MODULE: INTRODUCTION TO PHARMACOLOGY

1 Transcripts MODULE: INTRODUCTION TO PHARMACOLOGY . INTRODUCTION Welcome to PHARMACOLOGY Made Easy, a learning tool that focuses on essential information about drugs that you'll commonly encounter in nursing practice. Drugs are organized by the nine body systems-- neurological, musculoskeletal, respiratory, cardiovascular, hematologic, gastrointestinal, reproductive and genitourinary, endocrine, and immune, as well as drugs for pain and inflammation and infection. This will help you understand how the drugs affect the human body, plus the presentation facilitates memorization of crucial details about each drug. For each category, you'll receive a prototype drug along with its expected pharmacological action, adverse drug reactions, interventions, administration considerations, client instructions, contraindications, and precautions and interactions. Drug information tables for each prototype drug recap this information in a quick reference format.

2 And safety alerts draw your attention to important safety considerations. Each module includes 10 drill questions and a case study that illustrates and reinforces information about drugs in the module. In addition, each module has a 25-item practice test to check your understanding of the module content. This introductory module is an overview of the information you'll learn about the drugs in PHARMACOLOGY Made Easy and will help you master this important content. Absorption Absorption, absorption is the movement of the drug from the site of administration to the various tissues of the body. For example, oral drugs most absorbed through the intestinal wall, and enter the portal vein before passing through the liver, and into the body's circulation. Parental role drugs absorbed either directly through a vein or indirectly through muscle or subcutaneous tissue, enter the blood, and then pass through the liver. Metabolism of drugs primarily takes place in the liver.

3 Since part of the drug may deactivate when it passes through the liver, the actual amount available to the body can be less than what the client originally ingests. This is called the first pass effect. Bioavailability is the amount of drug available after passing through the liver. Distribution Distribution, distribution is movement of the drug by the circulatory system to its intended site of action. Drugs enter the blood after they absorb through the intestinal wall or alveoli in the lungs, or after direct or indirect injection. Areas of the body that have a rich blood supply, such as the liver, kidneys, and heart receive the highest level of the drug. Areas of the body that do not have a rich supply of blood, such as the bones, or areas that have a natural barrier, such as the brain's blood brain barrier, won't receive a very high level of the drug. 1 Assessment Technologies Institute: PHARMACOLOGY Made Easy Transcripts Excretion Excretion is the elimination of a drug or its metabolites through various parts of the body.

4 For instance, the kidneys eliminate many drugs through the urine. The kidneys may even reabsorb some of the drug through the kidneys, allowing it to pass through the body again before excretion actually occurs. Excretion can also occur through the gastrointestinal tract, the skin, or the lungs. Drug-Drug Interactions Drug- drug interactions occur when one drug changes the way another drug affects the body. When the combined effect of two drugs you give together is the same as each drug you give alone in similar doses, an additive effect occurs. This results in a 1 plus 1 equals 2 effect. For example, when a client takes two drugs that are central nervous system depressants, such as alcohol and opioids, their effects add to each other in a 1 plus 1 equals 2 manner, putting the client at risk for significant and possibly fatal central nervous system depression. Synergistic effects occur when the effect of one drug is greater if you give it with another drug.

5 This results in a 1 plus 1 equals more than two effect. For example, when you give aspirin with the prescription blood thinner Warfarin, the effects of Warfarin intensify and severe bleeding can occur. Antagonistic effects occur when the effect of one drug is decreased or blocked if you give it with another drug. This results in a 1 plus 1 equals less than two effect. For example, if you give a drug for asthma to open a client's airway and another drug for its cardiovascular effects that has an adverse drug reaction that constricts the client's airways, the effect of the second drug antagonizes or interferes with the action of the first drug, getting a 1. plus 1 equals zero effect. Drug-Food Interactions Drug-food interactions occur when a food changes the way a drug affects the body. This can result in increased levels of the drug in the body, which occurs when food increases the amount of a drug the body absorbs or the rate at which it is metabolized.

