chapter 21 cholinergic-blocking drugs mosby items and derived items © 2011, 2007, 2004 by mosby,...
TRANSCRIPT
![Page 1: CHAPTER 21 Cholinergic-Blocking Drugs Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc](https://reader035.vdocuments.net/reader035/viewer/2022062221/56649dba5503460f94aaa5d8/html5/thumbnails/1.jpg)
CHAPTER 21
Cholinergic-Blocking Drugs
Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.
![Page 2: CHAPTER 21 Cholinergic-Blocking Drugs Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc](https://reader035.vdocuments.net/reader035/viewer/2022062221/56649dba5503460f94aaa5d8/html5/thumbnails/2.jpg)
2Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.
Definition
Drugs that block or inhibit the actions of acetylcholine (ACh) in the parasympathetic nervous system (PSNS)
Also known as anticholinergics
![Page 3: CHAPTER 21 Cholinergic-Blocking Drugs Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc](https://reader035.vdocuments.net/reader035/viewer/2022062221/56649dba5503460f94aaa5d8/html5/thumbnails/3.jpg)
Mechanism of Action
Competitive antagonists Compete with ACh Block ACh at muscarinic receptors
in the PSNS As a result, ACh is unable to bind to the
receptor site and cause a cholinergic effect Once these drugs bind to receptors, they
inhibit nerve transmission at these receptors
![Page 4: CHAPTER 21 Cholinergic-Blocking Drugs Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc](https://reader035.vdocuments.net/reader035/viewer/2022062221/56649dba5503460f94aaa5d8/html5/thumbnails/4.jpg)
![Page 5: CHAPTER 21 Cholinergic-Blocking Drugs Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc](https://reader035.vdocuments.net/reader035/viewer/2022062221/56649dba5503460f94aaa5d8/html5/thumbnails/5.jpg)
Chemical Class
Natural Synthetic/Semisynthetic
atropine benztropine clidinium
belladonna dicyclomine glycopyrrolate
hyoscyamine homatropine ipratropium
scopolamine isopropamide methscopolamine
oxybutynin propantheline
tolterodine trihexyphenidyl
Many Others
![Page 6: CHAPTER 21 Cholinergic-Blocking Drugs Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc](https://reader035.vdocuments.net/reader035/viewer/2022062221/56649dba5503460f94aaa5d8/html5/thumbnails/6.jpg)
Drug Effects
Cardiovascular Small doses: decrease heart rate Large doses: increase heart rate
CNS Small doses: decrease muscle rigidity
and tremors Large doses: drowsiness, disorientation,
hallucinations
![Page 7: CHAPTER 21 Cholinergic-Blocking Drugs Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc](https://reader035.vdocuments.net/reader035/viewer/2022062221/56649dba5503460f94aaa5d8/html5/thumbnails/7.jpg)
Drug Effects (cont’d)
Eye Dilated pupils (mydriasis) Decreased accommodation caused by paralysis
of ciliary muscles (cycloplegia) Gastrointestinal
Relax smooth muscle tone of GI tract Decrease intestinal and gastric secretions Decrease motility and peristalsis
![Page 8: CHAPTER 21 Cholinergic-Blocking Drugs Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc](https://reader035.vdocuments.net/reader035/viewer/2022062221/56649dba5503460f94aaa5d8/html5/thumbnails/8.jpg)
Drug Effects (cont’d)
Genitourinary Relaxed detrusor muscle Increased constriction of internal sphincter Result: urinary retention
Glandular Decreased bronchial secretions, salivation,
sweating
![Page 9: CHAPTER 21 Cholinergic-Blocking Drugs Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc](https://reader035.vdocuments.net/reader035/viewer/2022062221/56649dba5503460f94aaa5d8/html5/thumbnails/9.jpg)
Drug Effects (cont’d)
Respiratory Decreased bronchial secretions Dilated bronchial airways
![Page 10: CHAPTER 21 Cholinergic-Blocking Drugs Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc](https://reader035.vdocuments.net/reader035/viewer/2022062221/56649dba5503460f94aaa5d8/html5/thumbnails/10.jpg)
Indications: CNS
Decreased muscle rigidity and muscle tremors Parkinson’s disease Drug-induced extrapyramidal reactions
