7Important definitions What is histamine? Endogenous chemical stored in mast cells involved in normal regulation of physiologic functionsWhat is an allergen? An ordinarily harmless substance that the body recognizes as foreignThe result? The body produces antibodies (IgE) to fight the “foreign substance” causes the release of histamineEffects of histamine - redness, itching, watery eyes, vasodilation
8AntihistaminesAction - blocks H1 receptor sites by attaching to mast cells in nasal passagesEffects - prevents a histamine responsedries membranesshrinks swollen tissuesdecreases rednessdecreases itching
10Antihistamines Examples (Diphenhydramine) - Benadryl, Tylenol PM (Doxylamine Succinate) - Unisom(Clemastine) - Tavist(Promethazine HCl) - PhenerganClaritinAllegraZyrtec** many antihistamines also contain a decongest.
11Antitussives - (Cough Suppressant) Suppress a non-productive coughTypes & Effectsnarcotic - suppress cough reflexnon-narcotic - inhibit irritating effects of histamine, decrease sensitivity to stimuliAdverse effect – sedation, interactions w/other medsExamples(Dextromethorphan)(Codeine)
12Cough Expectorant Recommended for productive coughs Facilitate production and ejection of mucusDecrease viscosityExamplesGuaifenesinExplain the logic of combining an expectorant with a suppressant?????
13Fixed-Ratio Combination Products 1. Some active ingredients not needed2. Not possible to formulate dosage to person3. Ingredients are sometimes less than therapeutic doses4. Risk of interaction5. Cost
14Zinc Inhibit the production of viruses Recently used to decrease symptoms of the common cold