Anticholinergic Agents Chapter 33: Anticholinergic Agents

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

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

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

Use of Anticholinergic Agents Across the Lifespan

Pharmacodynamics of Anticholinergic Drugs

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

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)

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

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

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

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

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

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

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

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

Prototype Anticholinergic Drugs

Prototype Anticholinergic Drugs (Continued)

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

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