Cholinergic System

Anticholinergic

Blocks the action of acetylcholine

Anticholinesterase (acetycholinesterase inhibitor)

Blocks the breakdown of acetylcholine

Cholinesterase

Causes the breakdown of acetylcholine

Cholenergic antagonist

Drugs that inhibit the actions of acetylcholine by occupying the acetylcholine receptors The major body tissues and organs affected by this drug are the heart, respiratory tract, GI tract, urinary bladder, eyes, and exocrine glands. Anticholinergics and adrenergic agonists produce many of the same responses. decrease in GI motility, a decrease in salivation, dilation of pupils—also called mydriasis—and an increase in pulse rate.

Cholinergic agonists (muscarinic agonists or parasympathomimetic)

Drugs that stimulate the parasympathetic nervous system decreases the heart rate mimic the parasympathetic neurotransmitter acetylcholine. nonselective because they can affect both the muscarinic and the nicotinic receptors.

Nicotinic receptor

Impacts skeletal muscles

Direct-acting parasympathomimetic

Mimics cholinergic actions

Cholinergic agonists

Stimulate the parasympathetic system

Acetylcholine (ACh)

Stimulates muscarinic and nicotinic receptors

Muscarinic receptor

Stimulates smooth muscle and slows heart rate

Bethanechol (Urecholine)

a direct-acting cholinergic agonist acts on the muscarinic (cholinergic) receptor and is used primarily to increase urination in the treatment of urinary retention and neurogenic bladder. Contraindication: procainamide, mecamylamine

The nurse is taking care of five clients in the emergency department. Which client(s) would be candidate(s) to receive atropine? (Select all that apply.) a. A client having surgery for appendicitis b. A client with a heart rate of 38 beats/minute and dizziness c. A client with paralytic ileus d. A client with urinary retention e. A client with gastric ulcers

a. A client having surgery for appendicitis b. A client with a heart rate of 38 beats/minute and dizziness

The pediatric client has urinary retention. Which cholinergic drug does the nurse anticipate will be prescribed to increase urination? a. Bethanechol b. Edrophonium chloride c. Metoclopramide d. Neostigmine bromide

a. Bethanechol

Anticholinergic drugs are contraindicated in clients with which disease processes? (Select all that apply.) \ a. Coronary artery disease b. Diabetes mellitus c. Gastrointestinal obstruction d. Supraventricular tachycardia

a. Coronary artery disease c. Gastrointestinal obstruction d. Supraventricular tachycardia

Which outcome to the body would occur from receiving large doses of cholinergic drugs? (Select all that apply.) a. Decreased blood pressure b. Decreased salivation c. Increased bronchial secretions d. Mydriasis e. Urinary retention

a. Decreased blood pressure, c. Increased bronchial secretions

Which teaching point(s) will the nurse include for a client taking hyoscyamine for irritable bowel syndrome? (Select all that apply.) a. Ensure adequate fluid intake. b. Do not drive until you are aware of how this drug will affect your vision. c. Sucking on hard candy may help with dry mouth. d. Increased sweating is a common side effect. e. Report a rapid heart rate to your health care provider.

a. Ensure adequate fluid intake. b. Do not drive until you are aware of how this drug will affect your vision. c. Sucking on hard candy may help with dry mouth. e. Report a rapid heart rate to your health care provider.

Direct acting cholinergic agonists

act on receptors to activate a tissue response

Scopolomine (Transderm Scop)

anticholinergic—or muscarinic antagonist—drug classified as an antihistamine for motion sickness available topically as a skin patch placed behind the ear. Transdermal scopolamine is delivered over 3 days and is frequently prescribed for activities such as flying, cruising on the water, and bus or automobile trips.

Which type of medication is bethanechol? a. Anticholinergic b. Cholinergic agonist c. Cholinesterase inhibitor d. Sympatholytic

b. Cholinergic agonist

Anticholinergic eyedrops are used for which purpose? a. Constrict the pupils b. Dilate the pupils c. Decrease the intraocular pressure d. Detect astigmatism

b. Dilate the pupils

The client who was prescribed bethanechol asks the nurse how it works. Which response would be most appropriate by the nurse? a. "This drug decreases bladder tone." b. "This drug inhibits bladder contraction." c. "This drug promotes contraction of the bladder." d. "This drug stimulates urine production."

c. "This drug promotes contraction of the bladder."

The client with new diagnosis of peptic ulcers was prescribed propantheline. Which substance would the nurse teach that is a priority point for nutrition? a. Calcium b. Fat c. Fiber d. Protein

c. Fiber

A client with narrow-angle glaucoma is prescribed an anticholinergic drug. Which action would be a priority by the nurse? a. Administer the medication as ordered after verifying the patient's identity. b. Give only one-half of the prescribed dose. c. Hold the dose and contact the health care provider. d. Wait until after the patient has taken glaucoma medication and then give the drug.

c. Hold the dose and contact the health care provider.

Which drug treats myasthenia gravis by increasing muscle strength? a. Bethanechol b. Edrophonium chloride c. Neostigmine bromide d. Pilocarpine

c. Neostigmine bromide

Which statement describes the mechanism of action for bethanechol? a. Inhibits muscarinic receptors b. Inhibits nicotinic receptors c. Stimulates muscarinic receptors d. Stimulates nicotinic receptors

c. Stimulates muscarinic receptors

The nurse would question an order for atropine for which client? a. A client with a peptic ulcer b. A client with parkinsonism c. A client with cirrhosis d. A client with narrow-angle glaucoma

d. A client with narrow-angle glaucoma

The client has been prescribed bethanechol and is experiencing decreased urinary output. Which action would be a priority by the nurse? a. Catheterize the client to drain the bladder and measure output. b. Encourage the client to increase fluid intake to increase urinary output. c. Encourage the client to relax when urinating. d. Notify the health care provider with current in-take and output values.

d. Notify the health care provider with current in-take and output values.

The client has been taking bethanechol and is experiencing flushing, sweating, nausea, and abdominal cramps. Which action would be best for the nurse to take? a. Document the client's manifestations. b. Give the client a laxative. c. Increase the client's fluid intake. d. Obtain an order to administer atropine

d. Obtain an order to administer atropine

A specific group of anticholinergics may be pre-scribed in the early treatment of which neuromuscular disorder? a. Multiple sclerosis b. Muscular dystrophy c. Myasthenia gravis d. Parkinsonism

d. Parkinsonism

Which drug would the nurse anticipate administering to a client who ingested an organophosphate poison? a. Bethanechol b. Edrophonium chloride c. Metoclopramide d. Pralidoxime chloride

d. Pralidoxime chloride

Indirect-Acting Cholinergic Agonists

inhibit the action of the enzyme cholinesterase (ChE), also called acetylcholinesterase (AChE) cholinesterase (ChE) inhibitors, acetylcholinesterase (AChE) inhibitors, or anticholinesterases permits skeletal muscle stimulation, which increases the force of muscular contraction.

Side effects of antihistamines

xerostomia, drowsiness, visual disturbances (especially blurred vision resulting from pupillary dilation), constipation secondary to decreased GI peristalsis, urinary retention related to decreased bladder tone, tachycardia (when taken in large doses), hypotension, dysphagia, anhidrosis, and flushing.