Author Question: A patient is preparing for travel and reports having frequent motion sickness. The nurse will tell ... (Read 59 times)

genevieve1028 · **on:** Jul 23, 2018

A patient is preparing for travel and reports having frequent motion sickness. The nurse will tell the patient to ask the provider about which antihistamine?

a. Desloratadine (Clarinex)
b. Diphenhydramine (Phenadoz)
c. Hydroxyzine (Vistaril)
d. Promethazine (Phenergan)

Question 2

A patient who has chronic allergies takes loratadine (Claritin) and develops a severe reaction to bee stings. The patient asks the nurse why the antihistamine did not prevent the reaction. What will the nurse say?

a. Allergy symptoms that are severe are caused by mediators other than histamine.
b. H1 blockers do not prevent the release of histamine from mast cells and basophils.
c. Second-generation H1 blockers contain less active drug and do not work in severe reactions.
d. Severe allergic reactions occur through actions on muscarinic receptors.

macagnavarro · **Reply #1 on:** Jul 23, 2018

Answer to Question 1

ANS: D
Some antihistamines, including promethazine, are labeled for use in motion sickness. Desloratadine, diphenhydramine, and hydroxyzine are not used for motion sickness.

Answer to Question 2

ANS: A
Severe allergic reactions with symptoms of anaphylaxis are caused by mediators other than histamine, so the benefits of antihistamines are limited. H1 blockers do not block the release of histamine, but this is not why they are not effective in anaphylaxis. Second-generation agents are as effective as first-generation agents in allergic reactions mediated by histamine; neither is effective for treating anaphylaxis.