Pharmacology Lecture Notes PDF

PHARMACOLOGY Produces no adverse effects - The study of biological effects of Can be taken conveniently, usually chemicals. by mouth Can be...

PHARMACOLOGY Produces no adverse effects - The study of biological effects of Can be taken conveniently, usually chemicals. by mouth Can be taken infrequently, usually DRUGS once a day, and for a short length of - Chemicals that are introduced into time. the body to bring about change. Is inexpensive and easily accessible Is quickly eliminate by the body after PHARMACOTHERAPEUTICS it produces beneficial effect - Branch of pharmacology that uses Does not interact with other drugs to treat, prevent or diagnose medication or food disease. MEDICATION DRUG NOMENCLATURE - Drugs used for its medicinal therapeutic effects. CHEMICAL NAME - shows the drug chemical structure. PURPOSE OF DRUGS Ex. N-(4-hydroxyphenyl) ➔ To treat ◆ Symptomatic GENERIC NAME - original designation that ◆ Cure a drug is given when the drug company that developed it, applies for approval process. ➔ To prevent ◆ To boost immune system Note: In a box and place at the top ➔ To diagnose BRAND NAME - name given to a drug by the pharmaceutical company that developed CLASSIFICATION OF DRUGS it. Note: With copyright R or ™ 1. Pharmacologic classification - Categorizes drugs based on how they exert their action in the body. EFFECTS OF DRUGS 2. Therapeutic classification - 1. THERAPEUTIC EFFECT Categorizes drugs based on their intended - Primary intended effect of the drug effect. 2. SIDE EFFECT CHARACTERISTICS OF AN IDEAL DRUG - Secondary unintended effect of the drug Effectively treats, prevents, or cures 3. ADVERSE EFFECT the client's condition. - A more severe form of side effect that may Produces a rapid, predictable justify the discontinuation of a drug. response at relatively low doses  4. ALLERGIC REACTION DRUG INTERACTIONS - An immunologic reaction of the body to the drug - DRUG TO DRUG INTERACTION ➔ Administration of one drug after the 5. ANAPHYLACTIC REACTION effects of one or both drugs - Severe allergic reaction which usually occur immediately after administration of a POTENTIATING EFFECT drug ➔ Effect of one or both are increased COMMON MILD ALLERGIC REACTIONS INHIBITING EFFECT ➔ Effect of one or both drugs are P - PRURITUS ( ITCHING) decreased R - RHINITIS A - ANGIOEDEMA W - WHEEZING (exhalation) SOURCES OF DRUGS STRIDOR (inhalation) N - NAUSEA (VOMITING) S - SKIN RASH Natural and synthetic sources of drugs PLANTS - Digitalis purpurea ( foxgloves) - Digoxin DRUG TOXICITY - Papaver somniferum ( poppy) - Morphine Belladonna atropa - Atropine Harmful effects of a drug resulting from overdose, ingestion of drugs intended for external use, or build of drug in the blood ANIMAL PRODUCTS - due to impaired metabolism or excretion. Leech - Heparin Codfish Liver - Omega 3 Pork / Cattle pancreas - Insulin DRUG TOLERANCE - INORGANIC COMPOUNDS - Aluminum - Antacid Occurence of an unusually low physiologic response to a drug, which Gold - Treatment of Rheumatoid Arthritis requires increases in the dosage to Iron - Hematopoietic maintain a given therapeutic effect. GENETIC ENGINEERING - (Recombinant Technology) E-coli - Recombinant Human insulin CUMULATIVE EFFECT - Increasing response to repeated doses of a drug which occurs when rate of administration > rate of metabolism / excretion  DRUG EVALUATION FOOD AND DRUG ADMINISTRATION PREGNANCY CATEGORIES Food and Drug Administration Category A - Adequate and Ensures the safety, efficacy or well-controlled studies have failed to quality of health products. demonstrate a risk to the fetus in the Regulatory agency under the first trimester of pregnancy Department of Health (DOH) Created under Republic Act No. Category B - Animal reproduction studies 9711 have failed to demonstrate a risk to the fetus and there are no adequate and well-controlled studies in pregnant PHASES OF DRUG DEVELOPMENT women. Category C - Animal reproduction studies PRE-CLINICAL TRIALS - Animal Testing have shown an adverse effect on the fetus and there are no adequate and PHASE 1 - Human controlled testing well-controlled studies in humans, but (healthy) potential benefits may warrant use of