In vitro effects of preserved and unpreserved anti-allergic drugs on human corneal epithelial cells.

PURPOSE: Treatment with topical eye drops for long-standing ocular diseases like allergy can induce detrimental side effects. The purpose of this study was to investigate in vitro cytotoxicity of commercially preserved and unpreserved anti-allergic eye drops on the viability and barrier function of monolayer and stratified human corneal-limbal epithelial cells. METHODS: Cells were treated with unpreserved ketotifen solution, benzalkonium chloride (BAC)-containing anti-allergic drugs (ketotifen, olopatadine, levocabastine) as well as BAC alone. 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was used to determine cell viability. Effects of compounds on barrier function were analyzed measuring transepithelial electrical resistance (TEER) to determine paracellular permeability and rose bengal assays to evaluate transcellular barrier formation. RESULTS: The BAC-preserved anti-allergic formulations and BAC alone significantly reduced cell viability, monolayer cultures being more sensitive to damage by these solutions. Unpreserved ketotifen induced the least diminution in cell viability. The extent of decrease of cell viability was clearly dependent of BAC presence, but it was also affected by the different types of drugs when the concentration of BAC was low and the short time of exposure. Treatment with BAC-containing anti-allergic drugs and BAC alone resulted in increased paracellular permeability and loss of transcellular barrier function as indicated by TEER measurement and rose bengal assays. CONCLUSIONS: The presence of the preservative BAC in anti-allergic eye drop formulations contributes importantly to the cytotoxic effects induced by these compounds. Stratified cell cultures seem to be a more relevant model for toxicity evaluation induced on the ocular surface epithelia than monolayer cultures.

Application of the BCS biowaiver approach to assessing bioequivalence of orally disintegrating tablets with immediate release formulations.

The aim of this study was to compare the dissolution profiles of oral disintegrating tablets (ODTs) and immediate release (IR) formulations in order to experimentally validate the regulatory biowaiver scheme (BWS) for biopharmaceutical classification system (BCS) class III drugs. We examined six drugs that show clinical bioequivalence between the ODTs and IR formulations: taltirelin, olopatadine, droxidopa, famotidine, fexofenadine, and hydrochlorothiazide. The dissolution profiles of these drugs were evaluated using the compendium paddle apparatus at pH 1.2 and 6.8. Taltirelin and olopatadine showed very rapid dissolution and met the dissolution criteria in the BWS, whereas droxidopa, famotidine, fexofenadine, and hydrochlorothiazide did not. Furthermore, in the case of famotidine, fexofenadine, and hydrochlorothiazide, the ODTs and IR formulations showed dissimilar dissolution profiles. The dose-to-solubility ratio (D:S) of these drugs was larger than that of the other drugs. The results of this study suggest that extension of the BCS-BWS to ODTs and IR formulations of BCS class III drugs is appropriate. Furthermore, for BCS class III drugs with relatively high D:S, clinical bioequivalence would be achievable even when two formulations showed different dissolution profiles in vitro.

Stevens-Johnson syndrome following use of metronidazole in a dental patient.

Metronidazole alone rarely causes Stevens-Johnson syndrome (SJS). We present a case of an elderly male patient who, following metronidazole use, developed neurological symptoms followed by pain and blisters on both soles, erythema of face and neck, scrotal itching and erosion, and hemorrhagic encrustation around the lips and oral mucous membrane. Initial neurological symptoms followed by mucocutaneous manifestation of SJS following metronidazole use is probably a new presentation of this case.

Comparison of preservative-free ketotifen fumarate and preserved olopatadine hydrochloride eye drops in the treatment of moderate to severe seasonal allergic conjunctivitis.

