piperidines and pemirolast

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

To evaluate the efficacy of a combined therapy with levocabastine hydrochloride ophthalmic suspension and pemirolast potassium ophthalmic solution compared to single therapy with levocabastine hydrochloride ophthalmic suspension alone.. Thirty-two allergic conjunctivitis patients were randomized to combined-treatment (n = 15) or single-treatment groups (n = 17). The improvement of subjective symptoms as well as objective findings were evaluated.. The degree of improvement was significantly higher in the combined-treatment group for lacrimation (p = 0.008) among the subjective symptoms, for conjunctival edema (p = 0.030), eyelid edema (p = 0.032) and conjunctival papilla formation(p = 0.040) among the objective findings.. Both objective assessments and subjective symptoms of allergic conjunctivitis showed the greatest improvements when patients were treated with combined therapy as compared to single-agent therapy. The enhanced benefits of combined therapy may result from these agents having different mechanisms of action.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Child; Conjunctivitis, Allergic; Drug Therapy, Combination; Eosinophils; Female; Histamine H1 Antagonists, Non-Sedating; Humans; Leukocyte Count; Male; Middle Aged; Ophthalmic Solutions; Piperidines; Pyridines; Pyrimidinones; Treatment Outcome

The effect of the simultaneous use of 0.025% levocabastine hydrochloride eye drops (levocabastine) and 0.1% pemirolast potassium ophthalmic solution (pemirolast) on experimental allergic conjunctivitis in rats was investigated. Levocabastine and pemirolast significantly inhibited allergic conjunctivitis compared with the control group when separately administered. In addition, the simultaneous use of both drugs inhibited allergic conjunctivitis more potently than the original activity of levocabastine or pemirolast. Furthermore, the simultaneous use of levocabastine and pemirolast also significantly inhibited increased vascular permeability induced by antigen compared with levocabastine or pemirolast alone, respectively. Levocabastine and pemirolast inhibited histamine release from the rat conjunctiva in correlation with a decrease in histamine content in tears. When levocabastine and pemirolast were simultaneously applied to the eyes, histamine release from the conjunctiva was greater than for the original activities of both drugs. Similar to histamine release from the conjunctiva, the histamine content in tears induced by the simultaneous use of both drugs was significantly decreased compared with levocabastine and pemirolast alone, respectively. A potentiating effect induced by the simultaneous use of levocabastine and pemirolast may be attributable to the antihistaminic activity of levocabastine and histamine release inhibition by levocabastine and pemirolast.

Topics: Animals; Conjunctivitis, Allergic; Drug Synergism; Drug Therapy, Combination; Histamine Release; Male; Piperidines; Pyridines; Pyrimidinones; Rats; Rats, Wistar