alcaftadine and Pruritus

To address the current trends of therapeutic mechanisms for treatment of allergic conjunctivitis (AC), based on topical antihistamines and mast cell stabilizers (MCS).. The antihistamine drug alcaftadine has H4 receptor inverse agonism, anti-inflammatory and MCS activities. The antihistamines levocabastine and azelastine are more effective than placebo in treatment of AC symptoms in randomized controlled trials (RCTs). The topical dual-action antihistamines/MCS olopatadine, azelastine, ketotifen, and epinastine are commonly used in Europe and in the United States for mild subtypes of AC. For the main symptoms of AC, ocular itch and conjunctival hyperemia, epinastine 0.05% was superior to placebo, but equal or more effective than olopatadine 0.1%, while the later was more effective than ketotifen. High concentration olopatadine 0.77% had longer duration of action, better efficacy on ocular itch, and a similar safety profile to low-concentration olopatadine 0.2%. The new formulas of topical dual-action agents present longer duration of action, leading to a decreased frequency of use.. The topical dual-action agents are the most effective agents treating signs and symptoms of mild forms of AC. There is superiority to the high-concentration olopatadine drug over other agents on ocular itch, with prolonged effect when used once-daily.

Topics: Administration, Ophthalmic; Anti-Allergic Agents; Benzazepines; Conjunctivitis, Allergic; Cromolyn Sodium; Dibenzazepines; Histamine Antagonists; Humans; Hyperemia; Imidazoles; Ketotifen; Nedocromil; Olopatadine Hydrochloride; Phthalazines; Piperidines; Pruritus; Pyridines; Pyrimidinones

Alcaftadine (Lastacaft®; Allergen, Inc.) is a broad-spectrum antihistamine displaying a high affinity for histamine H1 and H2 receptors and a lower affinity for H4 receptors. It also exhibits modulatory action on immune cell recruitment and mast cell stabilizing effects. The authors reviewed all available English-language literature characterizing the efficacy, safety and pharmacokinetic profile of alcaftadine ophthalmic solution. In the studies reviewed, alcaftadine was more effective than placebo and at least as effective as olopatadine 0.01% in preventing ocular itching at 15 minutes and at 16 hours after administration. Alcaftadine 0.025% ophthalmic solution has been approved by the U.S. Food and Drug Administration for prevention of itching associated with allergic conjunctivitis in patients over 2 years of age. Comparative efficacy data of alcaftadine to other ocular antihistamine/mast cell stabilizers are limited.

Topics: Administration, Topical; Animals; Benzazepines; Conjunctivitis, Allergic; Drug Interactions; Humans; Imidazoles; Ophthalmic Solutions; Pruritus; Randomized Controlled Trials as Topic; Receptors, G-Protein-Coupled; Receptors, Histamine; Receptors, Histamine H4

The efficacy and safety of the once-daily topical ophthalmic solutions, alcaftadine 0.25% and olopatadine 0.2%, in preventing ocular itching associated with allergic conjunctivitis were evaluated.. Pooled analysis was conducted of two double-masked, multicenter, active- and placebo-controlled studies using the conjunctival allergen challenge (CAC) model of allergic conjunctivitis. Subjects were randomized 1:1:1 to receive alcaftadine 0.25%, olopatadine 0.2%, or placebo. The primary efficacy measure was subject-evaluated mean ocular itching at 3 min post-CAC and 16 h after treatment instillation. Secondary measures included ocular itching at 5 and 7 min post-CAC. Ocular itch was determined over all time points measured (3, 5, and 7 min) post-CAC and the proportion of subjects with minimal itch (itch score<1) and zero itch (itch score=0) was also assessed.. A total of 284 subjects were enrolled in the two studies. At 3 min post-CAC and 16 h after treatment instillation, alcaftadine 0.25% achieved a significantly lower mean itch score compared with olopatadine 0.2% (0.50 vs. 0.87, respectively; P=0.0006). Alcaftadine demonstrated a significantly lower mean itch score over all time points compared with olopatadine (0.68 vs. 0.92, respectively; P=0.0390); both alcaftadine- and olopatadine-treated subjects achieved significantly lower overall mean ocular itching scores compared with placebo (2.10; P<0.0001 for both actives). Minimal itch over all time points was reported by 76.1% of alcaftadine-treated subjects compared with 58.1% of olopatadine-treated subjects (P=0.0121). Treatment with alcaftadine 0.25% and olopatadine 0.2% was safe and well tolerated; no serious adverse events were reported.. Once-daily alcaftadine 0.25% ophthalmic solution demonstrated greater efficacy in prevention of ocular itching compared with olopatadine 0.2% at 3 min post-CAC (primary endpoint), and over all time points, 16 h post-treatment instillation. Alcaftadine and olopatadine both provided effective relief compared with placebo and were generally well tolerated.

Topics: Adult; Allergens; Anti-Allergic Agents; Benzazepines; Conjunctivitis, Allergic; Double-Blind Method; Drug Monitoring; Female; Humans; Imidazoles; Male; Middle Aged; Olopatadine Hydrochloride; Ophthalmic Solutions; Patient Outcome Assessment; Pruritus

The purpose of this study was to evaluate the safety and clinical efficacy of alcaftadine 0.25% ophthalmic solution, a new topical anti-allergic agent for the prevention of the signs and symptoms of allergic conjunctivitis induced by conjunctival allergen challenge (CAC).. This two-arm, double-masked, multi-center, placebo-controlled Phase III study (NCT00889330) enrolled healthy volunteers (N = 58) with a history of allergic conjunctivitis. Subjects ≥10 years of age with a reproducible, positive reaction to a CAC were randomized to receive either one drop of alcaftadine 0.25% ophthalmic solution bilaterally or vehicle bilaterally. After 16 hours (Visit 3) and 15 minutes (Visit 4), a CAC was performed and ocular and nasal symptoms of allergy were graded over a 20-minute period. Clinical and statistical significance were evaluated.. The primary endpoints were ocular itching and conjunctival redness. The secondary endpoints were all other signs and symptoms of allergic conjunctivitis. Visual acuity, slit lamp biomicroscopy and adverse event reporting were the predetermined safety measures.. Alcaftadine was effective in the prevention of ocular itching based on both clinically relevant and statistically significant differences compared with vehicle (placebo). Alcaftadine significantly reduced conjunctival redness, and almost all other allergic signs and symptoms at both 15 minutes and 16 hours after drug administration. No significant safety issues were reported. Between-group differences in ocular itching were higher 16 hours after drug administration than at 15 minutes after drug administration.. With an onset of action within 3 minutes and a duration of action of at least 16 hours, the statistically and clinically significant effect of alcaftadine 0.25% on itching make it an important addition to therapy for ocular allergy. Additional studies are warranted to better understand the mechanisms affording a fast onset and prolonged duration of action.

Topics: Adult; Benzazepines; Conjunctivitis, Allergic; Double-Blind Method; Female; Histamine Antagonists; Humans; Imidazoles; Male; Middle Aged; Ophthalmic Solutions; Osmolar Concentration; Placebos; Pruritus; Time Factors; Treatment Outcome; Young Adult

Topics: Benzazepines; Conjunctivitis, Allergic; Histamine H1 Antagonists; Humans; Imidazoles; Pruritus