Sketchy Pharm: Diphenhydramines Flashcards
Most of the body’s histamine is stored in __________.
mast cells and basophils
What kind of receptors are H1 and H2?
H1: G(q) – think of Lisander with the Q-shaped dandelion (he’s about to get allergies, and that is H1)
H2: G(s) –think of the stomach with the two S-shaped handles
H2 receptors, when stimulated, induce ______________.
gastric acid secretion
H1 receptors, when stimulated from mast-cell histamine, induce _______________.
nasal and bronchial mucus secretion; bronchoconstriction on smooth muscle; and vasodilation with increased vascular permeability
H1-blocking agents enter the _____________ to alleviate seasickness.
vestibular system
__________-generation antihistamines easily enter the CNS.
First (where they bind H1)
True or false: first-generation antihistamines block muscarinic channels in the CNS and PNS.
True (this is why they lead to some of the same side effects); they can thus also be used to treat motion sickness and the extrapyramidal effects of Parkinson’s by reestablishing the dopamine-choline balance
Antihistamines can also lead to increased ____________ and _________ antagonism.
appetite (with weight gain); serotonin and alpha-1
What are the three main 2nd-generation antihistamines?
Fexofenadine, cetirizine, and loratidine
What are the first-generation antihistamines?
Diphenhydramine Chlorpheniramine Promethazine Hydroxyzine Meclizine