Chapter 14: Muscarinic Agonists and Antagonists

Chapter 14: Muscarinic Agonists and Antagonists

 

Complete Chapter Questions With Answers

 

Sample Questions Are Posted Below

 

MULTIPLE CHOICE

 

1. A prescriber has ordered pilocarpine [Pilocar]. A nurse understands that the drug stimulates muscarinic receptors and would expect the drug to have which action?

a.	Reduction of excessive secretions in a postoperative patient
b.	Lowering of intraocular pressure in patients with glaucoma
c.	Inhibition of muscular activity in the bladder
d.	Prevention of hypertensive crisis

 

 

ANS:  B

Pilocarpine is a muscarinic agonist used mainly for topical therapy of glaucoma to reduce intraocular pressure. Pilocarpine is not indicated for the treatment of excessive secretions and mucus; in fact, pilocarpine is used to treat dry mouth. Pilocarpine does not inhibit muscular activity in the bladder. Pilocarpine is not used to prevent hypertensive crisis.

 

PTS:   1                    DIF:    Cognitive Level: Application           REF:   p. 118

TOP:   Nursing Process: Planning

MSC:  NCLEX Client Needs Category: Physiologic Integrity: Pharmacologic and Parenteral Therapies

 

2. A patient has developed muscarinic antagonist toxicity from ingestion of an unknown chemical. The nurse should prepare to administer which medication?

a.	Atropine [Sal-Tropine] IV
b.	Physostigmine [Antilirium]
c.	An acetylcholinesterase activator
d.	Pseudoephedrine [Ephedrine]

 

 

ANS:  B

Physostigmine is indicated for muscarinic antagonist toxicity. Atropine is a drying agent and would only complicate the drying action that arises from the muscarinic antagonist. An acetylcholinesterase activator would only contribute to dryness that arises from the muscarinic antagonist. Ephedrine is not indicated for muscarinic antagonist toxicity.

 

PTS:   1                    DIF:    Cognitive Level: Application           REF:   pp. 118-119 | pp. 125-126

TOP:   Nursing Process: Planning

MSC:  NCLEX Client Needs Category: Physiologic Integrity: Reduction of Risk Potential

 

3. A prescriber has ordered bethanechol [Urecholine] for a postoperative patient who has urinary retention. The nurse reviews the patient’s chart before giving the drug. Which part of the patient’s history would be a contraindication to using this drug?

a.	Asthma as a child
b.	Gastroesophageal reflux
c.	Hypertension
d.	Hypothyroidism

 

 

ANS:  A

Bethanechol is contraindicated in patients with active or latent asthma, because activation of muscarinic receptors in the lungs causes bronchoconstriction. It increases the tone and motility of the gastrointestinal (GI) tract and is not contraindicated in patients with reflux. It causes vasodilation and would actually lower blood pressure in a hypertensive patient. It causes dysrhythmias in hyperthyroid patients.

 

PTS:   1                    DIF:    Cognitive Level: Application           REF:   pp. 116-117

TOP:   Nursing Process: Assessment

MSC:  NCLEX Client Needs Category: Physiologic Integrity: Reduction of Risk Potential

 

4. A patient will begin using a transdermal preparation of a muscarinic antagonist for overactive bladder (OAB). The nurse teaches the patient what to do if side effects occur. Which statement by the patient indicates the need for further teaching?

a.	“I can use sugar-free gum for dry mouth.”
b.	“I may need laxatives for constipation.”
c.	“I should keep the site covered to prevent other people from getting the medicine.”
d.	“I will take Benadryl for any itching caused by a local reaction to the patch.”

 

 

ANS:  D

Benadryl is an antihistamine, and even though it is not classified as a muscarinic antagonist, it has anticholinergic effects. Giving it with a muscarinic antagonist greatly enhances these effects, so it should not be used. Muscarinic antagonists cause dry mouth, and patients should be taught to use sugar-free gum or candies to help with this. Muscarinic antagonists can cause constipation, and laxatives may be used. Medication applied topically can be transferred to others who come in contact with the skin, so the site should be covered.

 

PTS:   1                    DIF:    Cognitive Level: Application           REF:   p. 123

TOP:   Nursing Process: Implementation

MSC:  NCLEX Client Needs Category: Physiologic Integrity: Reduction of Risk Potential