Pharmacology Handout

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<p>PHARMACOLOGYPharmacology Study or science of drugs</p> <p>Toxicology Study of the adverse effects of drugs and other chemicals on living systems Toxic effects are often an extension of a drugs therapeutic action Pharmacognosy Study of natural (vs synthetic) drug sources (both plants and animals) PHARMACOKINETICS</p> <p>3 Basic Areas of Pharmacology Pharmaceutics Pharmacokinetics Pharmacodynamics</p> <p>Absorption Pharmaceutics Distribution Study of how various dosage forms (e.g., injection, capsule, controlled release tablet) influence the way in which the body metabolizes a drug and the way in which the drug affects the body Pharmacokinetics Study of what the body does to the drug molecules Involves absorption, distribution, metabolism and excretion Pharmacodynamics Study of what the drug does to the body Involves drug-receptor interactions Receptor Theory Pharmacotherapeutics Focuses on the use of drugs and the clinical indications for administering drugs to prevent and treat diseases Defines the principles of drug actions (the cellular processes that change in response to the presence of drug molecules) Empirical therapeutics drug therapy that is effective but for which the mechanism of action (MOA) is unknown Rational therapeutics drug therapy in which specific evidence has been obtained for the mechanisms of drug action Metabolism (biotransformation) Excretion A. Absorption Rate at which and extent to which a drug moves from its site of administration Factors affecting the rate and efficacy of absorption Route of administration Blood flow Surface area available Solubility of the drug Drug interactions pH (acidity (&gt;uncharged) and alkalinity affects absorption) Bioavailability The fraction or biologic fluid of the administered drug that gains access to its site of action IV injected blood 100%</p> <p>NOT IV injected - &lt; 100% Factors affecting Bioavailability First pass metabolism biotransformation that occurs before the drug reaches its site of action (MC site - liver)</p> <p>1</p> <p>All of the factors affecting absorption: pH, blood flow, drug interactions, route of administration Routes of Drug Administration</p> <p>Liquid for Injections liquid with no particulate matter Epinephrine</p> <p>Alimentary (Oral, Buccal, Sublingual, Rectal/Suppository) Parenteral (Intravenous, intramuscular, subcutaneous, intrathecal) Inhalation Topical Subcutaneous Routes of Administration Sublingual Under the tongue Nitroglycerin Oral The drug is swallowed and absorbed through the stomach and intestinal tract Oral Glucose Aspirin Inhalation a gas or aerosol inhaled by the patient Oxygen by mask Albuterol by hand-held metered- dose inhaler or by small-volume nebulizer Injection The drug is injected into a muscle mass Epinephrine by auto-injector</p> <p>Medication Forms Gel viscous substance that the patient swallows Oral Glucose Suspension drug particles mixed in a solute Activated Charcoal Fine powder for Inhalation a crystalline solid mixed with liquid to form a suspension Albuterol by hand-held metered-dose inhaler Gas Oxygen by mask Spray Nitroglycerin sub-lingual spray Liquid/vaporized Albuterol by small-volume nebulizer B. Distribution Process by which a drug leaves the bloodstream and enters the interstitium or the cells of the tissues Passive diffusion, transport o special carrier proteins, active transport C. Metabolism/ Biotransformation</p> <p>Medication Forms Tablets compressed powder shaped into a disk Aspirin Nitroglycerin Liver, (cytochrome P450 enzymes) skeletal muscle, kidneys, lungs, plasma and intestinal mucosa Involves the biochemical alteration of a drug into an inactive metabolite, a more soluble compound or a more potent active metabolite</p> <p>2</p> <p>D. Excretion Process by which a drug or metabolite is removed from the body Renal (MC), fecal, respiratory, breast milk, skin Half life The time required for half of an administered dose of drug to be eliminated by the body aka elimination half-life Steady state Physiologic state in which the amount of drug removed via elimination is equal to the amount of drug absorbed with each dose Onset of action Time required for the drug to elicit a therapeutic response Peak effect Time required for a drug toto reach its maximum therapeutic response Duration of action Length of time that the drug concentration is sufficient (without more doses) to elicit a therapeutic response Peak level highest blood level Trough level lowest drug level Enzyme Substance that catalyzes biochemical reactions in a cell Agonist A drug that binds to and stimulates the activity of one or more biochemical receptor types in the body Antagonist A drug that binds to and inhibits the activity of one or more more biochemical receptor types in the body</p> <p>Theurapeutic index Ratio of a drugs toxic level to the level that provides therapeutic benefits Drug interaction Alteration of the action of one drug by another Synergistic effects Occur when two drugs administered together interact in such a way