PURPOSE: To compare preservative-free ketotifen 0.025% ophthalmic solution to olopatadine 0.1% ophthalmic solution in with the treatment of seasonal allergic conjunctivitis (SAC) in clinical practice. METHODS: This was a comparative, randomised, investigator-masked, pilot clinical study in adult patients with documented history of SAC and presenting with moderate to severe itching and conjunctival hyperemia. Eligible patients initiated either ketotifen or olopatadine treatment at a dose of one drop twice daily for 28days. The resolution of ocular signs and symptoms was assessed on day 7 and day 28. Itching was also assessed within 15minutes following the first instillation (day 0). Conjunctival impression cytology was performed at each visit to assess the evolution of ICAM-1 expression (day 0, 7 and 28). RESULTS: Seventy-five patients were randomised (ketotifen: 38 patients; olopatadine: 37 patients). At day 28, the composite score for primary criteria (itching, tearing, and conjunctival hyperemia) improved from 6.8±1.2 to 0.9±1.0 in the Ketotifen group, without statistically significant difference between treatment groups (P=0.67). There was no relevant difference between treatment groups in other efficacy parameters, except a trend for a more rapid resolution of conjunctival hyperemia in the Ketotifen group. Both drugs were well tolerated, with a trend for a better tolerability reported by patients on ketotifen compared to those on olopatadine at day 7 (P=0.054). CONCLUSIONS: A rapid and comparable improvement in SAC was achieved after 28days of treatment with both preservative-free ketotifen and preserved olopatadine ophthalmic solutions, with a slightly better ocular tolerance with unpreserved ketotifen 0.025% eye drops.

Comparative evaluation of olopatadine 0.01% combined fluorometholone 0.1% treatment versus olopatadine 0.01% combined ketorolac 0.4% treatment in patients with acute seasonal allergic conjunctivitis.

PURPOSE: To evaluate the therapeutic effects of low-effective steroid fluorometholone 0.1% and non-steroidal anti-inflammatory ketorolac 0.4% when concomitantly used with olopatadine 0.01% in relieving clinical signs and symptoms of acute seasonal allergic conjunctivitis (SAC). METHODS: In this randomized, placebo-controlled, multi-center study, 104 eyes of 52 patients with the diagnosis of SAC were conducted. The patients were assigned into two groups to receive either olopatadine and fluorometholone one eye and placebo in the contralateral eye or olopatadine and ketorolac one eye and placebo in the contralateral. The clinical signs (chemosis, mucus secretion, eyelid edema) and symptoms (itching, redness, tearing, burning) of the patients were evaluated by summing up the scores using a 3-point scale. Results were analyzed by Mann-Whitney U test, p values less than 0.05 were defined as significant. RESULTS: All parameters were improved less amount on the first day of the treatment in both groups, however, significant reduction in clinical signs and symptoms were seen on the 10th day compared with those receiving placebo. Fluorometholone was found superior to ketorolac in reducing redness, mucus secretion, chemosis and eyelid edema (p = 0.032 for redness, p = 0.028 for mucus secretion, p = 0.030 for chemosis, p = 0.042 for eyelid edema) and both drugs were similar in alleviating the symptoms itching, burning and tearing (p = 0.074 for itching, p = 0.064 for burning, p = 0.072 for tearing). CONCLUSIONS: Fluorometholone was better than ketorolac in relieving redness, chemosis, mucus secretion and eyelid edema when concomitantly used with olopatadine, however, these two drugs were found equal in attenuating the symptoms itching, burning and tearing.

Effect of intranasal fluticasone furoate and intraocular olopatadine on nasal and ocular allergen-induced symptoms.

BACKGROUND: Nasal allergen challenge (NAC) leads to a nasal ocular reflex, which is augmented by allergic inflammation. This study was designed to confirm our previous observation that an intranasal steroid inhibits the nasal ocular reflex and to show that histamine does not play an important role in the genesis of this reflex. METHODS: We performed a randomized, double-blind, double-dummy, placebo (PL)-controlled, four-way crossover trial in subjects with seasonal allergic rhinitis out of season. Subjects were randomized to receive 1 week pretreatment with intranasal PL and intraocular (PL/PL), intranasal PL and intraocular olopatadine (PL/OLO), intranasal fluticasone furoate (FF) and intraocular PL (FF/PL), and the combination (FF/OLO). Subjects then underwent NAC on 2 consecutive days. The number of sneezes and nasal and ocular symptoms were recorded, and levels of tryptase and histamine were measured in nasal lavages. RESULTS: NAC after PL/PL resulted in increase in symptoms, histamine, and tryptase after the challenge on the 2nd day. There was a reduction in eye symptoms on the 2nd day of challenge from 6.0 after PL/PL to 0 after FF/PL (p = 0.001), 2.5 after PL/OLO (p = 0.3), and 1.5 after FF/OLO (p = 0.003). Furthermore, there was no significant difference between the response after FF/PL versus FF/OLO and a significant difference between FF/PL and PL/OLO (p = 0.02). Levels of tryptase followed a similar trend. The number of eosinophils in nasal lavages on the 2nd day of challenge were also reduced by the treatment arms containing FF compared with PL. CONCLUSION: Our data confirm the existence of a nasal ocular reflex after NAC. OLO alone or the addition of OLO to FF does not impact ocular symptoms caused by the naso-ocular reflex, suggesting that mast cells are not activated to release histamine in the conjunctiva during this process.

