Azelastine eye drops in the treatment of seasonal allergic conjunctivitis or rhinoconjunctivitis in young children

Topical antihistamines and mast cell stabilisers for treating seasonal and perennial allergic conjunctivitis

BACKGROUND

Seasonal/perennial allergic conjunctivitis is the most common allergic conjunctivitis, usually with acute manifestations when a person is exposed to allergens and with typical signs and symptoms including itching, redness, and tearing. The clinical signs and symptoms of allergic conjunctivitis are mediated by the release of histamine by mast cells. Histamine antagonists (also called antihistamines) inhibit the action of histamine by blocking histamine H1 receptors, antagonising the vasoconstrictor, and to a lesser extent, the vasodilator effects of histamine. Mast cell stabilisers inhibit degranulation and consequently the release of histamine by interrupting the normal chain of intracellular signals. Topical treatments include eye drops with antihistamines, mast cell stabilisers, non-steroidal anti-inflammatory drugs, combinations of the previous treatments, and corticosteroids. Standard treatment is based on topical antihistamines alone or topical mast cell stabilisers alone or a combination of treatments. There is clinical uncertainty about the relative efficacy and safety of topical treatment.

OBJECTIVES

The objective of this review was to assess the effects of topical antihistamines and mast cell stabilisers, alone or in combination, for use in treating seasonal and perennial allergic conjunctivitis.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2014, Issue 7), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to July 2014), EMBASE (January 1980 to July 2014), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 17 July 2014. We also searched the reference lists of review articles and relevant trial reports for details of further relevant publications.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing topical antihistamine and mast cell stabilisers, alone or in combination, with placebo, no treatment or to any other antihistamine or mast cell stabiliser, or both, that examined people with seasonal or perennial allergic conjunctivitis, or both. The primary outcome was any participant-reported evaluation (by questionnaire) of severity of four main ocular symptoms: itching, irritation, watering eye (tearing), and photophobia (dislike of light), both separately and, if possible, by an overall symptom score. We considered any follow-up time between one week and one year.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed risk of bias. Disagreements were resolved by discussion among review authors and the involvement of a third review author. We followed standard methodological approaches used by Cochrane.

MAIN RESULTS

We identified 30 trials with a total of 4344 participants randomised, with 17 different drugs or treatment comparisons. The following antihistamines and mast cell stabilisers were evaluated in at least one RCT: nedocromil sodium or sodium cromoglycate, olopatadine, ketotifen, azelastine, emedastine, levocabastine (or levocabastine), mequitazine, bepotastine besilate, combination of antazoline and tetryzoline, combination of levocabastine and pemirolast potassium. The most common comparison was azelastine versus placebo (nine studies).We observed a large variability in reporting outcomes. The quality of the studies and reporting was variable, but overall the risk of bias was low. Trials evaluated only short-term effects, with a range of treatment of one to eight weeks. Meta-analysis was only possible in one comparison (olopatadine versus ketotifen). There was some evidence to support that topical antihistamines and mast cell stabilisers reduce symptoms and signs of seasonal allergic conjunctivitis when compared with placebo. There were no reported serious adverse events related to the use of topical antihistamine and mast cell stabilisers treatment.

AUTHORS' CONCLUSIONS

It seems that all reported topical antihistamines and mast cell stabilisers reduce symptoms and signs of seasonal allergic conjunctivitis when compared with placebo in the short term. However, there is no long-term data on their efficacy. Direct comparisons of different antihistamines and mast cell stabilisers need to be interpreted with caution. Overall, topical antihistamines and mast cell stabilisers appear to be safe and well tolerated. We observed a large variability in outcomes reported. Poor quality of reporting challenged the synthesis of evidence.

