Chapter 19 Cholinergic Agonists and Anticholinergics
direct-acting cholinergic: Eye
Pilocarpine- constricts pupils (miosis) opening canal of Schlemm to promote drainage of aqueous humor (fluid) *treatment of glaucoma
the nurse is taking care of 5 patients in the ER. which patient would be candidates to receive atropine? (select all that apply) a. 25 yr old having surgery for appendicitis b. 42 yr old with HR of 38 beats/min and dizziness c. 50 yr old with diarrhea d. 61 yr old with urinary retention e. 68 yr old with gastric ulcers
a. 25 yr old having surgery for appendicitis b.42 yr old with HR of 38 beats/min and dizziness *preop med to help control oral secretions. used for symptomatic patients with HR fewer than 50 beats/min
anticholinergic drugs are contraindicated in patients with which disease processes? (Select all that apply) a. CAD d. DM c. GI obstruction d. supraventricular tachycardia
a. CAD c. GI obstruction D. supraventricular tachycardia
what teaching points will the nurse include for a 30 yr old patient who is taking hyoscyamine (Cystopaz) for irritable bowel syndrome? (select all that apply) a. ensure adequate fluid intake b. don't drive until you are aware of how this medication will affect your vision c sucking on hard candy may help with dry mouth d. increased sweating is a common s/e e. report rapid HR to your HCP
a. ensure adequate fluid intake b. don't drive until you are aware of how this medication will affect your vision c sucking on hard candy may help with dry mouth e. report rapid HR to your HCP
the nurse realizes that cholinergic agonists mimi which parasympathetic neurotransmitter? a. dopamine b. acetylcholine c. cholinesterase d. monoamine oxidase
b. acetylcholine
which type of medication is bethanecol (Urecholine)? a. anticholinergic b. cholinergic agonist c. cholinesterase inhibitor d. sympatholytic
b. cholinergic agonist
the older adult patient is taking benztropine (Cogentin) for symptoms associated with parkinsonism. the nurse will instruct the patient to report which clinical manifestations to the HCP? (select all that apply) a. diarrhea b. dizziness c. hallucinations d. hyperthermia e. palpitations
b. dizziness c. hallucinations d. hyperthermia e. palpitations
the nurse teaches the patient receiving atropine (Atreza) to expect which side effect? a. diarrhea b. bradycardia c. blurred vision d. frequent urination
c. blurred vision
the patient is admitted for evaluation of peptic ulcers. she is taking propantheline (Pro-Xanthine) 3x per day. the nurse is teaching this patient about nutrition while taking this medication. the priority nutrition teaching point is that the patient should eat foods that are high in which component? a. Calcium b. fat c. fiber d. protein
c. fiber * due to the decrease in GI motility that can be associated with propantheline, the patient should be encourage to eat foods that are high in fiber and drink adequate amounts of liquid to prevent constipation
how does the body respond to large doses of cholinergic drugs? (Select all that apply) a. decreased BP b. decreased salivation c. increased bronchial secretions d. mydriasis e. urinary retention
c. increase bronchial salivation
which medication treats MG by increasing muscle strength? a. bethanechol (Urecholine) b. edrophonium chloride (Tensilon) c. neostigmine bromide (Prostigmin) d. Pilocarpine (Pilocar)
c. neostigmine bromide (Prostigmin)
how does bethanechol (Urecholine) work in the body? a. inhibits muscarinic receptors b. inhibits nicotinic receptors c. stimulates muscarinic receptors d. stimulates nicotinic receptors
c. stimulates muscarinic receptors
antidote cholinergic overdose
cholinergic antidote is atropine sulfate *cholinergic crisis: muscle weakness (MG)
parasympathetic nervous system (PNS)
cholinergic system rest and digest receptors: nicotinic and muscarinic neurotransmitter: acetylcholine acetylcholinesterase can inactivate the response of aCh
2 major groups that affect PNS
cholingeric agonist ( sympathomimetic) anticholinergics ( sympatholytics)
the nurse would question an order for atropine for which patient? a. 35 yr old with peptic ulcer b. 50 yr old with parkinsonism c. 55 yr old with cirrhosis d. 60 yr old with glaucoma
d. 60 yr old with glaucoma * atropine like drugs should not be admin to patients with NA glaucoma because they will increase IOP
the nurse is administering bethanechol (Urecholine), a cholinergic agonist and should know that the expected cholinergic effects include which of the following? a. increased HR b. decreased peristalsis c. decreased salivation d. increased pupil constriction
d. increased pupil constriction
Dicyclomin (Bentyl) is an anticholinergic which the nurse realizes is given to treat which condition? a. mydriasis b. constipation c. urinary retention d. irritable bowel syndrome
d. irritable bowel syndrome
the patient has been prescribed bethanechol and is experiencing decreased urinary output. what is the nurses' priority action? a. catheterize the patient to drain the bladder and measure output. b. encourage the patient to increase fluid intake to increase urianry output c. encourage the patient to relax when urinating. d. notify the HCP with current intake and output values
d. notify the HCP with current intake and output values * bethanechol is used to treat urinary retention but will not be effective and should not be used in the case of a mechinal obstruction. if this patient was prescribed bethanechol for urinary retention and the urine output is decreasing, the HCP should be notified.
