Chapter 1 psy185.pdf

The study of drug effects on: Mood Psychopharmacology Perception Cognition Behavior 1 Why is Psychopharmacology Important? Preva...

The study of drug effects on: Mood Psychopharmacology Perception Cognition Behavior 1 Why is Psychopharmacology Important? Prevalence of drug use Provides insight into human behavior Provides insight into therapeutic drug development 2 What is a Drug? , Administered substance that affects physiological functioning Drugs can take many forms Some substances that affect physiological functioning are not drugs Food, vitamins, nutritional supplements Some things found in the body can be drugs Testosterone, found in body, not considered a drug unless administered from an exogenous source 3 Why are Drugs Used? Instrumental drug use (most therapeutic drugs) Used to accomplish specific purpose Drinking coffee to wake up Taking pain meds to reduce headache Recreational drug use (drug dependence can arise here) Only used to experience drug effects Drinking alcohol to get intoxicated Using LSD to alter perception 4 Naming Drugs Trade names (Brand name) Trademarked name given by company that creates the drug Generic names Nonproprietary name, classifies drug in a category and distinguishes it from other drugs in that category Chemical names Street names 5  Objective effects-effects from drug that can be Psychoactive directly observed by others Drug Effects Subjective effects- those that cannot be directly observed 6 Pharmacology Pharmacodynamics Physiological actions of the drugs Pharmacokinetics How drugs are distributed, metabolized and eliminated from body Pharmacogenetics Studies how genetic differences influence the the pharmacodynamics and kinetics of drugs 7 Clinical Trials (Human Subjects) 8. Classification of Drugs Scheduled medications (potentially addictive) Class 1- Street drugs, no medicinal value Most addictive Class 2- Highly potential abuse but has medical value Most addictive of the medically used medications Includes oxycodone, hydrocodone, methylphenidate Class 3, 4,5- Lesser potential for abuse, class 3 higher potential, class 4 next highest, then class 5 Includes sleep medications, diazepam, alprazolam, testosterone supplements, some muscle relaxants Even includes certain over-the-counter oral nasal decongestant, Sudafed 9 Classification of Drugs Non-scheduled medications This includes all the other medications, they are not considered to have a high abuse potential This includes medications for high blood pressure, diabetes, heart disease, cancer, thyroid issues, cholesterol, etc. 10 Are these Classifications set in stone? Absolutely NOT! The FDA can move medications in and out of a class as they see fit based on data For example, a muscle relaxant called carisoprodol (Soma) was moved up from non-scheduled to scheduled in 2012 Vicodin (hydrocodone / apap) was upgraded from schedule 3 to schedule 2 in October 2014 after hydrocodone had been on market since early 1940’s 11 Classifications cont. There are certain medications that are non-scheduled now which could be in the future Just because it’s not scheduled now doesn’t mean it isn’t being abused Dextromethorphan Cyclobenzaprine (Flexeril) Gabapentin (Neurontin) 12 Let’s Cover the Basics Before getting into how drugs work, we need to be on the same page with some of the basics Neurons Cell membranes Proteins 13 The Basics The neuron (nerve cell) The cell body is also called the soma Most often, an electrical impulse flows from the dendrites, through the soma, down the axon, and out through the axon terminals The myelin sheaths help conduct the electric signal down the axon much more quickly 14 The Basics A nerve A nerve bundles up a lot of axons into an organized structure Axons can stretch over a great distance Some nerves have axons that carry information to the brain (sensory info.) Other nerves carry information from the brain (motor info.) 15 Looking closer at cell membranes Oil and water don’t mix Oil (fatty lipids, chains of hydrocarbons) will clump together in blobs to reduce the amount of fatty substance that comes into contact with water This simple process is what gives rise to the existence of cells The oil in water phenomenon is what is behind the foundation of cell walls (cell membranes) 16 Cell membrane Fatty hydrocarbons are the oil layer in the middle of membrane The yellow and orange spheres are phosphate groups that are “water loving”—they shield the oil layer from the water and this whole process naturally forms a cell wall This is called a phospholipid layer 17 Cell Membrane There are receptors, channels and other chemical entities that can be found in the cell membrane Receptors and channels are of particular importance to us when we are looking at action of drugs A membrane contains a large number of receptors and this number is fluid, that is the receptor number can go up or down 18 Proteins Generally speaking, these receptors and channels are made of proteins Proteins are made up of chains of amino acids These proteins can be very long chains which eventually fold on themselves to create a complicated structure Structure is critical to how the protein functions Structure is what allows these receptors to interact with medications Lock and key principle 19 One Last Thing Some terms to keep in mind: Hydrophilic: water loving Hydrophobic: water hating Lipophilic: fat or oil loving Lipophobic: fat or oil hating If a molecule is hydrophilic, it is also lipophobic Can’t be lipophilic too If a molecule is hydrophobic, it is also lipophilic Can’t be lipophobic too 20