Azelastine hydrochloride, a dual-acting anti-inflammatory ophthalmic solution, for treatment of allergic conjunctivitis

Over 50% of patients who seek treatment for allergies present with ocular symptoms. Our current ability to control ocular allergic symptoms is greater than ever before. Newer dual-acting topical eyedrops attack multiple facets of the allergic cascade. Azelastine has antihistaminic effects providing immediate relief, mast cell stabilization providing early-phase intervention, and inhibition of expression and activation of anti-inflammatory mediators which characterize the late phase of the immune reaction. The ophthalmic eyedrop formulation is approved for treatment of allergic conjunctivitis in adults and children aged over 3 years. In clinical trials comparing azelastine with other dual-acting eyedrops, such as levocabastine and olopatadine, azelastine was reported to be slightly less efficacious and to sting briefly upon administration. Even so, many patients experienced the full benefit of symptom relief, and preferred azelastine. As a broad-spectrum drug, azelastine offers many desirable properties for management of ocular allergies. Because it can often produce maximal effect with just twice-daily dosing, azelastine is a particularly good choice for the allergic population in whom minimizing exposure to topical products and preservatives is a key concern.

Ocular allergy in pediatric practice

Allergies occur frequently in all pediatric age groups, affecting up to 40% of children. Allergic conjunctivitis is the most common ocular allergy syndrome among children, with atopic keratoconjunctivitis and vernal keratoconjunctivitis comprising less common, but potentially more severe, forms of ocular allergy. In this article, we review the impact, diagnosis, potential complications, and treatment of these ocular allergic pediatric conditions. Early detection is necessary to prevent potentially serious consequences of pediatric ocular allergy. Involvement of pediatric ophthalmologists may be necessary to avoid preventable vision loss in severe cases.

Emerging drugs for ocular allergy

Ocular allergy is a common condition that usually affects the conjunctiva of the eye and is, therefore, often referred to as allergic conjunctivitis. The severity of the disease can range from mild itching and redness, as seen in seasonal allergic conjunctivitis, to the more severe, sight-threatening forms such as vernal and atopic keratoconjunctivitis. The central mechanism in the pathogenesis of these diseases is IgE-mediated mast cell degranulation and activation of T lymphocytes, eosinophils and conjunctival structural cells. The pharmacotherapy of allergic conjunctivitis consists of several classes of drugs: antihistamines, mast cell stabilisers, dual-acting agents and corticosteroids. None of the available drugs completely abolishes the development of ocular allergy. For this reason, new topical antiallergic/anti-inflammatory agents are currently and continually under clinical trials. This review provides a background to ocular allergic diseases, the medical need for therapy and current and potential new treatments.

Ocular Allergic Disease: Mechanisms, Disease Sub-types, Treatment

Ocular allergy refers to a variety of hypersensitivity disorders that affect the lid, conjunctiva, and/or cornea. Its incidence is estimated at over 20% of the general population in the United States. This review will discuss the various forms of ocular allergy, their pathophysiology, clinical presentation, and treatment. New frontiers in mechanisms, therapy, and management in the office are emphasized throughout.

Rapid anti-inflammatory action of azelastine eyedrops for ongoing allergic reactions

BACKGROUND

Some second-generation antihistamines have anti-inflammatory activities, but the clinical relevance of this property is still unclear.

OBJECTIVE

The aim of our study was to investigate the effects of azelastine when administered during the early-phase reaction.

METHODS

This investigation was designed as a randomized, placebo-controlled, double-blind, parallel-group study. Clinical and inflammatory events were evaluated after a single dose of azelastine eyedrops or placebo was administered 30 minutes after an allergen-specific conjunctival challenge. Twenty outpatients with allergic rhinoconjunctivitis attributable to Parietaria judaica were enrolled in the study outside the pollen season. Patients were evaluated at baseline, after allergen challenge (at 30 minutes), and after administration of azelastine (at 30 minutes and at 6 hours). The following variables were evaluated: hyperemia, lacrimation, itching, eyelid swelling, number of inflammatory cells (neutrophils, eosinophils, monocytes, and lymphocytes), and intercellular adhesion molecule-1 expression on conjunctival epithelial cells.

RESULTS

Azelastine, in comparison to placebo, significantly reduced symptom scores, number of inflammatory cells, and intercellular adhesion molecule-1 expression during the early- and late-phase reaction.

CONCLUSIONS

The ability of azelastine to reduce symptoms and inflammation during an ongoing allergic reaction can be considered concrete and convincing proof of a clinically relevant anti-inflammatory activity.

