Action: Anticholinergics inhibit the muscarinic actions of acetylcholine at receptor sites in the autonomic nervous system; anticholinergics are also known as antimuscarinic drugs.

Uses: Anticholinergics are used for a variety of conditions: gastrointestinal anticholinergics are used to decrease motility (smooth muscle tone) in the GI, biliary, and urinary tracts and for their ability to decrease gastric secretions (propantheline, glycopyrrolate); decreasing involuntary movements in parkinsonism (benzotropine, trihexyphenidyl); bradydysrhytmias (atropine); nausea and vomiting (scopolamine); and as cyclopegic mydriatics (atropine, hematropine, scopolamine, cyclepentolate, tropicamide).

Side effects / Adverse reactions: The most common side effects are dry mouth, constipation, urinary retention, urinary hesitancy, headache, and dizziness. Also common in paralytic ileus.

Contraindications: Persons with narrow-angle glaucoma, myasthenia gravis, or GI/GU obstruction should not use some of these products.

Precautions: Anticholinergics should be used with caution in patiens who are elderly, pregnant, or lactating or in those with prostatic hypertrophy, CHF, or hypertension; use with caution in presence of high environmental temp.

Interactions: Increased anticholinergic effects may occur when used with MAOIs and tricyclic antidepressants and amantadine. Anticholinergic may cause a decreased effect of phenothiazines and levodopa.

Possible nursing diagnoses:
» Decreased cardiac output [uses]
» Constipation [adverse reactions]
» Knowledge deficit [teaching]

Nursing Considerations

» I/O ratio; retention commonly causes decreased urinary output
» Urinary hesitancy, retention; palpate bladder if retention occurs
» Constipation; increase fluids, bulk, exercise if this occurs
» For tolerance over long term therapy, dose may need to be increased or changed
» Mental status: affect, mood, CNS depression, worsening of mental symptoms during early therapy

» Parenteral dose with patient recumbent to prevent postural hypotension
» With or after meals to prevent GI upset; may give with fluids other than water
» Parenteral dose slowly; keep in bed for at least 1 hour after dose; monitor vital signs
» After checking dose carefully; even slight overdose can lead to toxicity

» Storage at room temperature
» Hard candy, frequent drinks, sugarless gum to relieve dry mouth

» Therapeutic response: decreased secretions, absence of nausea and vomiting

Teach patient/family:
» To avoid driving or other hazardous activities; drowsiness may occur
» To avoid OTC medication: cough, cold preparations with alcohol, antihistamines unless directed by prescriber

Selected Generic Names

Scopolamine (transdermal)