that their combined effects are greater than the sum of the effects for each drug given alone Antagonistic effects Occur when the combination of two drugs results in drug effects that are less than the sum of the effects for each drug given separately Rights of Medication Use Right patient Right drug Right time Right route Right dose Right documentation Right assessment Right education Right evaluation Right to refuse Effects The desired result of administration of a medication Side Effects Effects that are not desired and that occur in addition to the desired therapeutic effects Medication error A preventable situation in which there is a compromise in the five rights of medication use Adverse Drug Reaction (ADR) Any reaction to a drug that is unexpected and undesirable and occurs at therapeutic drug dosages</p> <p>3</p> <p>Allergic Reaction Aka as hypersensitivity reaction An immune response wherein various chemical mediators (histamine, cytokines, other inflammatory substances) are released Immunoglobulins recognize the drug, its metabolite or another ingredient in a drug formulation as a dangerous foreign substance; they bind to the substance in an attempt to neutralize it Can result in mild reactions (skin erythema or rashes) or to severe/ life threatening reactions (constriction of bronchial airways and tachycardia) Idiosyncratic reaction Not the result of a known pharmacologic property of a drug or of a patient allergy but instead occurs unexpectedly in a particular patient Genetically determined abnormal response to normal dosages of a drug (ex, deficiency or excess of an enzyme) Teratogenic effects result in structural defects in the fetus Mutagenic effects permanent changes in the genetic composition of living organis; consist of alterations in chromosome structure, the number of chromosomes, or the genetic code of the DNA Carcinogenic effects cancer-causing effects of drugs, other chemicals, radiation and viruses Indication The reason for administering a medication or performing a treatment Contraindication A factor that prevents the use of a medication or treatment (eg. Allergies) Dose The amount of a drug to be administered at one time Mechanism of Action How a drug works</p> <p>Medication Names Chemical Name describes the drugs chemical structure Generic Name reflects the chemical name, but in shorter form Trade Name the name the manufacturer uses to market the drug Official Name the name used in the U.S. Pharmocopoeia</p> <p>Steps in Administering Medication Obtain an Order Confirm Order Steps in Administering Medication Select Proper Medication Avoid contamination Check Expiration Date Check For Signs of Contamination Discoloration Cloudiness Particulate Matter Verify Form &amp; Route Inform Patient of Order Inquire about allergies Recheck Medication Expiration date Contamination At least two more times after initial check Assess Patient prior to administration of the drug Administer the correct dose by the correct route Dispose of Contaminated Equipment Reassess After Administration</p> <p>COMMONLY USED ABBREVIATIONS a.c. ante cibum before meals p.c. post cibum after meals ad. lib. ad libitum as desired od omni die once a day bid bis in die twice a day tid</p> <p>4</p> <p>ter in die three times a day qid quarter in die Four times a day ADL Activities of daily living hs hora somni hours of sleep OD oculus dexter right eye OS oculus sinister left eye OU oculus uterque both eyes o.m. omni mane every morning n.p.o. nulla per orem nothing by mouth q.h. quaque hora every hour p.r.n. pro re nata as necessary stat statim immediately Systems of Measurement Common Household Measurement 1 quart 1 pint 1 cup 1 tbsp 1 tsp Apothecary Measurements 60 minims = 8 fluidrams = or 480 minims 16 fluid ounces = 2 pints 4 quarts Metric Measurements Units of volume (liter) 1 mL</p> <p>1 dL 1 decaliter</p> <p>= =</p> <p>.1 L 10 Liters</p> <p>Units of weight (gram) 1 mcg = .000001 gm 1 mg = .001 gm 1 cg = .01 gm 1 dg = .1 gm 1 kilogram = 1000 grams Other units 1 gm. = 15 gr. 1 gr = 60 mg 1 mg = 1,000 mcg 1 mL = 1 cc; 15 gtts; 1 gram 60 mcgtts 1L = 1 qt; 1000 mL 1 gal = 4 L; 4 qt., 4000 mL 1 ounce = 30 gm., 30 cc 1 kg = 2.2 lbs 1 lb = 16 ounces REVIEW OF THE AUTONOMIC NERVOUS SYSTEM Nervous System 1.Central Nervous System 2. Peripheral Nervous System Peripheral Nervous System 1.Somatic Nervous System (innervates skeletal muscle) 2.Autonomic Nervous System (ANS) collection of nuclei, cell bodies, nerves, ganglia, and plexuses that provides afferent and efferent innervation to smooth muscle and visceral organs of the body; regulates functions that are not under conscious control BP, HR and intestinal motility) Autonomic Nervous System (ANS) 1 fluidram 1 fluid ounce 1.Sympathetic Nervous System- originates in the thoracolumbar portion of the spinal cord 2.Parasympathetic Nervous System originates from the cranial nerve nuclei III, VII, IX, X as well as the 3rd and 4th sacral spinal roots</p> <p>= 4 cups = 2 cups =8ounces =3 tsp; 15 mlL =60 gtts;5mL</p> <p>= =</p> <p>1 pint 1 quart 1 gallon</p> <p>=</p> <p>.001 