Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0033774 (pruritus)
 14,546 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of nonsteroidal anti-inflammatory drugs (NSAIDs) on experimental allergic conjunctivitis, induced by ocular challenge with antigen in actively sensitized guinea pigs, were investigated. NSAIDs reduced the increase in prostaglandin D2 (PGD2) and E2 (PGE2) in the ocular lavage fluid. The inhibition of NSAIDs to these increases was approximately 90%-95%. NSAIDs also lowered itch-scratch response (ISR) to approximately one-third to one-half of the vehicle-treated group. However, these drugs scarcely affected plasma exudation in the conjunctiva. Ketotifen, an H1 histamine receptor antagonist, inhibited both pathophysiological changes (inhibition: 70%-80%). However, this drug was less efficacious than NSAIDs in reducing PGD2 and PGE2 levels. Moreover, topical administration of histamine induced ISR and plasma exudation; in contrast, PGD2 induced ISR exclusively. These results suggest that a part of antigen-induced ISR may be attributable to PGs. However, PGs may not play a key role in plasma exudation; other mediators such as histamine may be involved.
 ...
PMID:Effects of nonsteroidal anti-inflammatory drugs on experimental allergic conjunctivitis in Guinea pigs. 1473 14

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 serious vision threatening forms of ocular allergy which affect the cornea, such as atopic keratoconjunctivitis. The pathogenesis of allergic conjunctivitis involves a complex mechanism which centers around IgE-mediated mast cell degranulation and release of multiple preformed and newly formed inflammatory mediators. The diagnosis of allergic conjunctivitis is usually a clinical one which can be made based on a thorough history and careful examination. Treatment of ocular allergy should begin with conservative measures including allergen avoidance, environmental control, ocular irrigation and cold compresses. Pharmacotherapy of allergic conjunctivitis consists of several classes of drugs. Antihistamines are widely used to treat mild conditions such as seasonal and perennial conjunctivitis and potent new agents such as levocabastine and emedastine are now available. Mast cell stabilizers such as sodium cromoglycate are both safe and effective and are commonly used in ocular allergy. More effective mast cell stabilizers such as nedocromil, lodoxamide and olopatadine are now being used. Nonsteroidal antiinflammatory drugs have demonstrated only limited efficacy and, as such, are not widely used. Topical steroids are very effective in treating signs and symptoms but are reserved for only refractory cases due to their serious side effects. Loteprednol and rimexelone are newer corticosteroids which reportedly have less of an effect on intraocular pressure. Cyclosporine has recently been shown to be highly effective in cases of vernal keratoconjunctivitis and atopic keratoconjunctivitis while producing no adverse effects.
 ...
PMID:Ocular allergic disease. 1474 64

The present study was performed to develop a new model for evaluating itching associated with allergic conjunctivitis in rats. Repeated topical application of antigen caused an increase in eye scratching behavior in sensitized animals, and a significant difference was observed from days 21 to 42. Almost the same findings were observed in allergic symptoms, hyperemia and edema. Instillation of histamine also resulted in an increase in eye scratching behavior. The sensitivity to histamine in eye scratching behavior was increased by topical antigen application for 42 days after sensitization. In addition, the number of conjunctival eosinophils was significantly increased by repeated topical antigen application from days 21 to 42 in sensitized rats. Some anti-allergic drugs such as olopatadine (H1 antagonist), cetiridine (H1 antagonist) and ramatroban (thromboxane A2 (TXA2) antagonist) caused an inhibition of eye scratching behavior induced by topical sensitization in a dose-related manner. However, zafirlukast (cys-LT antagonist) caused no significant inhibition even at a dose of 30 mg/kg. The findings in present model of itching in allergic conjunctivitis were mainly through histamine H1-activity, and thromboxane A2 receptors were also involved in the response.
 ...
PMID:A chronic model for evaluating the itching associated with allergic conjunctivitis in rats. 1497 64