Topical azelastine in perennial allergic conjunctivitis

OBJECTIVE

Azelastine is a selective H(1)-receptor antagonist that inhibits histamine release and interferes with activation of several other mediators of allergic inflammation. Together with demonstrated efficacy in seasonal allergic conjunctivitis, azelastine indicated a therapeutic potential for perennial allergic conjunctivitis (PAC). The present study aimed to evaluate azelastine eye drops in patients with PAC compared to placebo.

RESEARCH DESIGN AND METHODS

A multinational trial in 22 centres randomised 139 patients to twice-daily treatment for 6 weeks with masked 0.05% azelastine eye drops, matching masked placebo, or open-label levocabastine. Randomisation required a sum itching and conjunctival redness score of at least 3 (0-6 scale) after 1 week of placebo. The change in sum score was evaluated during treatment.

RESULTS

Azelastine significantly improved itching and conjunctival redness compared to placebo (p < 0.001) with global tolerability that was not substantially different from placebo. On day 7, the mean symptoms sum score improved with azelastine by 1.9 +/- 1.1 and with levocabastine by 1.5 +/- 1.2 compared to placebo (0.6 +/- 1.1) from baseline values of 3.7-3.8. The sum scores continued to improve up to day 42. Daily patient logs confirmed the clinically assessed scores. Most frequent adverse events following azelastine were bitter taste and application site reaction.

CONCLUSIONS

Topical azelastine progressively improved itching and conjunctival redness in PAC patients compared to placebo and was at least as effective as levocabastine. Rapid relief is consistent with H(1)-receptor antagonist action, while continued improvement up to 6 weeks may be consistent with mechanisms involving other mediators of allergic inflammation.

Comparison of the efficacy and tolerability of topically administered azelastine, sodium cromoglycate and placebo in the treatment of seasonal allergic conjunctivitis and rhino-conjunctivitis

OBJECTIVE AND SETTING

Azelastine (AZE) in a novel, eye drop, formulation, was compared with topically applied sodium cromoglycate (SCG) and placebo (PLA) in the treatment of seasonal allergic conjunctivitis or rhino-conjunctivitis in a multicentre, parallel group study.

RESEARCH DESIGN

144 subjects ranging in age from 16 to 65 years participated. All had at least a 2-year history of seasonal allergic conjunctivitis and were symptomatic at the time of inclusion. Medications were administered topically either twice daily (AZE/PLA) or four times daily (SCG) over a 2-week treatment period. Method and outcome measures: Azelastine and placebo were compared double-blind; the comparison versus SCG was carried out in an open manner. Itching, redness, flow of tears, eyelid swelling, foreign-body sensation, photophobia, soreness and discharge were scored on a 4-point severity scale.

RESULTS

Results for the decrease of main conjunctivitis symptoms (itching, tearing and conjunctival redness) showed a marked effect for both active treatments on day 3 with a sustained improvement on days 7 and 14. A clear response to treatment (an improvement of sum scores for day 3 of >/=3 points compared to baseline) occurred in 85.4% of azelastine-treated patients, 83.0% of sodium cromoglycate patients and 56.3% of placebo patients. Response rates for both active treatments were statistically superior to those for placebo (azelastine p = 0.005; sodium cromoglycate p = 0.007). Global assessment of efficacy was at least 'satisfactory' for 90.0% of azelastine patients, 81.3% of sodium cromoglycate patients and 66.3% of placebo-treated patients. The most frequent adverse effects were transient application site reactions which tended to disappear with increasing duration of treatment, and, less frequently, taste perversion.

CONCLUSION

The results of this study indicate that the therapeutic use of azelastine eye drops in patients with seasonal allergic conjunctivitis or rhino-conjunctivitis can be recommended.

Topical immunopharmacology of ocular allergies

PURPOSE OF REVIEW

To review the histamine-1 receptor antagonists, mast cell blockers and natural agents with such actions that can be used for the topical treatment of ocular allergies.

RECENT FINDINGS

Increasing evidence indicates that some histamine-1 receptor antagonists have additional actions to inhibit secretion of inflammatory mediators, especially cytokines, from ocular mast cells and other cell types. Emerging information suggests that such actions may be through regulation of intracellular calcium ion levels of NF-kappaB activation.

SUMMARY

A number of available drugs and natural non-prescription agents may have anti-histaminic and anti-inflammatory actions.