L</p> <p>5</p> <p>Sympathetic Nervous System Flight or fight situations HR increases BP rises Eyes dilate Blood sugar / glucoses rises Bronchioles expand Blood flow shifts from the skin to skeletal muscles Sympathetic Nervous System Receptors: Adrenergic Receptors- alpha 1 alpha 2 beta 1 beta 2 Dopamine Receptors Parasympathetic Nervous System Rest and digest system Slows HR Lowers BP Increases intestinal activity Constricts pupils Empties urinary bladder Receptors: Cholinergic receptors muscurinic nicotinic Neurotransmitters Major NT in the ANS Acetylcholine cholinergic transmission Norepinephrine adrenergic transmission ANS drugs achieve their effects by acting as either agonists or antagonists at cholinergic and adrenegic receptors DRUGS Cardiovascular Drugs Positive Inotropic Drugs Antidysrhythmic Drugs Antianginal Drugs Antihypertensive Drugs Antilipemic Drugs Coagulation Modifier Drugs Anticoagulants Antiplatelet drugs Antifibrinolytic drugs Thrombolytic Drugs Drugs Affecting the Renal System Diuretic Drugs Endocrine Drugs Thyroid and Antithyroid Drugs Antidiabetic Drugs Adrenal Drugs Drugs Affecting Reproductive Functions Respiratory Drugs Antihistamines, Decongestants, Antitussives and Expectorants Bronchodilators and others Antiinfective Drugs Antibiotics Antiviral Drugs Antitubercular Drugs Antifungal Drugs Others Antiinflammatory and Antirheumatic Drugs GIT Drugs Acid-controlling Drugs Antidiarrheals and laxatives Antiemetics and Antinausea Drugs Vitamins and Minerals/ Nutrition Supplements Drugs affecting the CNS Analgesic Drugs General and Local Anesthetics CNS Depressants and Muscle Relaxants Antiepileptic Drugs Antiparkinsonian Drugs Psychotherapeutic Drugs CNS Stimulants and Related Drugs Drugs Affecting the Autonomic System Adrenergic Drugs Adrenergic-Blocking Drugs Cholinergic Drugs Cholinergic-Blocking Drugs Immunosuppressant and Antineoplastic Drugs OTHERS: Hematologic, Dermatologic, Ophthalmic and Otic Drugs Cardiovascular Drugs Drugs used to improve CV function include: Inotropic drugs Antiarrhtymic drugs Antianginal drugs Antihypertensive drugs</p> <p>6</p> <p>Diuretics Antilipemic drugs Inotropic drugs Influence the contractility of muscular tissue (increase the force of hearts contarction) POSITIVE INOTROPIC 2 types: 1. cardiac glycosides - slow the heart rate (negative chronotropic effect) - slow electrical impulse conduction (negative dromotropic effect) 2. phosphodiesterase (PDE) Cardiac Glycosides Group of drugs derived from digitalis ( foxglove plants) Digoxin most common prototype of cardiac glycosides Pharmacokinetics: Capsules are absorbed most efficiently Followed by elixir then tablets Poorly bound to plasma proteins Most of the drugs is excreted by the kidneys unchanged Pharmacodynamics: It boosts intracellular clacium at the cell membrane Enhance the movement of calcium into the myocardial cells and stimulate the release, or block the reuptake, of norepinephrine at the adrenergic nerve terminal Acts on CNS Pharmacotherapeutics: Heart failure, supraventricular arrhtymias, paroxysmal atrial tachycardia y Assessment: 1. Obtain Hx 2. Monitor drug effectiveness take apical pulse for 1 minute before each dose 3. Monitor digoxin levels (therapeutic blood levels- 0.5 to 2 ng/ml) 4. Obtain blood for digoxin levels 8 hours after the last dose by mouth 5. Closely monitor K levels y Intervention: 1. Before giving a loading dose, obtain a baseline 2. Take the apical pulse before giving this meds</p> <p>3.</p> <p>4.</p> <p>Wihthold the drug and notify the prescriber if the pulse rate slows to 60 bpm or less Infuse the IV form slowly over at least 5 minutes</p> <p>PDE Inhibitors Typically used for short term-term management of heart failure or long term management in patients awaiting heart transplant surgery Examples: Inamrinone Milrinone Warning: - when giving PDE inhibitors (milrinone), remember that improvement of cardiac output may result in enhanced UO. Expect a dosage reduction in diuretic therapy as heart failure improves - potassium loss may predispose the patient to Digoxin toxicity</p> <p>Antianginal Reducing myocardial oxygen demand (reducing the amount of oxygen the heart needs to do its work) Or by increasing the supply of oxygen to the heart Three classes: Nitrates (acute angina) Beta-adrenergic blockers (long-term prevention of angina) Calcium channel blockers (used when other drugs fails) Nitrates Commonly prescribed: Amyl nitrite Isosorbide dinitrate Isosorbide mononitrate Nitroglycerin Assessment: Monitor VS IV nitroglycerin (monitor BP and PR q 5 to 15 minutes while adjusting the dose and every hour thereafter) Monitor the effectiveness of prescribed drugs Observe for adverse reactions</p> <p>7</p> <p>Interventions: Maybe given on empty stomach, either 30 minutes before or 1 to 2 hours after meals (tell to swallow not chew) Have the patient sit or lie down when receiving the first nitrate dose (take pulse/BP before giving the dose) Dont give beta-adrenergic blocker or calciul channel blocker to relieve a...</p>


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