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Pharmacology. Lisa H. Young, RN, BSN, MA Ed. Daymar College. Classifications and Prototype Drugs ( Pr ) Intravenous Drug Administration Adverse Effects Diagnostic Test Interference Interactions Pharmacokinetics Clinical Implications Therapeutic Effectiveness Pregnancy Category.
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Pharmacology Lisa H. Young, RN, BSN, MA Ed. Daymar College
Classifications and Prototype Drugs (Pr) Intravenous Drug Administration • Adverse Effects • Diagnostic Test Interference • Interactions • Pharmacokinetics • Clinical Implications • Therapeutic Effectiveness • Pregnancy Category • Controlled Substances • Availability • Uses and Unlabeled Uses • Action and Therapeutic Effect • Contraindications and Cautious Use • Route and Dosage • Administration http://www.youtube.com/watch?v=Jh_U8V9-Htw http://www.youtube.com/watch?v=9mcqPJFB3UE How to use drug book
Pharmacodynamics • The study of the action of drugs on living tissue • Pharmacokinetics • The study of the processes of drug absorption, distribution, metabolism, and excretion • Pharmacotherapeutics • The study of the use of drugs in treating disease • Pharmacy • The science of preparing and dispensing medicines Major areas of pharmacology
Posology • The study of the amount of drug that is required to produce therapeutic effects • Toxicology • The study of the harmful effects of drugs on living tissue
Drugs come in various dosage forms: • The physical and chemical properties of a drug usually determine what form will be most effective. • Some common dosage forms include tablets, capsules, syrups, and injectables. Drug forms
Drugs have three different names: • Chemical • Generic • Brand or Trade • Drugs are also divided into the following classifications: • Prescription • Nonprescription (OTC) Drug nomenclature
Drugs can enter the body several different ways. Two common routes are orally and parenterally. Routes of administration
There are four pharmacokinetic phases: • Absorption • Distribution • Metabolism • Excretion Pharmacokinetic phases http://connect.mheducation.com/connect/hmEBook.do?setTab=sectionTabs
Half-life • Half-life is the amount of time it takes for the blood concentration to drop by half of the original amount. • Blood drug levels • The intensity of a drug effect is determined mainly by the concentration of drug in the blood. Half-life & blood drug levels
Bioavailability is the percentage of drug that is actually absorbed into the bloodstream. There are several factors that influence bioavailability. bioavailability
Drug interaction refers to one drug affecting the actions of another drug. • There are several types of drug interactions: • Incompatibility • Additive Effects • Summation • Synergism • Antagonism Drug interactions
Tolerance • Dependence • Decreased drug effect with repeated administration • Two main types are metabolic and pharmacodynamic. • Reliance on drug becomes ever more vital to the well-being of the patient • The two types are physical and psychological. Chronic drug use & abuse
Prescription Orders • Patient Name (superscription) • Address • Drug name (inscription) • Drug dose • Route (subscription) • Frequency of administration • Number to be dispensed • Number of refills allowed • DEA # • MD Name/signature • MD address • MD Phone number http://www.youtube.com/watch?v=Mhqe12Aj1dE Pharmacologic principles
http://www.youtube.com/watch?v=S0oqYJp9t2o http://www.youtube.com/watch?v=hRdGLzylovM Reading prescription labels
Ten Rights • Right patient name • Right drug • Right dosage • Right route & technique • Right time • Right documentation • Right client education • Right to refuse • Right assessment • Right evaluation http://www.youtube.com/watch?v=cm7GexPKNOc&list=PLxdOP8vuQhz9SNJLTWjTGzh3yOTsEsd6l http://www.youtube.com/watch?v=yhHq-pV6HOw Medication administration
With an aging population comes an increase in geriatric prescriptions. • It is not uncommon for some elderly patients to have 3 or more prescriptions. • Aging affects all four phases of pharmacokinetics. • As one ages, the following changes alter drug absorption: • Decrease in the blood flow to the intestines • Decrease in gastric acid secretions • As one ages, the following changes alter drug distribution: • Decrease in lean body mass • Decrease in total body water • Increase in body fat Drug use in the elderly
Altered drug metabolism • Decrease blood flow to liver • Decrease production of metabolizing enzymes • Increased drug duration of action • Altered drug excretion • Decrease in blood flow to kidneys • Decrease in all areas of renal function • Increased blood plasma concentrations • Need for reduced dosages Drug use in the elderly
Several factors associated with aging affect drug response: • Nutritional status • Disease states • Changes in pharmacodynamicresponses Effects of age on drug response
Elderly patients can be confused about their medications. • They may need a change in dosage form to allow for easier administration. • Polypharmacy is a concern as well. Drug compliance in the elderly
Website addresses for current immunization schedules • American Academy of Pediatrics • http://www.aap.org • American Academy of Family Physicians • http://www.aafp.org • American College of Obstetricians and Gynecologists • http;//www.acopg.org • Advisory Committee on Immunization Practices • http://www.cdc.gov/vaccinesacip Immunization Schedule
