This is Part 1 of 4 Video Lectures on AUTONOMIC DRUGS by Professor Fink. In this Video Lecture, Professor Fink describes [1] the Parasympathomimetic (muscarinic Cholinergic Agonist) Drugs and [2] the Parasympatholytic (muscarinic Cholinergic Antagonist) Drugs. Prototype Drugs are cited and their mechanism of action, clinical uses & adverse effects are explained. Reference is made to cevimeline (Evoxac), Sjogren’s Syndrome, pilocarpine, Glaucoma, atropine, belladonna alkaloids, enuresis, IBS, & ipratropium (Atrovent). Any drug that works by blocking the “muscarinic” ACh Receptor sites will block the parasympathetic actions on the visceral organs. This allows the sympathetic autonomic motorneurons to exert the dominant effect ON THE VISCERAL ORGANS. IN ADDITION, any drug that works by blocking the “muscarinic” ACh Receptor sites will ALSO BLOCK THE ACTION OF ACh IN THE CNS (BRAIN). In the CNS, ACh is primarily EXCITATORY. This causes an overall decrease in electrical activity in the Brain, causing drowsiness & lethargy. YES; on the surface it looks a paradox: “Stress state” on the VISCERAL ORGANS (peripheral action), but drowsiness in the Brain (central action)! BUT it is all based on blocking the muscarinic ACh Receptor sites: (1) on the visceral organs and (2), in the Brain. Thus, drugs that block muscarinic ACh Receptor sites, like atropine, or many drugs with “atropine-like” actions (including Antihistamines) cause CENTRAL sedation (drowsiness) and are even used to slow-down electrical activity in the Vestibular (Balance) Reflex Center and Vomiting Reflex Center and are prescribed to reduce “motion sickness” (such as meclizine & cyclizine.) Check-out professor fink’s web-site or additional resources in Biology, Anatomy, Physiology & Pharmacology: www.professorfink.com Down-loadable e-Books of the Lecture Outlines by Professor Fink can be purchased from the WLAC Bookstore at: https://wlac.redshelf.com/ “Hard Copy” Lecture Outlines can be purchased from the WLAC Bookstore at: http://onlinestore.wlac.edu/fink.asp