Chapter 33: Anticholinergic Agents

1. Chapter 33: Anticholinergic Agents

2. Anticholinergic Drugs • Action • Used to block the effects of acetylcholine • Lyse, or block effects of the PNS; also called parasympatholytic agents • Uses (better drugs are available now) • Decrease GI activity and secretions (treat ulcers) • Decrease parasympathetic activities to allow the sympathetic system to become more dominant

3. Anticholinergics/Parasympatholytics • Derived from the plant Belladonna • Block only the muscarinic effectors in the PNS and cholinergic receptors in the SNS • Act by competing with acetylcholine for the muscarinic acetylcholine receptor sites • Do not block the nicotinic receptors • Have little or no effect at the neuromuscular junction

4. Effects of Blocking the Parasympathetic System • Increase in heart rate • Decrease in GI activity • Decrease in urinary bladder tone and function • Pupil dilation • Cycloplegia

5. Use of Anticholinergic Agents Across the Lifespan

6. Pharmacodynamics of Anticholinergic Drugs

7. Anticholinergic Agents and Their Indications • Atropine -Blocks parasympathetic effects in many situations • Depresses salivation and bronchial secretions • Dilates the bronchi • Inhibits vagal responses in the heart • Relaxes the GI and genitourinary tracts • Inhibits GI secretions • Causes mydriasis • Causes cycloplegia

8. Anticholinergic Agents and Their Indications • Dicyclomine (Antispas, Dibent, and others) • Relaxes GI tract; treats hyperactive or irritable bowel • Glycopyrrolate (Robinul) • Adjunct in the treatment of ulcers • Propantheline (Pro-Banthine) • Adjunct in the treatment of ulcers

9. Anticholinergic Drugs • Actions • Blocks the acetylcholine receptors at the muscarinic cholinergic receptor site • Indications • Decrease secretions • Restore cardiac rate and blood pressure • Pylorospasm and hyperactive bowel • Relax uterine hypertonicity

10. Anticholinergic Drugs (cont.) • Pharmacokinetics • Well absorbed • Widely distributed throughout the body • Cross the blood brain barrier • T ½ varies based on route and drug • Excreted in the urine

11. Anticholinergic Drugs (cont.) • Contraindications • Known allergy • Any condition that could be exacerbated by blocking of the parasympathetic nervous system • Glaucoma • Peptic ulcer disease • Prostatic hypertrophy • Bladder obstruction

12. Anticholinergic Drugs (cont.) • Caution • Breast feeding • Spasticity and brain damage

13. Anticholinergic Drugs (cont.) • Adverse Reactions • Blurred vision • Mydriasis • Cycloplegia • Photophobia • Palpitations, bradycardia • Dry mouth, altered taste perception • Urinary hesitancy and retention • Decreased sweating; predisposition to heat prostration

14. Anticholinergic Drugs (cont.) • Drug-to-Drug Interaction • Any other drug with anticholinergic activity • Antihistamines • Antiparkinson’s drugs • Phenothiazines • MAOI’s and tricyclic antidepressants

15. Nursing Considerations for Anticholinergic Drugs • Assess: • History and Physical Exam • Known allergy, glaucoma; stenosing peptic ulcer, intestinal atony, paralytic ileus, GI obstruction, severe ulcerative colitis, and toxic megacolon; • Prostatic hypertrophy and bladder obstruction; cardiac arrhythmias, tachycardia, and myocardial ischemia • Myasthenia gravis, pregnancy, impaired renal and hepatic function

16. Nursing Considerations for Anticholinergic Drugs Cont. • Assess: • Neurological status, including level of orientation, affect, reflexes, and papillary response • VS, CV status, ECG as appropriate • Bowel and bladder patterns • Renal function labs as appropriate

17. Prototype Anticholinergic Drugs

18. Prototype Anticholinergic Drugs (Continued)

19. Question In which group of patients would the healthcare provider use caution in prescribing anticholinergic medications? A. Patients with spasticity B. Patients with myasthenia gravis C. Patients with Parkinson’s disease D. Patients with hyperactive reflexes

20. Answer A. Patients with spasticity Rationale: Caution: Breast feeding; spasticity and brain damage