A multicenter, double-blind, randomized, noninferiority comparison of 14 days' treatment with oral olopatadine 10 mg or cetirizine 10 mg in Chinese adults with cutaneous pruritus.

OBJECTIVES: To assess whether olopatadine hydrochloride (OH) was noninferior to cetirizine in the treatment of cutaneous pruritus (CP). PATIENTS AND METHODS: Patients with CP presenting at seven centers in China were randomly allocated to double-blind treatment with 5 mg of OH orally twice a day or cetirizine 10 mg orally once a day for 2 weeks. Patients were followed up on days 7 and 14. Noninferiority was predefined as a 20% maximum difference in the reduction of symptom score reducing indices (SSRI). Both intention-to-treat (ITT) and per-protocol populations were analyzed. RESULTS: 174 patients (86 receiving OH and 88 cetirizine) were included in the ITT population. In the ITT population, the mean reduction in SSRI was 0.640 ± 0.274 in the OH group and 0.603 ± 0.289 in the cetirizine group. The one-sided 97.5% CI (-0.047) met the criteria for noninferiority. Noninferiority was also demonstrated for SSRI in the per-protocol population, with reductions of 0.640 ± 0.271 with OH and 0.596 ± 0.287 with cetirizine (97.5% CI -0.043).The total effectiveness rate (TER) was similar in the OH (90.0%) and cetirizine (80.0%) groups. The corresponding one-sided 97.5% CI (-1.0%) also demonstrated noninferiority. The incidence of adverse events was 47.1% in the OH group and 41.4% in the cetirizine group (p = 0.453). CONCLUSION: The efficacy of OH was noninferior to that of cetirizine in controlling itching indicating that it can be considered as a clinically relevant alternative therapy to cetirizine for the management of CP in adult Chinese patients.

Double dose of cetirizine hydrochloride is effective for patients with urticaria resistant: a prospective, randomized, non-blinded, comparative clinical study and assessment of quality of life.

OBJECTIVE: An increased dose of the prescribed drug or a change of the drug is recommended in the treatment for the patients with urticaria refractory to the standard dose of antihistamines. Efficacy and safety of doubling the dose of cetirizine were compared with olopatadine in the patients with symptoms like wheal or itching, despite the treatment with the standard dose of cetirizine. METHODS: Cetirizine was administered at 10 mg once daily to 51 patients with urticaria for a mean of 10.1 ± 7.3 days (period A). Patients with inadequate responses were randomized to either cetirizine 20 mg once daily (dose-increase group) or olopatadine 5 mg twice daily (drug-change group) for a mean of 13.3 ± 8.3 days (Period B). The severity of wheal and itching, and the quality of life (QOL) measured by Skindex-16 were evaluated. RESULTS: In period A, an adequate response was obtained in 64.7% (33/51). Nine patients each with inadequate response were randomized to either the drug-change or dose-increase groups. A significant improvement was observed in the severity of wheal and itching in the dose-increase group in period B. The QOL was significantly improved in all sub-scales of Skindex-16. CONCLUSION: Doubling the dose of cetirizine may be efficacious to the patients with urticaria refractory to the regular dose of cetirizine.

[A 10-week safety and efficacy evaluation of olopatadine, 0.2% instilled twice-daily in patients with allergic conjunctivitis in Japan].