![Page 11: CHAPTER 21 Cholinergic-Blocking Drugs Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc](https://reader035.vdocuments.net/reader035/viewer/2022062221/56649dba5503460f94aaa5d8/html5/thumbnails/11.jpg)
Indications: Cardiovascular
Affect the heart’s conduction system Low doses: slow the heart rate High doses: block inhibitory vagal effects on SA
and AV node pacemaker cells• Results in increased heart rate
![Page 12: CHAPTER 21 Cholinergic-Blocking Drugs Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc](https://reader035.vdocuments.net/reader035/viewer/2022062221/56649dba5503460f94aaa5d8/html5/thumbnails/12.jpg)
Indications: Cardiovascular (cont’d)
Atropine Used primarily for cardiovascular disorders
• Diagnosis of sinus node dysfunction• Symptomatic second-degree heart block• Severe sinus bradycardia with hemodynamic
compromise (advanced life support)
![Page 13: CHAPTER 21 Cholinergic-Blocking Drugs Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc](https://reader035.vdocuments.net/reader035/viewer/2022062221/56649dba5503460f94aaa5d8/html5/thumbnails/13.jpg)
Indications: Respiratory
Blocking the cholinergic stimulation of the PSNS allows unopposed action of the SNS
Results Decreased secretions from nose, mouth,
pharynx, bronchi Relaxed smooth muscles in bronchi
and bronchioles Decreased airway resistance Bronchodilation
![Page 14: CHAPTER 21 Cholinergic-Blocking Drugs Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc](https://reader035.vdocuments.net/reader035/viewer/2022062221/56649dba5503460f94aaa5d8/html5/thumbnails/14.jpg)
Indications: Respiratory (cont’d)
Respiratory drugs are used to treat: Exercise-induced bronchospasms Chronic bronchitis Asthma Chronic obstructive pulmonary disease
![Page 15: CHAPTER 21 Cholinergic-Blocking Drugs Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc](https://reader035.vdocuments.net/reader035/viewer/2022062221/56649dba5503460f94aaa5d8/html5/thumbnails/15.jpg)
Indications: Gastrointestinal
PSNS controls gastric secretions and smooth muscles that produce gastric motility
Blockade of PSNS results in: Decreased secretions Relaxation of smooth muscle Decreased GI motility and peristalsis
![Page 16: CHAPTER 21 Cholinergic-Blocking Drugs Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc](https://reader035.vdocuments.net/reader035/viewer/2022062221/56649dba5503460f94aaa5d8/html5/thumbnails/16.jpg)
Indications: Gastrointestinal (cont’d)
Gastrointestinal drugs are used to treat: Irritable bowel disease GI hypersecretory states
![Page 17: CHAPTER 21 Cholinergic-Blocking Drugs Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc](https://reader035.vdocuments.net/reader035/viewer/2022062221/56649dba5503460f94aaa5d8/html5/thumbnails/17.jpg)
Indications: Genitourinary
Reflex neurogenic bladder Incontinence
![Page 18: CHAPTER 21 Cholinergic-Blocking Drugs Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc](https://reader035.vdocuments.net/reader035/viewer/2022062221/56649dba5503460f94aaa5d8/html5/thumbnails/18.jpg)
Indications
Acute pancreatitis: reduces gastric and pancreatic secretions
Preoperatively: reduces salivary secretions
![Page 19: CHAPTER 21 Cholinergic-Blocking Drugs Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc](https://reader035.vdocuments.net/reader035/viewer/2022062221/56649dba5503460f94aaa5d8/html5/thumbnails/19.jpg)
Adverse Effects
Body System Adverse Effects
Cardiovascular Increased heart rate, dysrhythmias
CNS CNS excitation, restlessness, irritability, disorientation,
hallucinations, delirium
![Page 20: CHAPTER 21 Cholinergic-Blocking Drugs Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc](https://reader035.vdocuments.net/reader035/viewer/2022062221/56649dba5503460f94aaa5d8/html5/thumbnails/20.jpg)
Adverse Effects (cont’d)
Body System Adverse Effects
Eye Dilated pupils, decreased visual accommodation, increased intraocular
pressure
Gastrointestinal Decreased salivation, decreased gastric secretions,
decreased motility
![Page 21: CHAPTER 21 Cholinergic-Blocking Drugs Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc](https://reader035.vdocuments.net/reader035/viewer/2022062221/56649dba5503460f94aaa5d8/html5/thumbnails/21.jpg)