the patient has been taking bethanechol and is experiencing flushing, sweating, nausea, and abdominal cramps. what is the nurse's best action? a. document the patient's manifestations b. give the patient a laxative c. increase the patient's fluid intake d. prepare to admin atropine
d. prepare to admin atropine * cholinergic agonist. the patient is experiencing an adverse response and the treatment choice is atropine.
a specific group of anticholinergics may be prescribed in the early treatment of which neuromuscular disorder? a. MS b. muscle dystrophy c. MG d. Parkinsonism
d.Parkinsonism
indirect-acting cholinergic agonists
do not act on receptors, they inhibit or inactivate the enzyme ChE, permitting ACh to accumulate at the receptor sites. *allowing ACh to activate muscarinic & nicotinic receptors. this action permits skeletal muscle stimulation, which increase the force of muscular contraction (good for MG)
PNS effects on: eyes, lungs, heart, blood vessels, gastrointestinal, bladder, uterus, salivary glands
eyes: constricts pupils (miosis) lungs: bronchoconstricts & increases secretions (sleepy) heart:decreases HR blood vessels: bronchodilates gastrointestinal: increases peristalsis bladder: constricts bladder uterus: --- salivary: increases salivation
muscarinic agonists s/e and adverse reactions
hypotension, bradycardia, blurred vision, excessive salivation, increased gastric acid secretion, abdominal cramps, diarrhea, bronchoconstriction, caution: low BP & HR. intestinal/ urinary tract obstruction, severe bradycardia, active asthma.
cholinergic agonists (sympathomimetics)
neurotransmitter: acetylcholine (ACh) receptors: muscarinic receptors: smooth M. and slow HR nicotinic receptors: neuromuscular, affect skeletal M. direct-acting cholinergic agonists- act on receptors o activate tissue response indirect-acting cholinergic agonists- inhibit the action of enzyme cholinesterase (ChE) by forming a chemical complex, thus permitting acetylcholine to persist and attach to a receptor *major responses: stimulate bladder and GI tone, constrict pupils, increase neuromuscular transmission.
direct-acting cholinergic agonists
primarily selective to muscarinic receptors ex: Bethanechol (Urecholine) metoclopramide HCl (Reglan) *bethanechol increases micturition *meoclopramide treat GERD *give cholinergic agonists 1 hour before or 2 hours after meals. * check bilirubin.
cholinesterase inhibitors
reversible: binds to enzyme ChE for several minutes to hours irreversible: binds to enzyme permanently.
Reversible Cholinesterase Inhibitors
use to: 1. produce pupillary constriction in treatment of glaucoma 2. increase muscle strength in patients with MG ex: neostigmine (Prostigmin) pyridostigmine Br (Mestinon) ambenonium Cl (Mytelase) *edrophonium Cl (Tensilon) caution: bradycardia, asthma, peptic ulcers, or hyperthyroidism
Irreversible Cholinesterase Inhibitors
used to produce pupillary constrictions