McKenna's Pharmacology for Nursing, 2e

33

Anticholinergic agents

Learning objectives Upon completion of the chapter, you should be able to: 1. Define anticholinergic agents. 2. Describe the therapeutic actions, indications, pharmacokinetics, contraindications and cautions, most common adverse reactions and important drug–drug interactions of anticholinergic agents. 3. Discuss the use of anticholinergic agents across the lifespan. 4. Compare and contrast the prototype drug atropine with other anticholinergic agents. 5. Outline the care considerations, including important teaching points, for people receiving anticholinergic agents.

Test your current knowledge of anticholinergic agents with a PrepU Practice Quiz!

Glossary of key terms anticholinergic: drug that opposes the effects of acetylcholine at acetylcholine receptor sites belladonna: a plant that contains atropine as an alkaloid; used to dilate the pupils as a fashion statement in the past; used in herbal medicine much as atropine is used today cycloplegia: inability of the lens in the eye to accommodate to near vision, causing blurring and inability to see near objects mydriasis: relaxation of the muscles around the pupil, leading to pupil dilation parasympatholytic: lysing or preventing parasympathetic effects

ANTICHOLINERGIC AGENTS/ PARASYMPATHOLYTICS atropine cyclopentolate

glycopyrrolate hyoscine hyoscyamine

ipratropium propantheline tiotropium

D rugs that are used to block the effects of acetylcho- line are called anticholinergic drugs. Because this action lyses, or blocks, the effects of the parasympathetic nervous system, they are also called parasympatholytic agents. This class of drugs was once very widely used to decrease gastrointestinal (GI) activity and secretions in the treatment of ulcers and to decrease other para- sympathetic activities to allow the sympathetic system to become more dominant. Today, more specific and less systemically toxic drugs are available for many of the conditions that would benefit from these effects. There- fore this class of drugs is less commonly used. Atropine

is the only widely used anticholinergic drug. Box 33.1 discusses the use of anticholinergics across the lifespan.

ANTICHOLINERGICS/ PARASYMPATHOLYTICS

Anticholinergic agents include atropine (generic), cyclo- pentolate ( Cyclogyl ), glycopyrrolate ( Robinul ), hyoscine (also known as scopolamine; Buscopan ), hyoscyamine ( Donnatab ) (not available in New Zealand), ipratropium