Adverse Effects (cont’d)
Body System Adverse Effects
Genitourinary Urinary retention
Glandular Decreased sweating
Respiratory Decreased bronchial secretions
![Page 22: CHAPTER 21 Cholinergic-Blocking Drugs Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc](https://reader035.vdocuments.net/reader035/viewer/2022062221/56649dba5503460f94aaa5d8/html5/thumbnails/22.jpg)
Interactions
Antihistamines, phenothiazines, tricyclic antidepressants, MAOIs
When given with cholinergic blocking drugs, cause additive cholinergic effects, resulting in increased effects
![Page 23: CHAPTER 21 Cholinergic-Blocking Drugs Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc](https://reader035.vdocuments.net/reader035/viewer/2022062221/56649dba5503460f94aaa5d8/html5/thumbnails/23.jpg)
Nursing Implications
Keep in mind that these drugs block the action of ACh in the PSNS
Assess for allergies, presence of BPH, glaucoma, tachycardia, MI, HF, hiatal hernia, and GI or GU obstruction
Perform baseline assessment of vital signs and systems overview
![Page 24: CHAPTER 21 Cholinergic-Blocking Drugs Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc](https://reader035.vdocuments.net/reader035/viewer/2022062221/56649dba5503460f94aaa5d8/html5/thumbnails/24.jpg)
Nursing Implications (cont’d)
Medications should be taken exactly as prescribed to have the maximum therapeutic effect
Overdosing can cause life-threatening problems
Blurred vision may cause problems with driving or operating machinery
![Page 25: CHAPTER 21 Cholinergic-Blocking Drugs Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc](https://reader035.vdocuments.net/reader035/viewer/2022062221/56649dba5503460f94aaa5d8/html5/thumbnails/25.jpg)
Nursing Implications (cont’d)
Patients may experience sensitivity to light and may want to wear dark glasses or sunglasses
When giving ophthalmic solutions, apply pressure to the inner canthus to prevent systemic absorption
![Page 26: CHAPTER 21 Cholinergic-Blocking Drugs Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc](https://reader035.vdocuments.net/reader035/viewer/2022062221/56649dba5503460f94aaa5d8/html5/thumbnails/26.jpg)
Nursing Implications (cont’d)
Dry mouth may occur; can be handled by chewing gum, frequent mouth care, and hard candy
Check with physician before taking any other medication, including over-the-counter medications
Antidote for atropine overdose is physostigmine
![Page 27: CHAPTER 21 Cholinergic-Blocking Drugs Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc](https://reader035.vdocuments.net/reader035/viewer/2022062221/56649dba5503460f94aaa5d8/html5/thumbnails/27.jpg)
Nursing Implications (cont’d)
Anticholinergics taken by the elderly patient may lead to higher risk for heatstroke because of the effects on heat-regulating mechanisms
Teach patients to limit physical exertion and avoid high temperatures and strenuous exercise
Emphasize the importance of adequate fluid and salt intake
![Page 28: CHAPTER 21 Cholinergic-Blocking Drugs Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc](https://reader035.vdocuments.net/reader035/viewer/2022062221/56649dba5503460f94aaa5d8/html5/thumbnails/28.jpg)
Nursing Implications (cont’d)
Patients should report the following symptoms to their physician: urinary hesitancy and/or retention, constipation, palpitations, tremors, confusion, sedation or amnesia, excessive dry mouth (especially if they have chronic lung infections or disease), or fever
![Page 29: CHAPTER 21 Cholinergic-Blocking Drugs Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc](https://reader035.vdocuments.net/reader035/viewer/2022062221/56649dba5503460f94aaa5d8/html5/thumbnails/29.jpg)
Nursing Implications (cont’d)
Monitor for therapeutic effects For patients with Parkinson’s disease:
fewer tremors and decreased salivation and drooling
For patients with urologic problems: improved urinary patterns, less hypermotility, increased time between voiding
Monitor for adverse effects