Chapter 3 Autonomic Nervous System Drugs

3 Autonomic Nervous System Drugs Educational Objectives After reading this chapter, the reader should be able to: 1. Understand the differences between the sympathetic and parasympathetic divisions of the autonomic nervous system. 2. Illustrate the different types of receptors and neurotransmitters in the autonomic nervous system. 3. Identify drugs affecting the autonomic nervous system (sympathetic and parasympathetic divisions). 4. Understand the differences between adrenergic and cholingeric drugs. 5. Describe the role of autonomic nervous system drugs in dentistry. 6. Explain the use of vasoconstrictors (in local anesthetics) in dental patients. Lecture Outline I. The Nervous System A. Biochemistry. 1. Neurotransmitters. 2. Synthesis and metabolism of catecholamines. B. Sympathetic division. 1. Flight-or-fight response. 2. Functions. 3. a and b receptors. C. Parasympathetic division. 1. Rest-and-digest division. 2. Functions. 3. Nicotinic and muscarinic receptors. II. Cholinergic or Parasympathetic Drugs A. Cholinergic agonists. 1. Direct-acting. a. Acts like acetylcholine at receptor sites. b. Drug interactions. 2. Indirect-acting. a. Nerve gases. b. Drugs of glaucoma. c. Drugs of Alzheimer’s disease. B. Anticholinergics 1. Functions. 2. Oral side effects. 3. Drug interactions. C. Sympathomimetics (adrenergic agonists). 1. Binds to adrenergic receptors. 2. Therapeutic uses. 3. a1, a2, b1, b2 drugs. D. Sympatholytics (adrenergic antagonists). 1. Therapeutic uses. 2. Adverse effects. 3. Drug interactions. Teaching Tips 1. Impress upon the students the use of autonomic drugs in dentistry. 2. Review the importance of knowing the fundamentals of the autonomic nervous system because many drugs and medical conditions are related to receptors and neurotransmitters in the ANS. 3. Explain to the students about the vasoconstrictors epinephrine and levonordefrin in dental local anesthetics and management in medically compromised dental patients. 4. Discuss the parasympathetic system and corresponding drugs during one classroom session and then discuss the sympathetic system and corresponding drugs at another session. This will be less confusing for the student. 5. Develop a matching game using receptors and drugs from the sympathetic and parasympathetic divisions.Factoids 1. Many OTC cold, cough, or sinus drugs likely contain autonomic agents. 2. Nerve impulses travel as fast as 250 miles per hour. 3. The human body has 47 miles of nerve pathways.Discussion Questions 1. What are the effects of epinephrine in the body of a healthy patient and a cardiac patient? 2. Discuss drug interactions that may occur with epinephrine (contained in local anesthetics). 3. Discuss the difference between a nonselective beta-blocker and a selective beta-blocker in the treatment of hypertension. Emphasize the precautions with the use of epinephrine with these drugs. 4. Discuss the types of drugs used in the management of Alzheimer’s disease. 5. Discuss the actions of nicotine, which is used in smoking-cessation products.Classroom Activities 1. Divide the students in groups. Assign each group to list the functions of the sympathetic nervous system and drugs (give the drug name to each group) that affect that division (both sympathomimetics and adrenergic blockers). Emphasis should be placed on dental drugs in this classification. 2. Divide the students in groups. Assign each group to list the functions of the parasympathomimetic nervous system and drugs that affect that division (parasympathomimetics and anticholinergics). Emphasis should be placed on dental drugs in this classification. 3. Discuss the dental implications of using autonomic drugs. 4. Have students develop a drug instruction sheet for patients receiving a cholinergic drug for xerostomia. 5. Create flash cards for the different classes of autonomic drugs.Multimedia Found in the PowerPoint Lecture Outline Animations 1. Brain © 2013 by Education, Inc. Weinberg, Instructor’s Resource Manual for Oral Pharmacology for the Dental Hygienist, 2nd Edition