2021 Exam 3 Drug List.docx 100% CRRT Chapter 39: Drugs for Allergic Rhinitis and the Common Cold

Traditional Antihistamines • Work both peripherally and centrally • Have anticholinergic effects o Dry mouth o Constipation o Blurred vision o Urinary hesitant (be careful with BPH) o Tachycardia • Drugs: o Diphenhydramine (Benadryl) ▪ Also used for Parkinson’s and insomnia o Brompheniramine (Dimetapp) o Chlorpheniramine (Chlor-Trimeton) o Dimenhydrinate (Dramamine) ▪ Also used for motion sickness o Meclizine (Antivert) ▪ Also used for vertigo o Promethazine (Phenergan) Non-sedating/Peripherally Acting Antihistamines • Second generation of antihistamines with less anticholinergic effects and less sedative effects • Developed to eliminate unwanted adverse effects mainly sedation • Works peripherally to block the actions of histamine • Drugs: o Fexofenadine (Allegra) o Loratadine (Claritin) o Cetirizine (Zyrtec) Histamine versus Antihistamine Effects • Histamine effects: stimulate salivary, gastric, lacrimal and bronchial secretions o Mast cells release histamine and other substances, resulting in allergic reactions • Antihistamine effects: reduce salivary, gastric, lacrimal, and bronchial secretions. o Binds to histamine receptors, thus preventing histamine from causing a response What are the antihistamine effects on the body? • Skin: o Reduce capillary permeability, wheal-and-flare formation, itching • Anticholinergic: o Drying effect that reduces nasal, salivary, and lacrimal gland secretions (runny nose, tearing, and itching eyes) • Sedative: o Some antihistamines cause drowsiness What are the antihistamines adverse effects? • All the anticholinergic (drying) effects: o Dry mouth o Tachycardia o Difficulty urinating o Constipation o Changes in vision Nursing Implications: Antihistamines • Contraindicated in the presence of acute asthma attacks and lower respiratory diseases, such as pneumonia o Must relieve the asthma attack first, then you