Class
Description
Onset and Duration
Indications
Contraindications
Adverse Reactions
Drug Interactions
How Supplied
Dosage and Administration
Special Considerations
Antihistamine
Antihistamines prevent the physiological actions of histamine by preventing histamines from reaching H1- and H2-receptor sites. Antihistamines provide short-lived benefits and provide only symptomatic relief. Antihistamine is specific for conditions in which histamine excess is present (for examle, acute urticaria) but is adjunctive therapy in the treatment of anaphylactic shock because epinephrine is more effenctive. Antihistamines are quite specific for reversing extrapyramidal reactions and are probably efficacious as drying agents in upper respiratory and sinus conditions.
Symptomatic relief of allergies
Allergic reactions
Anaphylaxis
Acute dystonic reactions
Lower respiratory diseases such as astma attacks
Patients taking MAOIs
Hypersensitivity
Narrow-angle glaucome
Dose-related drowsiness
Sedation
Disrubted coordination
Hypotension
Palpitations
Tachycardia, bardycardia
Thickening of bronchial secretions
Dry mouth and throat
CNS depressants may increase depressant effects.
MAOIs may prolong and intensify anticholinergic effects of antihistamines.
Pregnancy safety: Catagory B.