
| Systemic immunosuppression | < 1 % | No clinically relevant systemic toxicity at ocular dosing. |
| Others (e.g., eye pain, redness) | < 5 % | Non‑serious, usually self‑limited. |
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Monitoring
| Parameter | Frequency | Rationale |
| Ocular surface assessment (e.g., Schirmer’s test, TBUT, slit‑lamp exam) | Every 4–6 weeks | Track improvement and detect emerging irritation. |
| Patient symptoms (dryness, foreign body sensation) | Every visit | Gauge therapeutic benefit. |
| Systemic signs (fever, rash) | At first visit & whenever patient reports systemic symptoms | Detect rare systemic reactions. |
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Clinical Pearls
1. Application Technique Matters – Applying Xiidra immediately before eye opening and allowing 5–10 min promotes deeper penetration and reduces stinging.
2. Lyophilized vs. Emulsion – Unlike Lotrafilcon C or ReNu, Xiidra is a pure CsA emulsion; patients with contact‑lens intolerance may prefer nightly dosing only if it reduces irritation.
3. Switching from Thus or Restasis – A 1‑week wash‑out period is recommended to avoid overlapping CsA exposure and potential cumulative ocular irritation.
4. Use in TIU Patients – In patients with tear‑film instability but robust lacrimal function, pair Xiidra with preservative‑free artificial tears for maximal benefit.
5. Adjunctive Anti‑inflammatory Measures – Tetracycline or prednisolone eye drops can be used short‑term for superimposed infectious or inflammatory flare‑ups, but never concurrently with continuous CsA therapy.
6. Patient Education – Emphasize that clinical improvement may take 4–8 weeks; highlight that rapid on‑set stinging is typically benign and self‑limited.
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• > Key Takeaway: Xiidra provides a targeted immunomodulatory strategy for dry eye that leverages cyclosporine A’s anti‑inflammatory properties, offering steady relief over weeks with minimal systemic absorption. Proper instillation technique and patient patience are essential to maximize therapeutic outcomes.