A ratio is the relationship of one number to another number: 2:7 or 2/7 • A proportion expresses the equality between two ratios 3:4 = 12:16 Dosage calculations
There are different measuring systems used in pharmaceutical calculations and dosages: • Metric • Apothecary • Household Systems of measurement
gr = grain gal = gallon dr = dram qtiii = 3 quarts oz = ounce ix = 9 lb = pound qti = 1 quart m = minims gr ½ = ½ grain fldr = fluid drams ptiiiss = 3 ½ pints floz = fluid ounce 1 grain = 60 mg pt = pint qt - quart Apothecary System
Dosage unit • Dosage strength • Dosage ordered • Desired dose • Dose on hand • Amount to administer Dosage definitions
Metric Conversion Value Chart Kilo – Hecto-Deka-Base-Deci-Centi-Milli-X-X-Micro Gram Liter Meter 45.2 grams = 45200.0 milligrams 1cubic centimeter (cc) = 1 milliliters (ml) Dosage Calculations http://www.youtube.com/watch?v=2QR9yCkAEpE
Drug Calculation: Formula Method Ordered Dose X Available Amount Available Dose Amount to give Ordered dose: 500 mg Available dose: 1000 mg Available amount: 1 ml 500 mg X 1 ml = 0.5 or ½ ml 1000mg ? Dosage Calculations http://www.youtube.com/watch?v=b69Wr008dzM http://www.youtube.com/watch?v=BMDOk3RAHC4 http://www.youtube.com/watch?v=Wa9Zi64_HJk
Rounding 1.75 to the nearest tenth. If the number in question is 5 or greater, add 1 to the last number, and drop all the numbers to the right of the changed number. 1.75 → 1.8 If the number in question is less than 5, do not change the last number, but drop all the numbers to the right of that number 1.74 → 1.7 Rounding Medication Dosages
Divide the weight by 2.2 = weight in kilograms • 32 pounds / 2.2 = 14.5454545kg • Round answers to the nearest hundredth • 14.5454 = 14.55 kg • Weight in pounds and ounces, convert ounces to a decimal before dividing by 2.2 • 14 pounds and 6 ounces = 14.50 pounds • Divide 4 by 16 = 0.50 Pounds to Kilograms
1. Convert weight in pounds into kilograms 20 lbs / 2.2 = 9.09 kilograms or 9 kilograms 2. Multiply the amount of medication (mg) by the kilograms Example: 20 lb child Give 5 mg/kg of medication. calculation: 5mg X 9 kg = 45 mg of medication Available dose: 100mg/ml 45 mg/100mg X 1ml/?ml = 0.45 ml = 0.46 ml Body Weight Method Dosage Calculation http://www.youtube.com/watch?v=AQaeAON4GUM
Single-Dosage Drugs Intended to be given once or p.r.n. Multiply the recommended mg by the patient’s kg weight for each dose. Calculate one dose: ordered dose/available doseX dose unit Single-Dosage-Range-Drugs Single-dosage medications indicate a minimum and maximum range or a safe dosage range. Pediatric Dosage Calculations
Routine or Round-the-clock Drugs Dosages intended to produce a continuous effect on the body over 24 hours. Total daily dose then divided by ordered divided doses Daily-Dosage-Range Drugs Many medications are recommended by a minimum and maximum mg/kg range per day, to be divided into some number of doses. Pediatric Dosage Calculations
ac before meals alt. h. alternate hours bid twice a day fl. fluid HS at bedtime caps capsule PRN whenever this is needed dil. dilute Q2h every 2 hours gtt drop Q4h every 4 hours inj injection Q6h every 6 hours kg kilogram Q8h every 8 hours L liter TID three times daily liq. liquid QID four times daily noct. night STAT give immediately R or PR rectally/per rectum Ad lib as desired c with H hour s without pc after meals tab tablet po oral tsp. teaspoon IM intramuscular ung ointment Pharmacology Abbreviations
Procanbid500 mg p.o.b.i.d. Give 500mg of Procanbid orally twice daily. Phenytoin 100mg p.o.t.i.d. Give 100mg of Phenytoin orally three times daily Reading & Interpreting orders
Six Cs of Charting • Client’s own words • Clarity • Completeness • Conciseness • Chronological • Confidentiality http://www.youtube.com/watch?v=mYGf0AdhhI4 http://www.youtube.com/watch?v=SDcmXqSvP7A Charting medication administration
Date/time of entry • Legible handwriting • Permanent black ink • Proper terminology, correct spelling and correct grammar • Document in sequence • Be concise • Correct errors • Sign every entry http://www.youtube.com/watch?v=pe2TQJKXZIs http://www.youtube.com/watch?v=GMVwoR0YU-I http://www.youtube.com/watch?v=Bkoic2dLFmY Guidelines for Charting
9/1/12 9:00 a.m. nitroglycerin, 1 tab, sublingually. Written instructions given to pt. Precautions explained. Told to call office at 1:00p.m. today to report progress of his condition….M. Richards, CMA (AAMA) • 1/19/12 11:00 a.m. B 12 vitamin, 10000mcg given IM to left deltoid muscle without complications and band aid applied to injection site. Pt tolerated injection well. Pt. given written instructions for possible side effects and considerations. Pt to return in one monthly to receive monthly B 12 injections as ordered……L.Young, CCT. • 10/10/2012 1:00 p.m. Mantoux test, 0.01 ml. Tuberculin Purified Protein Derivative, Left forearm, subcutaneous, small wheal noted. Pt. instructed not to rub or cover the are and to return for reading on 10/12/12…..M. Richards, CMA (AAMA) Charting examples
Assessment • Plan • Implementing • Document • Evaluate • Special Needs • Noncompliance Patient education http://www.youtube.com/watch?v=1HQHdpAov-I
Cultural Considerations • The Life Span • In the Workplace • The Law • Understanding and knowledgeable about medication professionalism
Antiinflammatory Drug Action Nonopioids NSAIDs Salicylates Drug Interactions Preferred Therapy Acetaminophen Nonopioid Analgesics, Nonsteroidal Antiinflammatories, and Antigout Drugs