Pharmacologic studies examined the potential of a solution containing olopatadine to maintain and extend antiallergic efficacy after single topical ocular drop administration over 24 hours. Results of these preclinical experiments conducted in guinea pigs indicated that olopatadine 0.2% (wt/vol) solution was significantly effective 24 hours after dosing. This concentration of olopatadine provided significantly more efficacy than Patanol (olopatadine 0.1%) 24 hours after administration while being as effective as Patanol (olopatadine 0.1%) 5 minutes after administration. Results from a human conjunctival allergen challenge trial in sensitive subjects confirmed clinical efficacy of olopatadine 0.2% solution over 24 hours. When individuals were challenged with antigen at onset, 16 and 24 hours after drug administration onto the eye, significant reductions were observed in the scores for active drug as compared with placebo for pruritus (77, 77, and 61%), conjunctival redness (35, 28, and 20%), and chemosis (53, 41, and 31%), respectively. These data suggest that topically applied olopatadine 0.2% solution will be an effective once-a-day therapy for allergic conjunctivitis.
 ...
PMID:Preclinical and clinical antiallergic effect of olopatadine 0.2% solution 24 hours after topical ocular administration. 1505 65

Platelet-activating factor (PAF) plays important roles in allergic reactions. In particular, there are many concerns about PAF, eosinophils, and the chronicity of allergic diseases. The purpose of the present studies is to elucidate the role of PAF in eosinophil activation at conjunctiva and to confirm the efficacy of Apafant (a potent PAF antagonist) ophthalmic solution in chronic experimental allergic conjunctivitis. Guinea pigs were actively immunized and allergic conjunctivitis was induced by repetitive instillation of 2.5% ovalbumin. PAF solution was topically applied and eosinophil activation was assessed by measuring the eosinophil peroxidase (EPO) activity in the tear fluid. Itch-scratching episodes and clinical symptoms scores were evaluated in the repetitive challenge conjunctivitis. From the instillation of PAF solution into guinea pig eyes, which were in a state of chronic allergic conjunctivitis, a significant increase in EPO activity was observed, and this increase was inhibited by pre-treatment with Apafant. In the repetitive challenge model, the animals treated with Apafant ophthalmic solution showed a significant reduction of clinical symptoms and the itch-scratch response in both the first and the second challenges. PAF has an activity, that induces mediator release from eosinophils in the conjunctival tissues and may be involved in the chronic phase of allergic conjunctivitis.
 ...
PMID:Apafant, a potent platelet-activating factor antagonist, blocks eosinophil activation and is effective in the chronic phase of experimental allergic conjunctivitis in guinea pigs. 1528 29

Intranasal corticosteroids (IC) are most commonly prescribed to treat allergic rhinitis (perennial and seasonal). There are now many IC available to treat rhinitis, all effective on nasal obstruction, rhinorrhea, sneezing, itching and post-nasal drip. IC are superior to oral antihistamines for the relief of all nasal symptoms; however, antihistamines are first line therapy if allergic conjunctivitis coexists. At present the data do not support the use of IC in the management of otitis media with effusion (OME), nasal polyposis and sinusitis, but when topical IC are administered together with antibiotic therapy they facilitate a more rapid improvement of symptoms.
 ...
PMID:Effectiveness of intranasal corticosteroids. 1531 83

Ocular allergy affects > 20% of the general population and many therapeutic preparations are available to individuals experiencing the most common forms--seasonal and perennial allergic conjunctivitis. 0.1% Olopatadine topical ophthalmic solution is currently approved for the treatment of allergic signs and symptoms in patients > or = 3 years of age. Olopatadine is available in Europe as Opatanol) and in > 30 other countries as Patanol. It inhibits mast cell degranulation and antagonises histamine receptors to manage the itching, redness, chemosis, tearing and lid swelling of the ocular allergic reaction, and its mast cell stabilising ability has been demonstrated both in vitro (using human conjunctival mast cells) and in vivo (human clinical experience). This article reviews both the laboratory and clinical information available on olopatadine, prefaced by a discussion of the current understanding of the ocular allergic reaction and followed by the future implications for this compound. Both laboratory and clinical studies have established the efficacy, safety and comfort of olopatadine in several study design models and comparisons to other antiallergy medications. The application of olopatadine, specifically in the management of lid swelling, an allergic sign recalcitrant to therapy and nasal allergic symptoms has also been established. In the future, a new formulation containing 0.2% olopatadine exhibits a duration of action up to 24 h, supporting once-daily dosing.
 ...
PMID:A review of olopatadine for the treatment of ocular allergy. 1533 Jul 35

