NSG 6005 Advanced Pharmacology Midterm—Study Guide

NSG 6005 Advanced Pharmacology Midterm—Study Guide There will be 75 questions on the Midterm. Most will be multiple choice. There are a couple True/False and 5 matching questions. I suggest you review your PowerPoints and Textbook Assignments. I hope this study guide is helpful Make sure you know the following topics very well. • When a medication is listed below, make sure you know all about it and how to apply it to different patient situations: What disease process it is used for?, how does it work?, when should it not be used?, adverse effects, pros/cons, interactions, patient education factors (should it be taken w/ food? At bedtime?), tapering, preliminary and post treatment labs, black box warnings/CI, etc. • If a disease process is mentioned below—know how to diagnose and recommended treatment guidelines. 1) General principles of pharmacokinetics and dynamics? PHARMACOKINETICS- What the body does to the drug” Absorption –Entry of drug to the blood stream. Usually depends on passive diffusion of drug through cell membranes. • Absorption depends on: blood flow at site, drugs lipid soluability (> lipic, > soluabililty that directly penetrate the memebrane), local PH and drug ionization (non-ionized absorb better), pharmaceutical processing (coatings and additives. • Blood brain barrier: allow lipid soluable only. May pump out any drug that it sees as foreign, hard to treat CNS infections. • Placenta: allows lipid drugs so does not protect from lipid soluable drugs, which is why pregnant women are limited to drugs. Know gestation age. • Distribution : fat ratio changes may alter distribution, especially a people age. • Fat soluable drugs may be accumulated: weight loss will release these drugs. • Water soluable drugs are affected by dehydration Biotransformation (Metabolism) : Drugs become more hydrophilic (water soluable) for excretion. • Also referred to as the P450 system or cytochrome P450 system. (a group of enzymes in the liver identified for their ability to breakdown drugs.) 2 • Hepatic “First Pass Effect” (parenteral (IV or IM) meds bypass this enzymatic effect) • breaks PO meds down to some degree, some are protected with coating but they don’t always work • Metabolites Usually less active, less toxic, easier • to excrete • Prodrugs - inactive in form given but metabolized to active drug (ex: enalapril) • Liver function determined by liver enzymes • Failing liver produces fewer enzymes, drugs available longer: caution • • Excretion: Process by which medications are eliminated from the body unchanged or as metabolites • Kidneys are main organ of excretion • If poor renal function, drug may accumulate, may wish to prescribe less of drug • Also eliminated via respiration, breast milk, defecation. Tears, sweat, saliva not as significant. • START LOW AND GO SLOW!!!! 3 PHARMOCODYNAMICS- “effect of drug on the body” Receptors: Drugs must bind to for effect o Help a process happen: agonist o Block a process from happening: antagonist o Know that: • All drugs have an effect • A drug’s ability to cause a response is called its efficacy • If you give a bigger dose you will get a bigger effect up to a point, most drugs have a ceiling. 2) CRITERIA FOR CHOOSING AND EFFECTIVE DRUG? • A.) Effectiveness: elicits responses for which it is given - most important • Safety: Cannot produce harmful effects even at very high dosages and for long time oNo such thing as completely safe drug • Selectivity: Only elicits response for which it is given, no side effects • No such thing as a selective drug, all have ADRs • Reversible action: most drugs should be reversible • Predictability: Know with certainty exactly how individual patient will respond – impossible, must individualize • Ease of administration: simple, convenient route - enhances compliance and decreases errors 4 • Freedom from drug interactions: few drugs are without drug interaction • Low cost: easy to afford; significant factor in adherence, esp. with elderly • Chemical stability: drugs ability to be stored for long time without loss of effectiveness – variable between drugs • Possession of simple generic name: easier to remember and less confusion amongst drugs 3) SYNERGISTIC EFFECT: When two or more drugs are given together they can react with each other: An effect arising between two or more agents, entities, factors, or substances that produces an effect greater than the sum of their individual effects. It is opposite of antagonism. o Can be positive (synergistic) • Morphine and Motrin o Can be negative (compete with each other) • Asa and Coumadin 4) Therapeutic drug levels: (not sure if this is correct) Minimal Effective Concentration (MEC) – plasma drug level below which therapeutic effects will not occur. Therapeutic Index or Range- margin of safety • •The wider or bigger it is, the safer the drug. o Example 1: Drug A: normal dose is 1 mg, toxic dose is 10 mg • Acetaminophen’s therapeutic range is 30 times the MEC o Example 2: Drug B: normal dose is 9 mg, toxic dose is 10 mg o Lithium’s therapeutic range is 3 times the MEC. 5) WHAT IS MEANT BY A SIGNIFICANT FIRST-PASS EFFECT? Metabolism is the process of changing one chemical into another. The 5 liver is a major organ for drug metabolism because it contains high amounts of drug-metabolizing enzymes and because it is the first organ encountered by drugs once they are absorbed from the GI tract. Metabolism by the liver following oral administration is called FIRST-PASS METABOLISM and is important in determining whether a drug can be orally administered. 6) HOW DO YOU KNOW HOW OFTEN TO PRESCRIBE A MEDICATION1/2 LIFE OF MEDICATIONS. • Half-life- amount of time it takes to reduce the plasma concentration by 50%. • In pharmacokinetics, steady state refers to the situation where the overall intake of a drug is fairly in dynamic equilibrium with its elimination. In practice, it is generally considered that steady state is reached when a time of 4 to 5 the half-life for a drug after regular dosing has started. 7) AGONISTS VERSUS ANTAGONISTS: AGONISTS: Drugs that produces a physiological response when combined with a receptor. ANTAGONISTS: a substance or drug that interferes with or inhibits the physiological action of another. 8) SUSTAINED RELEASE MEDICATION CONSIDERATIONS- implies slow release over time. It is defined as the type of dosage in which a portion of the drug is released immediately, and then the remaining/maintenance dose) is then released slowly by achieving a therapeutic level which is prolonged. 9) SUBLINGUAL MEDICATION ADVANTAGES. • Sublingual medication administration (under the tongue) and buccal (between the cheek and gum) allow drugs to have a more rapid onset of action and to avoid liver metabolism as they enter the blood stream. • Nitroglycerin given under the tongue can act within minutes to treat an angina attack. 10) FIRST STEP IN THE PRESCRIBING PROCESS ACCORDING TO WHO? • The first step in the prescribing process is an accurate diagnosis and a determination of a therapeutic objective. (page 29) 6 WHO SIX-STEP MODEL OF RATIONAL PRESCRIBING: STEP 1: DEFINE THE PATIENTS PROBLEM STEP 2: SPECIFY THE THERAPEUTIC OBJECTIVE STEP 3: CHOOSE THE TREATMENT STEP 4: START THE TREATMENT STEP 5: EDUCATE THE PATIENT STEP 6: MONITOR EFFECTIVENESS 11) THERAPEUTIC GOALS OF PRESCRIBING: Before deciding what medication to prescribe, it is important to clarify the therapeutic objective. • Is this goal to cure the disease • Relieve symptoms of the disease • Long term prevention • Is the goal treating the combination of 2 outcomes (pain and inflammation) • Palliative therapy • The provider should clarify whether the treatment goals are curative, symptom relieving or preventative. • Include patient in this stage as a partner of treatment. 12.) Patients at risk for adverse drug reactions. (page 55) • Genetic abnormalities • Age • Sex • Polypharmacy • Concomitant medical conditons • Children- are at higher risk primarily because medication