Copyright © 2015 Cengage Learning® Chapter 13 Autonomic Nervous System Drugs
Copyright © 2015 Cengage Learning® Introduction Autonomic nervous system (ANS) –Automatic, self-governing, or involuntary No conscious control –Divided into sympathetic (alert system) and parasympathetic nervous system (resting and digesting system) Neurotransmitters: chemical substances released at nerve endings within these systems to transmit nerve impulses 2
Copyright © 2015 Cengage Learning® Introduction (cont’d.) Drugs that affect function of the autonomic nervous system –Adrenergics –Adrenergic blockers –Cholinergics –Cholinergic blockers 3
Copyright © 2015 Cengage Learning® Introduction (cont’d.) The following slides discuss various autonomic nervous system drugs –Refer to the chapter for specific actions, uses, side effects, contraindications, cautions, and interactions of each 4
Copyright © 2015 Cengage Learning® Adrenergics Sympathetic nervous system –Emergency system used to mobilize the body for quick response and action –Key words: fright, fight, or flight What are adrenergics? –Drugs that mimic the action of the sympathetic nervous system 5
Copyright © 2015 Cengage Learning® Adrenergic Blockers Drugs that block the action of the sympathetic nervous system –Most commonly used drugs in this category are the alpha- and beta-adrenergic blockers, or alpha-blockers and beta-blockers Alpha-adrenergic blockers are discussed in Chapters 15 and 25 Prototype of the beta-adrenergic blockers is propranolol (Inderal) 6
Copyright © 2015 Cengage Learning® Cholinergics What do parasympathetic nerve fibers do? –Synthesize and liberate acetylcholine as the mediator What are cholinergics? –Drugs that mimic the action of the parasympathetic nervous system 7
Copyright © 2015 Cengage Learning® Cholinergic Blockers What are cholinergic blockers? –Drugs that block the action of the parasympathetic nervous system Also called parasympatholytic –Common use of anticholinergics is scopolamine transdermal patches Treat or prevent sea-sickness by decreasing gastric secretions and motility 8
Copyright © 2015 Cengage Learning® Cholinergic Blockers (cont’d.) Anticholinergics are most commonly used as preoperative medications –Atropine and glycopyrrolate (Robinul) Reduce secretions of the mouth, pharynx, bronchi, and GI tract and reduce gastric activity –Used to prevent cholinergic effects during surgery, such as hypotension or bradycardia and some cardiac arrhythmias associated with general anesthetics or vagal stimulation 9