The Core Culprits: Ciclosporin and Cetalkonium Chloride
The stinging sensation from IKERVIS can be primarily attributed to two components: the active ingredient, ciclosporin, and the preservative, cetalkonium chloride. IKERVIS is a prescription medication used to treat severe keratitis, a condition involving inflammation of the cornea associated with dry eye disease. The therapeutic benefits of this powerful drug often come with a trade-off in initial comfort for some users.
The Impact of Ciclosporin
Ciclosporin is an immunosuppressant that works by inhibiting T-cell activation and proliferation, which helps reduce the inflammation on the eye's surface. When a patient has severe dry eye disease, their ocular surface is already in a vulnerable and inflamed state. Applying a potent anti-inflammatory agent like ciclosporin to this sensitive tissue can trigger a transient stinging or burning sensation. This is often the eye's initial reaction to a strong medicinal compound, especially when the tear film is compromised and cannot provide adequate protection.
The Role of Cetalkonium Chloride
IKERVIS is an emulsion, and it contains the preservative cetalkonium chloride. Preservatives are necessary in multi-dose eye drops to prevent microbial contamination. However, some preservatives, including cetalkonium chloride, are known to cause irritation to the eye's delicate surface, particularly with prolonged use or in sensitive individuals. While IKERVIS comes in single-dose containers, cetalkonium chloride is part of the formulation and contributes to the overall irritating potential. This is especially relevant for patients with pre-existing ocular surface disease, where the eye's tolerance for chemical agents is already low.
The Inflamed Ocular Surface: A Sensitive Substrate
For patients with severe dry eye disease and keratitis, the ocular surface is not a neutral environment; it's inflamed, compromised, and highly sensitive. Even seemingly benign artificial tears can cause irritation when instilled into an extremely dry or damaged eye. This pre-existing state of sensitivity and inflammation amplifies the irritation caused by the active and inactive ingredients in IKERVIS. As treatment progresses and the ocular surface begins to heal and inflammation subsides, the stinging sensation often lessens over time.
Comparison of Irritating Factors in IKERVIS
| Factor | Contribution to Stinging | Severity | Duration | Underlying Reason |
|---|---|---|---|---|
| Ciclosporin (Active Ingredient) | High | Mild-to-moderate, depends on severity of keratitis | Often reduces with continued treatment as inflammation improves | Immunosuppressant activity on a compromised, inflamed ocular surface |
| Cetalkonium Chloride (Preservative) | Moderate | Can cause mild irritation, especially in sensitive eyes | Persistent for as long as the medication is used, but often mild | Chemical irritant to the delicate ocular surface |
| Damaged Ocular Surface (Patient Condition) | High | Varies greatly, as dry eyes are more sensitive to any liquid | Decreases as the underlying condition improves with treatment | Compromised tear film and heightened nerve sensitivity |
Strategies to Minimize the Sting
While the stinging from IKERVIS is a common and often unavoidable side effect, there are several strategies patients can employ to make the experience more manageable and improve compliance.
- Use Other Drops First: Some eye care professionals suggest using a non-preserved, lubricating eye drop 15-30 minutes before applying IKERVIS. This can help create a protective barrier on the ocular surface and hydrate the eye before the ciclosporin is instilled. It is crucial to follow your doctor's instructions on which drops can be used concurrently and to wait the appropriate amount of time between applications.
- Chill the Medication: Storing the unopened single-dose containers of IKERVIS in the refrigerator can provide temporary relief by chilling the drops. The cooler temperature can offer a soothing sensation that helps counteract the initial burning. Remember to store them at the manufacturer's recommended temperature long-term, which is typically at room temperature.
- Follow Proper Instillation Technique: Ensure you are applying the drops correctly to minimize discomfort. After instilling the drop, close your eye and press a finger to the inner corner of your eye for about two minutes. This helps prevent the medication from draining into the rest of the body and maximizes local activity.
- Talk to Your Doctor: If the stinging is severe or does not improve over time, speak with your ophthalmologist. They may recommend additional or alternative treatments, such as a short course of topical steroids, to reduce the initial inflammation and make the transition to IKERVIS more comfortable.
Conclusion
The temporary stinging sensation experienced when using IKERVIS is a well-documented and common side effect, primarily resulting from the therapeutic action of ciclosporin on an already inflamed ocular surface and the presence of the preservative cetalkonium chloride. For most patients, this discomfort is temporary and decreases as the underlying inflammation of dry eye disease improves with consistent treatment. By understanding the causes and employing simple strategies like pre-hydrating the eye or chilling the drops, patients can effectively manage the initial irritation and continue with their prescribed treatment. Always consult with a healthcare professional to address concerns and ensure the best possible therapeutic outcome. For more information, refer to the European Medicines Agency's detailed product information.