PURPOSE: Olopatadine hydrochloride ophthalmic solution, 0.2% (olopatadine 0.2%) is a multi-action agent approved in Japan for allergic conjunctivitis when used as a dose of 1 to 2 drops twice-daily. The objective of this study was to evaluate the long-term (10 weeks) safety and efficacy of olopatadine 0.2% in Japanese patients with allergic conjunctivitis when used as a dose of 2 drops twice-daily. SUBJECTS AND METHODS: This was a single-insititution, open-label, single-group study of symptomatic patients > or = 12 years of age with allergic conjunctivitis. RESULTS: A total of 110 Japanese patients were enrolled. From baseline to week 10, the mean (95% confidence interval) absolute changes were -2.4 (-2.7, -2.2) in ocular itching and the total hyperemia scores were -3.2 (-3.4, -2.9). Mean scores for all other efficacy variables were low at baseline (< or = 2.4) and decreased to < or = 0.6 by week 10. There were no serious adverse events. Mild eye irritation (1 patient) was the only treatment-related event. No safety concerns were identified in a review of the safety results. CONCLUSIONS: Based on this study, olopatadine 0.2% is generally safe, well tolerated and effective when instilled as 2 drops in both eyes twice-daily in Japanese patients with allergic conjunctivitis and is a useful new option for ocular allergy management.

The antagonism of histamine H1 and H4 receptors ameliorates chronic allergic dermatitis via anti-pruritic and anti-inflammatory effects in NC/Nga mice.

BACKGROUND: Although histamine H1 receptor (H1R) antagonists are commonly used to treat atopic dermatitis, the treatment is not always effective. The histamine H4 receptor (H4R) was recently described as important to the pruritus in dermatitis. Here, we investigated whether the combination of a H1R antagonist plus a H4R antagonist attenuates chronic dermatitis in NC/Nga mice. METHODS: Chronic dermatitis was developed by repeated challenges with picryl chloride on the dorsal back and ear lobes. The therapeutic effects of the H1R antagonist olopatadine and H4R antagonist JNJ7777120 on scratching and the severity of dermatitis were evaluated. In addition, the mechanisms responsible for the anti-allergic effects of H1R and/or H4R antagonism were examined using bone marrow-derived mast cells (BMMC) and keratinocytes. RESULTS: JNJ7777120 attenuated scratching behavior after a single administration and improved dermatitis, as assessed with clinical scores, pathology, and cytokine levels in skin lesions when administered repeatedly. These effects were augmented by combined treatment with olopatadine, having a similar therapeutic efficacy to prednisolone. JNJ7777120 inhibited dose-dependently the production of thymus and activation-regulated chemokine/CCL17 and macrophage-derived chemokine/CCL22 from antigen-stimulated BMMC. In addition, olopatadine reversed the histamine-induced reduction of semaphorin 3A mRNA in keratinocytes. CONCLUSION: Combined treatment with H1R and H4R antagonists may have a significant therapeutic effect on chronic dermatitis through the synergistic inhibition of pruritus and skin inflammation.

Loteprednol etabonate suspension 0.2% administered QID compared with olopatadine solution 0.1% administered BID in the treatment of seasonal allergic conjunctivitis: a multicenter, randomized, investigator-masked, parallel group study in Chinese patients.