the drug in pregnant women despite potential PHASE 2 - Limited clinical studies ( ill individuals or sick) risks. PHASE 3 - Large scale clinical studies Category D - There is positive evidence of human fetal risk based on adverse PHASE 4 - Continual evaluation reaction data from investigational or (Monitoring for unexpected adverse effects) marketing experience or studies in humans, but potential benefits may warrant use of the drug in pregnant women despite LEGAL REGULATION OF DRUGS potential risks. Philippine law influencing drug Category X - Studies in animals or humans therapy have demonstrated fetal abnormalities and/or there is positive evidence of RA 6675 - The generics act of 1988 human fetal risk based on adverse reaction data from investigational or RA 9163 - Comprehensive dangerous drugs marketing experience, and the risks act involved in use of the drug in pregnant women clearly outweigh potential benefits. E051 - Milk code of the philippines RA 10354 - The responsible parenthood and reproductive health bill of 2012  PREGNANCY, LACTATION AND PHARMACOKINETICS REPRODUCTIVE POTENTIAL LABEL Drug movement throughout the body necessary to achieve drug action. Replace “Pregnancy Category Label” DRUG ABSORPTION - describes the Outlines risks of using a drug during drug events that happen from the time of pregnancy and lactation introduction to the time the drug reaches the Provides information on pregnancy bloodstream and tissues. testing, contraception, and infertility for female and male clients of DISINTEGRATION - The breakdown reproductive potential of an oral drug into smaller particles. DISSOLUTION - The process of combining a disintegrated solid drug with a PREGNANCY AND LACTATION liquid to form a solution. LABELING RULE EXCIPIENTS - are filler and innate substances. PREGNANCY LACTATION PASSIVE DIFFUSION - Drug movement FEMALES AND MALES OF from an area of greater concentration to REPRODUCTIVE POTENTIAL an area of lower concentration. (AMBOT SAY SUMPAY ANA GOSH) ACTIVE TRANSPORT - Drug movement which requires a carrier, such as a protein or enzymes to move the drug against a SOURCES OF DRUG INFORMATION concentration gradient. - PACKAGE INSERT ➔ PRIMARY ACTIVE TRANSPORT Contains the full prescribing information Directly uses Adenotriphosphate (ATP) to Contains the study and chemical move chemicals across a membrane. information that led to the drugs approval ECNA - Extracellular Sodium ICK - Intracellular Potassium - REFERENCE BOOKS - JOURNALS ➔ SECONDARY ACTIVE TRANSPORT - INTERNET SOURCES It uses stored energy produced during the primary active transport to provide power to cotransporter proteins. SYMPORT - occurs when two molecules are PHARMACOKINETICS - This pertains to moved by a cotransporter protein in the same how the body deals with the drugs. direction. PHARMACODYNAMICS - Studies how ANTIPORT - occurs when two molecules are the drugs affect the body. moved by a cotransporter protein in an opposite direction.;  DRUG METABOLISM - the process by PINOCYTOSIS - A process by which cells carry a drug across their membranes by which drugs are changed into new, less engulfing the drug particles in a vesicle. active chemicals. Liver is the primary site of ➔ FIRST PASS EFFECT - large metabolism. portions of medications taken orally Cytochrome P450 system - liver are deactivated by the liver and enzymes that convert drugs to never reach the target tissues. metabolites. ➔ BIOAVAILABILITY - The Lipid soluble drugs are metabolized percentage of administered drugs into a water soluble substance for available for activity. renal excretion. DRUG DISTRIBUTION - drug movement DRUG EXCRETION - removal of drugs and from the blood into the target tissues. their metabolites from the body. Drugs use proteins to circulate throughout Most drugs are excreted in the urine. the body. Kidney are the primary organ for drug excretion PLASMA PROTEINS USED FOR DRUG DISTRIBUTION URINARY EXCRETION PROCESS Albumin - most abundant protein Lipoproteins Glomerular filtration - moves drugs from Alpha 1 acid - glycoprotein (AGP) the blood to urine. Protein bound drugs are not filtered. HIGHLY PROTEIN BOUND DRUGS ➔ Drugs that are more than 90% Passive reabsorption - lipid soluble drug bound to protein. moves back into the blood. Ionized drugs WEAKLY PROTEIN BOUND DRUGS remain in the urine. ➔ Drugs that are less than 10% bound to proteins. Active transport - Tubular pumps for organic acids and bases move drugs from FREE DRUGS blood to urine. ➔ Portions of drugs that are able to exit the blood vessel and reach their site of action. OTHER SITES OF EXCRETION ★ Biles BLOOD BRAIN BARRIER ★ Breastmilk ★ a protective system of cellular ★ Saliva activity that keeps many things away ★ Sweat from CNS. ★ Exhaled air ★ Allows lipid soluble and / or low molecular weight drugs to pass through.  