Deck 70: Antihistamines

Question 1

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 and that the heart rate is 110 beats per minute. The nurse will expect to:

A) administer atropine to reverse the adverse effects.
B) give diazepam to prevent seizures.
C) give activated charcoal to absorb the drug.
D) prepare to provide mechanical ventilation.

Answer 1

give activated charcoal to absorb the drug.

Question 2

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 are contraindicated during the third trimester of pregnancy.
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 2

Antihistamines are contraindicated during the third trimester of pregnancy.

Question 3

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.

Answer 3

Question the order.

Question 4

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 H₁ receptors to prevent actions of histamine at these sites."
B) "Antihistamines block release of histamine from mast cells and basophils."
C) "H₁ antagonists can bind to H₁ receptors, H₂ receptors, and muscarinic receptors."
D) "First-generation antihistamines are more selective than second-generation antihistamines."

Question 5

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 6

A patient has seasonal allergies and needs an antihistamine to control symptoms. The patient likes to have wine with dinner several times a week 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 7

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 8

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) Cathartics
C) Diazepam
D) Phenytoin
E) Second-generation H1 antagonists

Question 9

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 10

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 relief from some cold symptoms by:

A) blocking H₁ receptors in nasal passages.
B) blocking muscarinic receptors in the nose.
C) reducing secretions at H₂ receptor sites.
D) having sedative effects, which help patients rest and sleep.

Question 11

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

Question 12

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 13

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)

Question 14

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."