BACKGROUND: Seasonal allergic conjunctivitis (SAC) is caused by seasonal allergens and usually manifests as ocular itching and bulbar conjunctival injection (redness). Treatment options for SAC include corticosteroids and dual-acting antihistamine and mast-cell stabilizers. OBJECTIVE: Our objective was to compare the efficacy and tolerability of loteprednol etabonate (LE), a C-20 ester-based corticosteroid, with those of olopatadine, a dual-acting antihistamine mast-cell stabilizer, in Chinese patients. METHODS: This was a multicenter, randomized, investigator-masked, parallel group study. Patients with acute SAC experiencing grade 4 ocular itching and grade 2 or higher bulbar conjunctival injection received either LE suspension 0.2% QID at 4-hour intervals or olopatadine solution 0.1% BID at 6- to 8-hour intervals bilaterally for 15 days. Primary efficacy end points included the change from baseline (CFB) in ocular itching and bulbar conjunctival injection at day 15. The primary analysis tested the noninferiority of LE suspension 0.2% to olopatadine solution 0.1%. Tolerability outcomes included the incidence of adverse events (AEs), biomicroscopy findings, visual acuity, and intraocular pressure. RESULTS: A total of 300 patients were randomly assigned, and 293 were included in the per-protocol population (LE, n = 147; olopatadine, n = 146). Mean (SD) CFB at day 15 in the LE and olopatadine treatment groups, respectively, was -3.74 (0.47) and -3.28 (0.91) for ocular itching and -1.91 (0.52) and -1.71 (0.59) for bulbar conjunctival injection. The 95% CI for the differences in CFB in ocular itching (-0.59 to -0.27) and bulbar conjunctival injection (-0.27 to -0.08) was less than the prespecified noninferiority limit of 0.3. Treatment differences in CFB were significantly better with LE compared with olopatadine for both end points (P ≤ 0.0006). Ocular AEs were few and similar between treatment groups. There were no clinically significant biomicroscopy or visual acuity findings, and no patient experienced a clinically significant increase in intraocular pressure (≥10 mm Hg). CONCLUSION: Results of this investigator-masked study with Chinese patients suggest LE suspension 0.2% was noninferior to olopatadine solution 0.1% for the treatment of SAC. Both LE suspension 0.2% and olopatadine solution 0.1% were well tolerated. ClinicalTrials.gov identifier: NCT01435460.

[A multicenter, double-masked, randomized evaluation of olopatadine 0.2% using the conjunctival allergen challenge model in Japanese patients with allergic conjunctivitis].

PURPOSE: Olopatadine hydrochloride ophthalmic solution, 0.2% (olopatadine 0.2%) is approved for allergic conjunctivitis when instilled twice-daily. The objective of this study was to evaluate the efficacy and safety of olopatadine 0.2% (instilled twice-daily) versus vehicle and olopatadine 0.1% (instilled 4-times daily) in Japanese patients with allergic conjunctivitis. METHODS: A multicenter, parallel-group, double-masked, randomized, conjunctival allergen challenge (CAC) study. Patients > or = 18 years of age with histories of allergic conjunctivitis were treated with either olopatadine 0.2% or olopatadine 0.1% in a single eye and the vehicle in the contralateral eye at 1 visit. RESULTS: Overall, 267 patients were enrolled. Olopatadine 0.2% was superior to its vehicle for ocular itching (p < 0.0001 at the time of observation) and marginally superior for total redness (p = 0.0543 at the time of observation). Olopatadine 0.2% was similar to olopatadine 0.1% for ocular itching at the time of observation. No trends were identified through a review of safety parameters. CONCLUSIONS: Olopatadine 0.2% (instilled twice-daily) is safe, well tolerated, superior to the vehicle, and similar to olopatadine 0.1% in preventing ocular itching. Olopatadine 0.2%, which can be instilled less often than olopatadine 0.1%, is a useful new option for allergic conjunctivitis in Japanese patients that could potentially result in better treatment compliance.

Effects of single therapeutic doses of promethazine, fexofenadine and olopatadine on psychomotor function and histamine-induced wheal- and flare-responses: a randomized double-blind, placebo-controlled study in healthy volunteers.

Since most first-generation antihistamines have undesirable sedative effects on the central nervous systems (CNS), newer (second-generation) antihistamines have been developed to improve patients' quality of life. However, there are few reports that directly compare the antihistaminic efficacy and impairment of psychomotor functions. We designed a double-blind, placebo controlled, crossover study to concurrently compare the clinical effectiveness of promethazine, a first-generation antihistamine, and fexofenadine and olopatadine, second-generation antihistamines, by measuring their potency as peripheral inhibitors of histamine-induced wheal and flare. Further, we investigated their sedative effects on the CNS using a battery of psychomotor tests. When single therapeutic doses of fexofenadine (60 mg), olopatadine (5 mg) and promethazine (25 mg) were given in a double-blind manner to 24 healthy volunteers, all antihistamines produced a significant reduction in the wheal and flare responses induced by histamine. In the comparison among antihistamines, olopatadine showed a rapid inhibitory effect compared with fexofenadine and promethazine, and had a potent effect compared with promethazine. In a battery of psychomotor assessments using critical flicker fusion, choice reaction time, compensatory tracking, rapid visual information processing and a line analogue rating scale as a subjective assessment of sedation, promethazine significantly impaired psychomotor function. Fexofenadine and olopatadine had no significant effect in any of the psychomotor tests. Promethazine, fexofenadine and olopatadine did not affect behavioral activity, as measured by wrist actigraphy. These results suggest that olopatadine at a therapeutic dose has greater antihistaminergic activity than promethazine, and olopatadine and fexofenadine did not cause cognitive or psychomotor impairment.