TIMES COURSES OF DRUG RESPONSES SINGLE DOSE TIME COURSE ➔ ONSET How long it will take to see the beginning of MULTIPLE DOSES TIME COURSE the therapeutic effect. - Administration of repeated doses results in drug accumulation until plateau (steady ➔ PEAK level) has been achieved. How long it will take to see the maximum effects of the rug. - Plateau is achieved when the amount of excretion is equal to the amount of ➔ DURATION administration. How long the patient will experience the drug effect. - Fluctuations in between doses must be kept within therapeutic range. PLASMA DRUG LEVELS PEAK CONCENTRATION - highest drug ➔ Minimum Effective Concentration level Plasma drug level below which therapeutic will not occur, beginning. TROUGH CONCENTRATION - lowest drug level ➔ Latency Percent below minimum FOR DRUGS WITH LONG / HALF LIVES ➔ Toxic Concentration Plasma drug level at which toxic effects LOADING DOSE - larger initial dose to use begin. to quickly achieve plateau. ➔ Therapeutic Range MAINTENANCE DOSE - smaller doses Plasma drug level is enough to produce a used to maintain plateau. therapeutic effect but not so much that toxicity occurs. DRUG HALF LIFE PHARMADYNAMICS Mechanism used by drugs to exert their - The time required for the amount of biochemical and physiologic effects on the drug to decrease by 50%. body. - Determines the doing intervals ( how IMPORTANCE OF much time separates each dose) PHARMACODYNAMICS Allows for comprehensive medication education to patients.  Facilitates effective clinical decision making. KEY POINTS Ensures efficiency in evaluating patients for drug effect. 1. Binding with receptors allows drugs to DOSE RESPONSE RELATIONSHIP - The either mimic or block the action of the relationship between size of an relative endogenous compound. administered dose and the intensity of response produced. 2. Drugs do not add new functions to a cell, they only alter the rate of pre existing processes. PHASES OF THE DOSE RESPONSE CURVE THEORIES OF DRUG RECEPTOR PHASE 1 - (flat curve) doses are too low THEORY to produce a response. PHASE 2 - (upward curve) dose SINGLE OCCUPANCY THEORY - The increments elicit corresponding increases intensity of response of a drug is in response. proportional to the number of receptors occupied by that drug. PHASE 3 - (flat curve) subsequent dose increments unable to elicit further A maximal response will occur when all increases in response. receptors have been occupied. DOSE RELATED DRUG PROPERTIES MODIFIED OCCUPANCY THEORY - Two ➔ Maximal efficacy - largest effect drugs can occupy the same receptor but that a drug can produce. produce effects of different intensity. ➔ Relative Potency - amount of drug needed to elicit an effect. Affinity - strength of attraction between a drug and its receptor. DRUG RECEPTOR INTERACTION ➔ Receptors are a functional Intrinsic activity - ability of a drug to macromolecule in a cell to which a activate a receptor upon binding. drug binds to produce its effects. DRUG + RECEPTOR DRUG - RECEPTOR AGONIST - are molecules that activate COMPLEX -> RESPONSE receptors. - Binding of a drug to its receptor is usually ➔ Drugs acting as agonists bind with reversible. receptors and minimize the actions - Endogenous compounds of the relative endogenous (neurotransmitters and hormones) regulate compound (dobutamine, insulin). receptor activity. - Drugs produce their effort by mimicking or PARTIAL AGONIST - are a type of agonist blocking the actions of endogenous that have moderate receptor activation compounds. power upon binding.  ➔ Drugs acting as partial agonists that can act as antagonists as well as MEDICATION USE agonists (pentazocine). PROCESS ANTAGONIST - prevents either endogenous or drug activation of receptors. PRESCRIBING - An authorized health care professional chooses the correct medication NON COMPETITIVE - bind irreversibly to and dose based on the disease. receptors reducing the total number of receptors available for activation - communicated by medication orders or (antihistamine). prescription. COMPETITIVE - produce reversible TRANSCRIBING - Accurately recording the receptor blockade by competing with prescribed medication on a medication agonists for receptor binding (naloxone). administration record. DRUG ENZYME INTERACTIONS - writing a verbal order (VO) or telephone ➔ Enzymes are biological catalysts order (TO) into the physician's order sheet. that initiate a cascade of chemical reactions in living organisms. (MAO, - VO’s and TO’s must be signed within 24 ACE, CA) hours from time in order to ensure its ➔ Drugs may exert their effects by validity. interfering with enzyme systems. ➔ Interference with any step in the DISPENSING - Pharmacist prepares, labels cascade disrupts normal cell and dispenses the final drug product based function. on the medication order or prescription. SELECTIVE TOXICITY - The ability of the - for in-patients: medication orders are drug to attack only those systems found in dispersed as unit doses. foreign cells. AT THE COMMUNITY LEVEL - A property observed in select chemotherapeutic agents. ➔ PARTIAL FILL - dispensing a lesser quantity than the amount specified in RAAS triggers hypotension, is a critical the Rx. regulator of blood volume, electrolyte ➔ REFILL - dispensing a medication balance, and systemic vascular resistance. again without requiring a new prescription. R - renin A - angiotensin ADMINISTRATION - The nurse, patient or caregiver may administer the medication. A - aldosterone S - system - the nurse must consider the 10 rights of ADMINISTRATION - medication administration in order to ensure safe and effective drug administration. ➔ Wrong patient ➔ Wrong drug - the nurse must also help the patient cope ➔ Wrong dose with the effects of drug therapy, ➔ Wrong route ➔ Wrong rate ➔ Wrong time - the nurse must ensure that the patient and or family receives all necessary drug information to ensure safe and effective BEFORE YOU GIVE IT drug therapy at home. MONITORING - patients are monitored for various drug effects. - Laboratory tests are often required for monitoring: - serum drug concentration - serum liver enzymes (ALT, AST, GGT, alkaline phosphatase) - serum creatinine - dose adjustment or regimen change may be necessary. MEDICATION ERRORS Can arise at any stage of the medication process. PRESCRIPTION ERRORS - RIGHTS OF MEDICATION ➔ Inappropriate drug choice ADMINISTRATION ➔ Calculation errors RIGHT MEDICATION ➔ Inappropriate monitoring ➔ Ascertain that the medication ➔ Therapeutic duplication given was the medication ordered. DISPENSING - 1. Retrieval ➔ Calculation problems 2. Preparation ➔ Inappropriate labeling 3. Administration ➔ Provision of inadequate information ➔ Confirmation bias in drug selection RIGHT DOSE ➔ Medication orders may include ➔ Client appropriate dose specific parameters for ➔ Know the usual dosage range of the administration. medication ➔ Conduct independent double RIGHT EVALUATION checking of critical medication ➔ Conduct appropriate follow up RIGHT TIME ➔ Administer the medication at the right frequency and at the time ordered. RIGHT ROUTE ➔ Administer the medication by the ordered route. ➔ Ensure that route is safe and appropriate for the client. RIGHT CLIENT ➔ Medication is given to the intended client ➔ Check the client’s identification band with each administration of a medication. RIGHT CLIENT EDUCATION ➔ Explain information about t6he medication to the client RIGHT DOCUMENTATION ➔ Document medication administration after giving it, not before. RIGHT TO REFUSE ➔ Adult clients have the right to refuse ➔ Nurses' role is to inform clients of potential consequences of refusal and communicate refusals to healthcare providers. RIGHT ASSESSMENT ➔ Some medications require specific assessment prior to administration.