A 5-year-old child is brought to the emergency department after ...

[faduma]

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.

Question 2

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.

[frre432]

Answer to Question 1

ANS: C
In acute toxicity, patients present with agitation, a flushed face, tachycardia, and uncoordinated movements. There is no specific antidote, so drug removal is the focus of treatment, starting with activated charcoal to absorb the drug, followed by a cathartic to enhance excretion. Atropine would cause an increase in the heart rate. Diazepam is a central nervous system (CNS) depressant and is contraindicated, because diphenhydramine is also a CNS depressant. Mechanical ventilation is not indicated with this presentation of symptoms, although cardiovascular collapse may eventually develop.

Answer to Question 2

ANS: B
Histamine does not mediate cold symptoms, so antihistamines do not provide relief through H1 blockade. Their anticholinergic effects at muscarinic receptor sites can moderately reduce rhinorrhea, so some patients may experience some relief of this symptom. H1-receptor sites do not play a role in cold symptoms. H2-receptor sites do not play a role in cold symptoms. Sedative side effects do not alleviate cold symptoms.

[faduma]

TYSM

[matt95]

Excellent