Conjunctival provocation testing: overview of recent clinical trials in ocular allergy

PURPOSE OF REVIEW

The conjunctival provocation test is a human model of ocular allergy that has been used to study the ocular response to allergenic stimuli and to evaluate antiallergic therapy. The review will discuss recent studies using the conjunctival provocation test and other models of ocular allergy, and evaluate the relative merits of different models.

RECENT FINDINGS

The conjunctival provocation test has allowed investigators to recruit large numbers of allergic individuals who, although asymptomatic, can be challenged with the conjunctival administration of allergen. Observations of the eye can be made before and after challenge, and cells and mediators may be sampled from the ocular surface. In addition, the effectiveness of antiallergic therapy can be evaluated, usually by pretreating the two eyes with different forms or doses of drug.

SUMMARY

Considerable useful information has been gained about the ocular allergic response and drug efficacy using the conjunctival provocation test and naturally occurring seasonal allergic conjunctivitis.

Update on ocular allergy treatment

Allergy affects > 15% of the world population with a higher prevalence of 30% in westernised industrialised countries, such as the US. Allergy commonly affects various target organs including the eyes, nose, sinuses, ears, lungs and skin. However, the ocular component may be the most common and initially the most prominent disabling feature. Some patients are affected for only a few weeks to months while others have symptoms that last throughout the year. The associated healthcare costs related to allergic conjunctivitis has been commonly nestled with allergic rhinitis and has been reported to be as high as US$5.9 billion in the US, with 25% (US$1.5 billion) of it related to medication use. The expenditures related to ocular prescription medication has only recently risen in the past decade from US$6 million in early 1990s to > US$200 million in the new millennium with a projected continuous expansion of 25% per year. This appears to be due to improved prescription medications and their clear benefit over the less efficacious over-the-counter products. The actual cost of the medications and their relative price increases over the past year have ranged from 0 - 49% with an average cost of < US$ day. The newer topical medications (multiple acting agents) are focusing on multiple actions that include an antihistaminic effect to provide an immediate relief and additional delayed effects to act on the mediators of the late phase reaction without steroid side effects (glaucoma, cataracts). The paradigm for the treatment of ocular allergy ranges from primary measures (avoidance measures, cold compresses and lubrication), to secondary measures (various combination of topical agents) and tertiary measures that would include topical steroids and immunotherapy. The increased interest in advancing ocular treatment will lead to the development of additional therapies, novel pharmacokinetic delivery systems and, thus, improved healthcare outcomes for patients with allergic conjunctivitis.

Overview of ocular allergy treatment

A plethora of drugs is available for the treatment of ocular allergy. Traditional treatment includes antihistamine and antihistamine/vasoconstrictor combination eyedrops. These drugs are useful, safe, and readily available. Mast cell stabilizers are safe, effective, and an important component of antiallergic therapy. Nonsteroidal anti-inflammatory drugs also have antiallergic effects. In recent years, drugs with multiple mechanisms of action have proven to be effective antiallergics. These drugs often have mast cell stabilizing, antihistaminic, and anti-inflammatory properties. Corticosteroids are considered to be more potent than other antiallergic drugs, and modifications in their molecular structures have made certain corticosteroids suitable for the treatment of ocular allergy.

Cost effectiveness of emedastine versus levocabastine in the treatment of allergic conjunctivitis in 7 European countries

OBJECTIVE

To assess the cost effectiveness of emedastine, a new antihistamine, versus levocabastine in the treatment of acute allergic conjunctivitis (AAC) in Belgium, France, Germany, The Netherlands, Norway, Portugal and Sweden.

DESIGN AND SETTING

Randomised double-blind multicountry clinical trial followed by economic modelling from the treatment provider perspective.

PATIENTS

A total of 221 patients (109 emedastine, 112 levocabastine) with AAC were included.

METHODS

The clinical trial compared the efficacy and safety of emedastine 0.05% and levocabastine 0.05%, both twice daily, for 42 days, using ocular redness, itching, days without symptoms and clinical failure as outcome measures. The cost of first-line treatment failure, including visits, drugs and laboratory examinations, was established in each country from a panel of ophthalmologists and general practitioners. Full sensitivity analyses were conducted.

