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 hista-mine."
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."
A
Severe allergic reactions with symptoms of anaphylaxis are caused by mediators other than his-tamine, so the benefits of antihistamines are limited. H1 blockers do not block the release of his-tamine, 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.
You might also like to view...
Monitoring for a patient being prescribed iron for iron deficiency anemia includes:
1. Reticulocyte count 1 week after therapy is started 2. Complete blood count every 2 weeks throughout therapy 3. Hemoglobin level at 1 week of therapy 4. INR weekly throughout therapy
Age is a factor in different responses to pain. Which of the following age-related statements about pain is NOT true?
1. Preterm and newborn infants do not yet have functional pain pathways. 2. Painful experiences and prolonged exposure to analgesic drugs during pregnancy may permanently alter neuronal organization in the child. 3. Increases in the pain threshold in older adults may be related to peripheral neuropathies and changes in skin thickness. 4. Decreases in pain tolerance are evident in older adults.
A nurse is changing the dressing and accidentally drops the packing onto the client's abdomen. The client has a large, deep abdominal incision that is packed with sterile half-inch packing and covered with a dry 4 ? 4 gauze. The nurse should:
1. Add alcohol to the packing and insert it into the incision 2. Throw the packing away, and prepare a new one 3. Pick up the packing with sterile forceps, and gently place it into the incision 4. Rinse the packing with sterile water, and put the packing into the incision with sterile gloves
African Americans have a(n)
A. relatively fast rate of nicotine metabolism B. relatively slow rate of nicotine metabolism C. rate of nicotine metabolism equal to whites D. immunity to drug dependence