6 Grapefruit juice, which inhibits an enzyme in the liver that facilitates drug metabolism, can increase the amount of a drug in the body because it no longer breaks down in the liver. This effect occurs if a client takes a drug with grapefruit juice, as well as several hours after drinking grapefruit juice. For this reason, there are several drugs that require clients to avoid drinking grapefruit juice during therapy. Drug-food interactions can also result in decreased levels of the drug in the body, which occurs when food decreases the rate or amount of a drug the body absorbs. The rate at which it is metabolized counteracts the actions of the drug. Clients taking the blood thinner warfarin might see a decrease in the effects of the drug if he or she eats spinach. Spinach contains vitamin K, which enhances the action of certain clotting factors, counteracting the effects of warfarin. 2 Assessment Technologies Institute: PHARMACOLOGY Made Easy Transcripts MODULE: NEUROLOGICAL SYSTEM 1.

7 INTRODUCTION Welcome to the neurological system one module. In this module, you'll first review the structures and functions of the central nervous system, brain and spinal cord, and the peripheral nervous system, cranial nerves, spinal nerves, and autonomic nervous system. You'll then learn about central nervous system depressants and stimulants and common uses for these medications. Finally, you'll learn about drugs that provide neuronal support for degenerative neurological disorders such as Parkinson's disease and Alzheimer's disease. The Nervous System The nervous system has two main segments-- the central nervous system and the peripheral nervous system. The brain and spinal cord make up the central nervous system. The peripheral nervous system includes the cranial and spinal nerves and the autonomic nervous system. Afferent sensory nerves send information to the spinal cord and brain. And efferent motor nerves carry signals from the brain to all parts of the body.

8 The autonomic nervous system includes the sympathetic nervous system and the parasympathetic nervous system. The sympathetic nervous system protects the body in times of danger and stress. The parasympathetic nervous system maintains the regulatory tasks of the body. The Brain Four lobes make up each hemisphere of the brain. They are the frontal, temporal, parietal, and occipital lobes. The cerebellum and brain stem provide additional support to the brain and its functions, and facilitate communication between the brain and other parts of the body. An interlocking network of neurons allows the brain to communicate to various parts of the body via nerves in the spinal cord. Chemical neurotransmitters stimulate neurons to send electrical impulses from one neuron to the next. Neurons and Neurotransmitters Neurons are cells that conduct nerve impulses in the central and peripheral nervous systems. Neurons consist of a cell body, axon, and dendrites.

9 The cell body contains cytoplasm, mitochondria, lysosomes, and other structures necessary for the cell to survive. Dendrites protrude from the cell body receiving and carrying nerve impulses to the cell body. The axon is a thread-like structure that carries nerve impulses away from the cell body. Axons have multiple appendages that reach out to dendrites on neighboring cell bodies. The synaptic cleft is the space between the axons appendages and the neighboring cell's dendrites. Electrochemical reactions release neurotransmitters across that gap. The reaction occurs in response to the depolarization that occurs when sodium and potassium ions are exchanged across the axon membrane. Calcium ions regulate the flow of ions through the membrane. The axon of one neuron releases chemicals, called neurotransmitters, onto the dendrites of another neuron. Some neurotransmitters found in the central nervous system are acetylcholine. Histamine. Gamma-aminobutyric acid, or GABA.

10 Oxytocin. Vasopressin. And the monoamines-- dopamine, serotonin, epinephrine, and norepinephrine. The central and peripheral nervous systems contain many other neurotransmitters, but this module only covers these transmitters. 3 Assessment Technologies Institute: PHARMACOLOGY Made Easy Transcripts Case Study HCP LIBERTY : Morning. My name is Liberty and I'm just going to ask you a few questions before I do my assessment. Would you mind telling me your full name and date of birth, please? PATIENT: Kelly Smithson, July 3rd, 1975. HCP LIBERTY: Okay, thank you. Mrs. Smithson, do you know where you are? PATIENT: I was at home. HCP LIBERTY: Okay. You're at the hospital now. Can you tell me what date it is? PATIENT: I can't remember. HCP LIBERTY: That's okay. Okay, I'm just going to check your breathing. If you wouldn't mind taking a deep breath for me please. Okay, thank you, and another one. Alright. Okay, again. Alright, and one more for me please.