RESULTS

From day 7 to 42, patients treated with emedastine had less itching (p < 0.001) and less redness (p < 0.001). The failure rate was 10% less (p < 0.02) with emedastine and patients treated with emedastine had an incremental 8.5 days (p < 0.01) without symptoms. Emedastine and levocabastine were equally well tolerated. In all European countries, the cost of failure was lower with emedastine. Emedastine was found to be economically dominant relative to levocabastine, i.e. more effective and less expensive, in Belgium, Germany, Portugal and Sweden; in France, The Netherlands and Norway the incremental cost was low (less than 1 euro per additional symptom-free day).

CONCLUSION

Through a model based on a randomised clinical trial and cost estimates of treatment failure derived from practitioner interviews, emedastine is a cost-effective treatment of AAC.

Evaluation of the onset and duration of effect of azelastine eye drops (0.05%) versus placebo in patients with allergic conjunctivitis using an allergen challenge model

OBJECTIVE

The trial evaluated the effectiveness of the investigational antihistaminic and antiallergic compound Azelastine Eye Drops (AZE) in the treatment of allergic conjunctivitis using an allergen challenge model.

DESIGN

Randomized, double-blind, placebo-controlled, paired-eye study.

PARTICIPANTS

Adults with a history of allergic conjunctivitis (>/=2 years) who were asymptomatic throughout the trial, had a positive skin test (cat dander, grass, or ragweed pollen within the last year), and had a positive conjunctival reaction (score 2+ or more for itching and redness in both eyes on a 0-4 scale) during two separate conjunctival provocation tests (CPT) before randomization.

METHODS

Eighty patients underwent a 2-week screening period (visits 1 and 2) that included a CPT during visit 1 to establish the allergen threshold dose and a second confirmatory CPT performed at visit 2. Eye symptom assessments for itching (evaluated by patient) and conjunctival redness (evaluated by physician) were performed 5 and 10 minutes after CPT using a 5-point scale (from 0 = none to 4+ = severe). Qualified patients were randomized to receive one drop of AZE (0.015 mg of azelastine hydrochloride) in one eye and one drop of placebo in the other eye 20 minutes before CPT at visit 3 (onset) and 8 or 10 hours before CPT at visit 4 (duration).

MAIN OUTCOME MEASURES

Individual severity scores for itching (evaluated by patient) and conjunctival redness (evaluated by physician) for each eye at 3, 5, and 10 minutes after CPT at visits 3 and 4 using a 5-point scale (0 = none to 4+ = very severe).

RESULTS

Each of the 80 randomized patients completed the trial. Mean itching and conjunctival redness scores at visit 3 (onset) were significantly lower (P: < 0.001) in the AZE-treated eyes than in the placebo-treated eyes. At visit 4 (duration), mean itching and conjunctival redness scores (P: </= 0.003) for the 8-hour group and mean itching scores (P: </= 0.001) for the 10-hour group were significantly lower in the AZE-treated eyes than in the placebo-treated eyes. Significant differences in mean tearing and chemosis severity scores were also seen at visit 3 (onset) and visit 4 (duration) in the AZE-treated eyes when compared with the placebo-treated eyes. Treatment with AZE was well tolerated.

CONCLUSIONS

Therapy of experimentally induced allergic conjunctivitis with AZE was highly effective, with an onset of action seen within 3 minutes and a duration of effect of at least 8 to 10 hours.

The placebo effect

Placebos have been traditionally regarded as deceptive therapies and have not been understood in the broader context of social symbols and of interpersonal factors that surround the healing process itself. Although the power of inert substances to heal is well recognized, the placebo effect also influences the outcome of conventional therapies. The role of the placebo in modern medicine is poorly defined because of a lack of a common understanding of what the placebo effect is and because of the negative connotions associated with its use. The response rate to placebo varies by illness. The natural course of disease and patient or physician bias can be misinterpreted as a placebo response. In research, the placebo effect is therapeutic noise to be removed by placebo-controlled trials. Few studies are designed to measure the placebo response rate directly. Placebos are a reminder of how little is known about mind-body interaction. The placebo effect may be one of the most versatile and underused therapeutic tools at the disposal of physicians.