A Patient Who Has Chronic Allergies Takes Loratadine [Claritin] and Develops

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."