Pharmacokinetic evaluation of olopatadine for the treatment of allergic rhinitis and conjunctivitis.

INTRODUCTION: Olopatadine hydrochloride is an antihistamine and mast cell stabilizer available in three forms, including oral, intranasal and ocular preparations. Most of the practical applications focus on the use of olopatadine for the treatment of allergic rhinitis and conjunctivitis via intranasal and ocular routes. AREAS COVERED: This article was formed from a comprehensive literature search with information taken from meta-analyses, systematic reviews, treatment guidelines and clinical studies on children and adults. Articles that have been selected evaluate the use of intranasal and ocular antihistamines and their role in allergic rhinitis and conjunctivitis. EXPERT OPINION: Olopatadine is significantly more effective than placebos in alleviating the symptoms of allergic rhinitis and conjunctivitis. Olopatadine is a viable alternative and addition to the mainstay therapy of these conditions with intranasal steroids and oral antihistamines. The compliance of the patients would be improved if a once-per-day formulation of olopatadine was developed for intranasal application. The future treatments of allergic rhinitis will probably involve a combination of intranasal antihistamine and steroid because clinical trials have demonstrated an improved efficacy without a significant increase in adverse effects.

Olopatadine 0.6% nasal spray protects from vasomotor challenge in patients with severe vasomotor rhinitis.

BACKGROUND: Vasomotor rhinitis (VMR) is a hypersensitivity syndrome with heightened reactivity to environmental triggers. METHODS: Twenty-two patients with severe VMR were treated nasally with either normal saline or 0.6% olopatadine and challenged nasally with a hyperosmolar mannitol solution. RESULTS: Treatment with 0.6% olopatadine resulted in an improvement in instantaneous nasal symptom scores at 5 and 30 minutes (p < 0.01) compared with baseline and at 30 minutes after hyperosmolar challenge compared with saline-pretreated individuals (p < 0.01). There was also an improvement in nasal peak inspiratory flow rate at 30 minutes after hyperosmolar challenge compared with saline-pretreated individuals (p < 0.01). CONCLUSION: In this patient population 0.6% olopatadine appears to be efficacious in symptom reduction in VMR and protects from hyperosmolar challenge.

Comprehensive report of olopatadine 0.6% nasal spray as treatment for children with seasonal allergic rhinitis.

Allergic rhinitis (AR) is highly prevalent in children. Olopatadine, 0.6% nasal spray (olopatadine) is approved for the relief of seasonal allergic rhinitis (SAR) symptoms in children 6 years of age and older. The objective of this study is to provide a comprehensive report of all clinical studies conducted with olopatadine in children with SAR. A pooled analysis was conducted of 2 randomized, double-blind, 2-week, IRB-approved studies that compared olopatadine with placebo (1 spray/nostril twice-daily) in patients 6-11 years of age with SAR. Assessments included the reflective total nasal symptom score (rTNSS) and total ocular symptom score (rTOSS), the Pediatric Rhinoconjunctivitis Quality-of-Life Questionnaire (PRQLQ), and the Caregiver Treatment Satisfaction Questionnaire for Allergic Rhinitis (CGTSQ-AR). Safety results were reported for these studies in combination with a pediatric pharmacokinetic study. Olopatadine was superior to placebo for mean decrease in rTNSS (p = 0.0012) and rTOSS (p = 0.0094), mean decrease in overall PRQLQ score (p = 0.0003), and mean summary CGTSQ AR score (p = 0.0013); (n = 944). The most frequently reported treatment-related events in the olopatadine group were epistaxis and dysgeusia (bad taste) (n = 1,046). For SAR treatment in patients 6-11 years of age, olopatadine was superior to placebo in reducing the symptoms of SAR, improving quality of life, and satisfying caregivers. Olopatadine is a safe and effective treatment for SAR patients as young as 6 years of age and it has been demonstrated to reduce disease impact on the lives of these children and their families.