Atopic conditions include allergic rhinitis, atopic eczema, allergic conjunctivitis and asthma. Doctors and patients can choose from a variety of antiallergy medications, testifying that no one medication will suffice to treat all symptoms and that each has a different side-effect profile. Antiallergy medications target histamine receptors, as histamine release contributes to the unpleasant symptoms of itching, tearing, runny nose and skin urticaria. The ideal antihistamine would control the symptoms of atopic disease but cause very few side effects. Traditionally, unwanted effects include drowsiness and somnolence due to CNS depression, and digestive tract problems such as loss of appetite, nausea, vomiting and constipation or diarrhea. Some antihistamines also have anticholinergic effects that are mediated by muscarinic receptors. These atropine-like actions, which can affect the cardiovascular system, are sufficiently prominent in some drugs to be manifest during clinical usage. Epinastine hydrochloride minimally penetrates the blood/brain barrier and has almost no effect on the muscarinic receptors. This drug is marketed as having very few CNS-depressant side effects, few drug interactions and gastrointestinal side effects, and a low risk of cardiotoxicity.
 ...
PMID:Epinastine hydrochloride for atopic disease. 1551 Feb 39

A group of 25 patients with signs of seasonal allergic conjunctivitis treated during the period of 2 to 6 month with ketotifen fumarate 0.05% eye drops 2-3 times daily (Zaditen eye drops, Novartis Ophthalmic, AG, Switzerland) is described here. As subjective symptoms of itching, stinging, tearing, and mucous discharge were observed and evaluated, as well as objective signs of hyperemia of the conjunctiva and hypertrophy of the tarsal papillae. Similarly the onset of action, duration time, and toleration of the drug were assessed. Subjective symptoms disappeared after 10 days of treatment duration in 60% to 80% patients, after two months of treatment were present in the range 0% to 20%. Objective signs diminished after 10 days of treatment in 60%-72% patients, and after 2 months in 72% to 96% of patients. Hypertrophy of papillae of the tarsal conjunctiva did not totally disappear even after 6 month of treatment with ketotifen fumarate eye drops. Onset of action in all patients was 20 minutes or less, the duration of action was in the range of 8-13 hours. The drug was found as a good tolerable by all patients. Sixteen per cent of patients felt some burning following the instillation. The study states that ketotifen fumarate 0.05% eye drops are effective in a monotherapy of seasonal allergic conjunctivitis. Due to its multiple action, the drug prevents the allergic reaction as well. Subjective symptoms are influenced faster and more effective than the objective signs. The treatment of objective signs needs prolonged use of these drops.
 ...
PMID:[Ketotifen fumarate (Zaditen) eye drops in the treatment of seasonal allergic conjunctivitis]. 1556 25

Allergic conjunctivitis can seriously disrupt children's daily activities. This study assessed the efficacy (onset and duration of action) and safety of ketotifen fumarate 0.025% ophthalmic solution compared with vehicle placebo in pediatric subjects after single and multiple dosing. This was a double-masked, multicenter, fellow-eye, placebo-controlled, conjunctival allergen challenge trial. Eligible subjects (8-16-yr-olds) who produced a qualifying reaction to allergen were randomized to a single dose (one drop) of ketotifen fumarate in one eye and vehicle placebo in the fellow eye, followed by an allergen challenge at 15 min and 8 h post-dose. Subjects who had a qualifying reaction to allergen in the placebo-treated eye and a qualifying response to ketotifen in the active-treated eye following the single dose were re-randomized to a multiple-dose treatment period. They were instructed to instill one drop of ketotifen fumarate in one eye and placebo in the other eye twice daily for 4 wk. An allergen challenge was conducted 8 h after the last dose. The primary efficacy assessment was ocular itching, judged by the subject at 3, 7, and 10 min post-allergen challenge after single- and multiple-dose treatments. Other ocular signs and symptoms were assessed at 7, 10, and 15 min post-dose. A total of 133 subjects were randomized to single-dose treatment; 105 were evaluable for efficacy. Of these, 60 were re-randomized to multiple-dose treatment, and 55 were evaluable for efficacy. After single and multiple doses, ketotifen fumarate significantly inhibited ocular itching compared with placebo at all post-challenge timepoints (p < 0.001) and also significantly reduced hyperemia, chemosis, and lid swelling (p = 0.031). No drug-related systemic adverse events were reported, and ocular adverse events were comparable to placebo. No subject discontinued prematurely due to an adverse event. These results indicate that ketotifen fumarate 0.025% ophthalmic solution is an effective and safe treatment option for children with allergic conjunctivitis.
 ...
PMID:Efficacy and safety of single- and multiple-dose ketotifen fumarate 0.025% ophthalmic solution in a pediatric population. 1561 Mar 70


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>