| 单词 | antihistamine | |||
| 释义 | antihistaminean·ti·his·ta·mineA0340900 (ăn′tē-hĭs′tə-mēn′, -mĭn, ăn′tī-)antihistamine(ˌæntɪˈhɪstəˌmiːn; -mɪn)an•ti•his•ta•mine(ˌæn tiˈhɪs təˌmin, -mɪn, ˌæn taɪ-)n. an·ti·his·ta·mine(ăn′tē-hĭs′tə-mēn′)
antihistamine→ 抗组胺剂zhCNantihistamineantihistamine(ăn'tĭhĭs`təmēn), any one of a group of compounds having various chemical structures and characterized by the ability to antagonize the effects of histaminehistamine, organic compound derived in the body from the amino acid histidine by the removal of a carboxyl group (COOH). Although found in many plant and animal tissues, histamine is specifically important in human physiology because it is one of the chemicals released from ..... Click the link for more information. . Their principal use in medicine is in the control of allergies such as hay fever and hives. Some antihistamines are also useful as sedatives and for the prevention of motion sickness; others, such as fexofenadine (Allegra) and loratadine (Claritin) are nonsedating. AntihistamineA type of drug that inhibits the combination of histamine with histamine receptors. These drugs are termed either H-1 or H-2 receptor antagonists depending on which type of histamine receptor is involved. H-1 receptor antagonists are used largely for treating allergies, and H-2 receptor antagonists are used to treat peptic ulcer disease and related conditions. See Histamine The primary therapeutic use of H-1 receptor antagonists is to antagonize the effects of histamine released from cells by antigen-antibody reactions; they can thus inhibit histamine-induced effects, such as bronchoconstriction, skin reactions, for example, wheals and itching, and nasal inflammation. These drugs, therefore, are quite effective in reducing allergy signs and symptoms, especially if they are administered before contact with the relevant antigen; however they are not effective in treating asthma. Their effects vary widely, both among the drugs and from individual to individual; in young children excitement may be seen. Another common set of effects caused by many of these drugs, including dry mouth, blurred vision, and urinary retention, can be ascribed to their anticholinergic actions. H-1 receptor antagonists have low toxicity. The chief adverse effect is sedation. Overdoses of H-1 receptor antagonists may be associated with excitement or depression, and although there is no pharmacologic antidote for these drugs, good supportive care should be adequate in managing cases of poisoning. See Allergy, Antigen-antibody reaction H-2 receptor antagonists are much newer. Histamine stimulates gastric acid secretion by combining with H-2 receptors. By preventing this combination, H-2 antagonists can reduce acid secretion in the stomach, an effect that makes these drugs useful in managing various conditions, such as peptic ulcer disease. Other conditions in which H-2 antagonists are used to lower gastric acidity include reflux esophagitis, stress ulcers, and hypersecretory states such as the Zollinger-Ellison syndrome, in which tumor cells secrete large amounts of the hormone gastrin, which stimulates gastric acid secretion. In these conditions, administration of H-2 antagonists reduces symptoms and promotes healing. The toxicity of H-2 antagonists is quite low, and adverse effects are reported by only 1-2% of patients. The most common side effects are gastrointestinal upsets, including nausea, vomiting, and diarrhea. antihistamine[‚an·tē′hist·ə‚mēn]antihistamineantihistamineantihistamine[an″te-, an″ti-his´tah-mēn]Antihistamines are used to relieve the symptoms of allergic reactions, especially hay fever and other allergic disorders of the nasal passages. Some antihistamines have an antinauseant action that is useful in the relief of motion sickness. Others have a sedative and hypnotic action and may be used as tranquilizers. Many are ingredients of compound preparations used to treat coughs or the common cold. Patients for whom an antihistamine has been prescribed should be instructed about the side effects of these drugs, including drowsiness, dizziness, and muscular weakness. These side effects present a special hazard in driving an automobile or operating heavy machinery. Other side effects include dryness of the mouth and throat and insomnia. antihistamine(ăn′tē-hĭs′tə-mēn′, -mĭn, ăn′tī-)antihistamineAn agent that counteracts the effects of histamine released during allergic reactions by blocking histamine (H1) receptors.Adverse effects Dry mouth, drowsiness, urine retention in men, tachycardia. antihistamineAntihistaminic Pharmacology An agent that counteracts the effects of histamine released during allergic reactions by blocking histamine–H1 receptors Adverse effects Dry mouth, drowsiness, urine retention in ♂, tachycardia. See Histamine receptor.antihistamineOne of a group of drugs which act against histamine-a powerful and highly irritant agent released in the body by MAST CELLS, after contact with certain ALLERGENS. Antihistamine drugs fall into two groups-those that block H1 receptors and act mainly on blood vessels, and those that block H2 receptors and act mainly on the secretion of acid in the stomach. H1 receptor blockers include diphenhydramine, chlorpheniramine (chlorphenamine) (Piriton), terfenadine (Triludan), promethazine (Phenergan), cyproheptadine (Periactin), mequitazine (Primalan) and phenindamine (Thephorin). H2 receptor blockers are not usually referred to as antihistamines, although this is what they are. They include CIMETIDINE (Tagamet), and RANITIDINE (Zantac).antihistaminesee ALLERGY.Antihistamineantihistamineantihistamine
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antihistamine - a medicine used to treat allergies and hypersensitive reactions and colds; works by counteracting the effects of histamine on a receptor site