Comparison of effects of alcaftadine and olopatadine on conjunctival epithelium and eosinophil recruitment in a murine model of allergic conjunctivitis.

BACKGROUND: Antihistamines constitute the first line of therapy for allergic conjunctivitis, and are safe and effective in relieving the signs and symptoms of ocular allergy. Despite this, they are less effective than some other drugs in relieving delayed symptoms of allergic conjunctivitis. Recent evidence suggests that changes in the conjunctival epithelium may underlie aspects of delayed reactions. In this study we compared two antihistamines, olopatadine and alcaftadine, for their ability to modify epithelial cell changes associated with allergic conjunctivitis at time points selected to reflect late-phase reactions. METHODS: Studies employed a modified conjunctival allergen challenge model. Sensitized mice were challenged with topical allergen with or without drug treatments. Treatment groups were assayed for acute-phase (15 minutes) and delayed-phase (24 hours) responses. Groups were scored for allergy symptoms (redness, itch, tearing, and edema) and for conjunctival mast cell numbers. Delayed-phase groups were also examined for eosinophil numbers and for tight junctional protein expression. RESULTS: Olopatadine-treated and alcaftadine-treated animals had similar efficacy profiles and mast cell numbers, suggesting both were effective at ameliorating symptoms of the acute phase. In contrast, alcaftadine-treated animals had significantly lower conjunctival eosinophil infiltration than either controls or olopatadine-treated animals. Allergen challenge caused a significant decrease in expression of the junctional protein, ZO-1, and this decrease was prevented by alcaftadine but not by olopatadine. CONCLUSION: Alcaftadine displays therapeutic properties beyond its antihistamine action. These include an ability to reduce conjunctival eosinophil recruitment, and a protective effect on epithelial tight junction protein expression.

Olopatadine hydrochloride inhibits capsaicin-induced flare response in humans.

Capsaicin, a vanilloid, has the potential for releasing substance P (SP) from sensory nerves. Topical application of capsaicin induces a flare response in the skin. However, it has not been clarified whether the release of SP is involved in the process of flare response or not. A potent antihistamine drug, olopatadine hydrochloride, is known to have inhibitory action against the release of SP. We examined the effects of olopatadine (at a dose of 5 mg) on skin reaction induced by topical application of capsaicin in 10 healthy subjects. The scores of capsaicin-induced flare responses after olopatadine administration were significantly lower at 30 min than at baseline. Our findings suggest that olopatadine hydrochloride could inhibit capsaicin-induced flare responses.

Pre-seasonal treatment with topical olopatadine suppresses the clinical symptoms of seasonal allergic conjunctivitis.

PURPOSE: To evaluate the effectiveness of pre-seasonal treatment with topical olopatadine on the reduction of clinical symptoms of seasonal allergic conjunctivitis (SAC). DESIGN: Prospective interventional case series. METHODS: Eleven patients with SAC received topical olopatadine in one eye at least two weeks before the onset of allergy symptoms, and the other eye served as the control. After the onset of allergic conjunctivitis, both eyes were treated with topical olopatadine. Visual analogue scale (VAS), which evaluated the subjective symptoms of ocular allergy, and the tear levels of histamine and substance P were measured up to six weeks. RESULTS: At the onset of allergy symptoms, the VAS score in the pretreatment eyes was statistically significantly lower than that in the control eyes. The VAS score in the control eyes decreased with time but did not decrease to the level seen in the pretreatment eyes until four weeks later. The tear level of substance P at the onset of allergy symptoms was significantly suppressed in the pretreatment eyes, while the level of histamine was not suppressed. Alteration of the VAS scores in the pretreatment eyes significantly correlated with the level of substance P, but not of histamine. CONCLUSIONS: To suppress clinical symptoms in patients with SAC, pre-seasonal treatment with topical olopatadine is effective. The effectiveness of treatment correlates with the tear level of substance P.