Of course. Here is a comprehensive, evidence-based drug monograph for Xiidra, formatted as a complete blog post.
*Introduction
Xiidra (lifitegrast ophthalmic solution) 5% is a prescription medication approved by the U.S. Food and Drug Administration (FDA) for the treatment of the signs and symptoms of dry eye disease (DED). It belongs to a novel class of drugs known as lymphocyte function-associated antigen-1 (LFA-1) antagonists. Unlike traditional artificial tears that provide symptomatic relief, Xiidra is a pharmacologic therapy that targets the underlying inflammation associated with dry eye disease.
Mechanism of Action
Dry eye disease is often driven by a cycle of inflammation on the ocular surface. Xiidra's mechanism of action is specifically designed to interrupt this inflammatory process.
Lifitegrast, the active ingredient, is a small molecule integrin antagonist. It works by selectively inhibiting the binding of lymphocyte function-associated antigen-1 (LFA-1) to its cognate ligand, intercellular adhesion molecule-1 (ICAM-1). LFA-1/ICAM-1 interaction is a critical step in the formation of the immunological synapse between antigen-presenting cells (APCs) and T-cells. By blocking this interaction, Xiidra prevents T-cell activation, recruitment, and subsequent release of pro-inflammatory cytokines. This action helps to reduce the inflammation on the ocular surface, thereby alleviating both the signs (e.g., corneal staining) and symptoms (e.g., eye dryness, discomfort) of dry eye disease.
Indications
Xiidra is indicated for the treatment of the signs and symptoms of dry eye disease in adult patients.
Dosage and Administration
* Dosage Form: Sterile ophthalmic solution, 5% (50 mg/mL). * Recommended Dosage: Instill one drop in each eye twice daily (approximately every 12 hours). * Administration: 1. Wash hands thoroughly. 2. Remove the single-use vial from the foil pouch. 3. Twist off the vial's cap. 4. Tilt head back and pull down the lower eyelid to create a pouch. 5. Instill one drop into the conjunctival sac of the affected eye(s). Do not allow the tip of the vial to touch the eye or any surface. 6. Discard the vial after use, even if there is solution remaining. * Special Populations: * Renal or Hepatic Impairment: No dosage adjustment is recommended, as systemic exposure to lifitegrast is minimal. * Pediatric Use: Safety and effectiveness have not been established. * Geriatric Use: No overall differences in safety or effectiveness have been observed.
Pharmacokinetics
* Absorption: Lifitegrast is minimally absorbed systemically following topical ocular administration. The mean plasma concentration (Cmax) was below the level of quantification (1 ng/mL) in most subjects. * Distribution: Plasma protein binding is >99%. Systemic distribution is negligible. * Metabolism: Lifitegrast is metabolized primarily via hydrolysis and oxidation. It is a substrate of P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP). * Elimination: The half-life in plasma is approximately 2.7 hours. The primary route of elimination is via feces following oral administration; however, due to minimal systemic absorption after ocular use, traditional elimination pathways are not clinically significant.
Contraindications
Xiidra is contraindicated in patients with known hypersensitivity to lifitegrast or any of the excipients in the formulation.
Warnings and Precautions
* Eye Irritation: Instillation of Xiidra may cause temporary irritation (e.g., burning or instillation site discomfort). Patients should not wear contact lenses if their eye is red. Xiidra should not be instilled while wearing contact lenses. Lenses may be reinserted 15 minutes after instillation. * Hypersensitivity Reactions: There have been reports of hypersensitivity reactions, including eyelid edema, conjunctival hyperemia, and dyspnea. Discontinue use if such reactions occur. * Taste Disturbance (Dysgeusia): A common adverse reaction is altered taste sensation following instillation. This is usually transient.
Drug Interactions
Formal drug interaction studies have not been conducted with Xiidra. However, due to its minimal systemic absorption, clinically significant drug interactions are unlikely. Theoretically, for the minimal amount systemically absorbed, it could interact with drugs that are inhibitors of P-gp or BCRP (e.g., cyclosporine, quinidine, verapamil), but this risk is considered negligible.
Adverse Effects
The most common adverse reactions reported in 5-25% of patients were: * Instillation site irritation (burning sensation) * Blurred vision * Altered taste sensation (dysgeusia) * Reduced visual acuity * Dry eye * Eye discomfort
Most of these effects were mild to moderate in severity.
Monitoring Parameters
* Efficacy: Patient-reported symptoms of dry eye (e.g., dryness, grittiness, visual fatigue) and objective signs assessed by an eye care professional (e.g., corneal staining via fluorescein, conjunctival redness, tear break-up time). * Safety: Monitor for signs of hypersensitivity (eyelid swelling, redness, respiratory difficulty) and patient tolerance to the therapy (complaints of persistent irritation or taste disturbances).
Patient Education
* Use Xiidra exactly as prescribed: one drop in each eye, twice daily. * This vial is for single-use only. Throw it away after use, even if there is medicine left. * Do not let the tip of the vial touch your eye, fingers, or any other surface to avoid contamination. * You may experience a temporary blurring of vision or a unusual taste in your mouth immediately after using the drops. These effects are usually short-lived. * Do not wear contact lenses if your eyes are red. Wait at least 15 minutes after instilling Xiidra before reinserting contact lenses. * If you experience severe eye pain, worsening redness, or symptoms of an allergic reaction (eyelid swelling, trouble breathing), stop using Xiidra and contact your healthcare provider immediately. * Store the unopened foil pouches in a refrigerator (36°F to 46°F / 2°C to 8°C). Once a vial is opened, it must be used immediately and cannot be stored.
References
1. Xiidra® (lifitegrast ophthalmic solution) [Prescribing Information]. Lexington, MA: Shire US Inc.; July 2023. 2. Donnenfeld, E., Karpecki, P., Majmudar, P., et al. (2016). Safety of Lifitegrast Ophthalmic Solution 5.0% in Patients With Dry Eye Disease: A 1-Year, Multicenter, Randomized, Placebo-Controlled Study. Cornea, 35(6), 741–748. 3. Holland, E., Luchs, J., Karpecki, P. M., et al. (2017). Lifitegrast for the Treatment of Dry Eye Disease: Results of a Phase III, Randomized, Double-Masked, Placebo-Controlled Trial (OPUS-3). Ophthalmology, 124(1), 53–60. 4. Semba, C. P., Torkildsen, G. L., Lonsdale, J. D., et al. (2016). A Phase 2 Randomized, Double-Masked, Placebo-Controlled Study of the Safety and Efficacy of Lifitegrast in the Treatment of Dry Eye Disease. Ophthalmology, 123(1), 105–113. 5. Perez, V. L., Pflugfelder, S. C., Zhang, S., et al. (2016). Lifitegrast, a Novel Integrin Antagonist for Treatment of Dry Eye Disease. Ocular Surface, 14(2), 207–215.