Deck 70: Antihistamines

Question 1

A pregnant patient asks the nurse if she can take antihistamines for seasonal allergies during her pregnancy. What will the nurse tell the patient?

A) Antihistamines should be avoided unless absolutely necessary.
B) Second-generation antihistamines are safer than first-generation antihistamines.
C) Antihistamines should not be taken during pregnancy but may be taken when breast-feeding.
D) The margin of safety for antihistamines is clearly understood for pregnant patients.

Answer 1

Antihistamines should be avoided unless absolutely necessary.

Question 2

A 5-year-old child with seasonal allergies has been taking 2.5 mL of cetirizine [Zyrtec] syrup once daily. The parents tell the nurse that the child does not like the syrup,and they do not think that the drug is effective. The nurse will suggest they discuss which drug with their child's healthcare provider?

A) Cetirizine [Zyrtec] 5-mg chewable tablet once daily
B) Loratadine [Claritin] 10-mg chewable tablet once daily
C) Fexofenadine [Allegra] syrup 5 mL twice daily
D) Desloratadine [Clarinex] 5-mg rapid-disintegrating tablet once daily

Answer 2

Cetirizine [Zyrtec] 5-mg chewable tablet once daily

Question 3

Which parenteral antihistamines have sedative effects that are classified as low to none? (Select all that apply.)

A) Cetirizine [Zyrtec]
B) Clemastine [Tavist Allergy]
C) Desloratadine [Clarinex]
D) Fexofenadine [Allegra]
E) Loratadine [Claritin]

Answer 3

Desloratadine [Clarinex]
Fexofenadine [Allegra]
Loratadine [Claritin]

Question 4

A patient has seasonal allergies and needs an antihistamine to control symptoms. The patient likes to have wine with dinner occasionally and wants to know which antihistamine will be the safest to take. The nurse will tell the patient to discuss which medication with the provider?

A) Cetirizine [Zyrtec]
B) Fexofenadine [Allegra]
C) Levocetirizine [Xyzal]
D) Loratadine [Claritin]

Question 5

A patient is brought to the emergency department after ingesting a handful of diphenhydramine [Benadryl] tablets. The patient has dilated pupils,a flushed face,and tremors. The patient is agitated and has a heart rate of 110 beats per minute. The nurse may anticipate administering which agents? (Select all that apply.)

A) Activated charcoal
B) Atropine
C) Cathartics
D) Lorazepam
E) Second-generation H₁ antagonists

Question 6

A patient will begin taking fexofenadine [Allegra] for hay fever. The nurse teaching this patient will tell the patient that:

A) fexofenadine should be taken with food to prevent gastrointestinal (GI) symptoms.
B) the medication may be taken once or twice daily.
C) tolerance to sedation will occur in a few weeks.
D) with renal impairment, this drug should be taken every other day.

Question 7

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) "H₂ blockers do not prevent the release of histamine from mast cells and basophils."
C) "Second-generation H₂ blockers contain less active drug and do not work in severe reactions."
D) "Severe allergic reactions occur through actions on muscarinic receptors."

Question 8

A prescriber orders hydroxyzine [Vistaril] for a patient with acute urticaria. The nurse will include which information when teaching the patient about this drug?

A) The drug will reduce redness and itching but not edema.
B) This antihistamine is not likely to cause sedation.
C) The patient should avoid drinking alcohol while taking the drug.
D) The patient should report shortness of breath while taking the drug.

Question 9

A patient tells a nurse that antihistamines help relieve cold symptoms and wants to know why they are not recommended or prescribed for this purpose. The nurse tells the patient that antihistamines provide only mild relief from some cold symptoms by:

A) anticholinergic properties that decrease rhinorrhea.
B) blocking H₂ receptors in nasal passages.
C) reducing secretions at H₂ receptor sites.
D) having sedative effects, which help patients rest and sleep.

Question 10

A family is preparing for travel and the parents report that their 5-year-old child has frequent motion sickness. The nurse will tell the parents to ask the provider about which antihistamine to help prevent symptoms?

A) Desloratadine [Clarinex]
B) Dimenhydrinate [Dramamine]
C) Hydroxyzine [Vistaril]
D) Promethazine [Phenergan]

Question 11

A 5-year-old child is brought to the emergency department after ingesting diphenhydramine [Benadryl]. The child is uncoordinated and agitated. The nurse observes that the child's face is flushed,the temperature is 37.1°C,and the heart rate is 110 beats per minute. The nurse will expect to:

A) administer atropine to reverse the adverse effects.
B) apply ice packs to stop the flushing.
C) give activated charcoal to absorb the drug.
D) prepare to provide mechanical ventilation.

Question 12

A nurse is teaching a group of nursing students about antihistamines. Which statement by a student indicates an understanding of the mechanism of action of the antihistamines?

A) "Antihistamines block H₂ receptors to prevent actions of histamine at these sites."
B) "Antihistamines block release of histamine from mast cells and basophils."
C) "H₂ antagonists can bind to H₂receptors, H₂ receptors, and muscarinic receptors."
D) "First-generation antihistamines are more selective than second-generation antihistamines."

Question 13

A provider has ordered intravenous promethazine [Phenergan] for an adult patient postoperatively to prevent nausea and vomiting (N/V). What will the nurse do?

A) Administer the drug at a rate of 25 mg/min or more to achieve maximum effects.
B) Contact the provider to suggest using dimenhydrinate [Dramamine] instead.
C) Ensure that the IV is infusing freely through a large-bore needle.
D) Monitor the patient closely for cardiac dysrhythmias.

Question 14

An 18-month-old child develops an urticarial reaction after a transfusion. The prescriber orders intravenous promethazine [Phenergan]. What will the nurse do?

A) Give the medication as ordered.
B) Monitor the child for bronchoconstriction.
C) Question the order.
D) Request an order to give the drug orally.