PHARMACOLOGYLisa H. Young, RN, BSN, MA Ed.

Daymar College

HOW TO USE DRUG BOOK

http://www.youtube.com/watch?v=Jh_U8V9-Htw

http://www.youtube.com/watch?v=9mcqPJFB3UE

Controlled Substances Availability Uses and Unlabeled Uses Action and Therapeutic Effect Contraindications and Cautious

Use Route and Dosage Administration

Classifications and Prototype Drugs (Pr) Intravenous Drug Administration

Adverse Effects Diagnostic Test Interference Interactions Pharmacokinetics Clinical Implications Therapeutic Effectiveness Pregnancy Category

• PharmacodynamicsThe 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

DRUG FORMS

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.

• Therapeutic Effect

Desired Effects

• Side Effect• Adverse

Effect• Toxic Effect

Undesired

Effects

DRUG EFFECTS

DRUG NOMENCLATURE

• Drugs have three different names:ChemicalGenericBrand or Trade

• Drugs are also divided into the following classifications:

PrescriptionNonprescription (OTC)

ROUTES OF ADMINISTRATION

Drugs can enter the body several different ways.

Two common routes are orally and parenterally.

PHARMACOKINETIC PHASES

There are four pharmacokinetic phases: Absorption Distribution Metabolism Excretion

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HALF-LIFE & BLOOD DRUG LEVELS

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 levelsThe intensity of a drug effect is determined mainly by the concentration of drug in the blood.

BIOAVAILABILITY

Bioavailability is the percentage of drug that is actually absorbed into the bloodstream.

There are several factors that influence bioavailability.

DRUG INTERACTIONS

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

CHRONIC DRUG USE & ABUSE

Tolerance Decreased drug

effect with repeated administration

Two main types are metabolic and pharmacodynamic.

Dependence Reliance on drug

becomes ever more vital to the well-being of the patient

The two types are physical and psychological.

PHARMACOLOGIC PRINCIPLES

Prescription OrdersPatient Name (superscription)AddressDrug name (inscription)Drug doseRoute (subscription)Frequency of administrationNumber to be dispensedNumber of refills allowedDEA #MD Name/signatureMD addressMD Phone number

http://www.youtube.com/watch?v=Mhqe12Aj1dE

READING PRESCRIPTION LABELS

http://www.youtube.com/watch?v=S0oqYJp9t2ohttp://www.youtube.com/watch?v=hRdGLzylovM

MEDICATION ADMINISTRATION

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

DRUG USE IN THE ELDERLY

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 intestinesDecrease in gastric acid secretions

As one ages, the following changes alter drug distribution:Decrease in lean body massDecrease in total body waterIncrease 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

EFFECTS OF AGE ON DRUG RESPONSE

Several factors associated with aging affect drug response:

Nutritional statusDisease statesChanges in pharmacodynamic responses

DRUG COMPLIANCE IN THE ELDERLY

• 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.

IMMUNIZATION SCHEDULE

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

DOSAGE CALCULATIONS

A ratio is the relationship of one number to another number:

2:7 or 2/7A proportion expresses the equality between two ratios

3:4 = 12:16

SYSTEMS OF MEASUREMENT

There are different measuring systems used in pharmaceutical calculations and dosages:

Metric Apothecary Household

APOTHECARY SYSTEM

gr = grain gal = gallondr = dram qt iii = 3 quartsoz = ounce ix = 9lb = pound qt i = 1 quartm = minims gr ½ = ½ grainfl dr = fluid drams pt iiiss = 3 ½ pintsfl oz = fluid ounce 1 grain = 60 mgpt = pintqt - quart

RULES OF CONVERSION

Apothecary Metric

1 fluid oz 30 mL or cc

1 quart 1000 mL or cc

1 grain 0.065 gram

15 grains 1 gram

2.2 pounds 1 kilogram

Household Metric

1 drop 0.06 mL

1 tsp 4-5 mL

1 T 15-16 mL

1 cup 250 mL

2 cups 500 mL

DOSAGE DEFINITIONS

• Dosage unit

• Dosage strength

• Dosage ordered

• Desired dose

• Dose on hand Amount to administer

DOSAGE CALCULATIONS

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)

http://www.youtube.com/watch?v=2QR9yCkAEpE

DOSAGE CALCULATIONS

Drug Calculation: Formula Method

Ordered Dose X Available Amount

Available Dose Amount to give

Ordered dose: 500 mgAvailable dose: 1000 mgAvailable amount: 1 ml

500 mg X 1 ml = 0.5 or ½ ml 1000mg ?

http://www.youtube.com/watch?v=b69Wr008dzMhttp://www.youtube.com/watch?v=BMDOk3RAHC4http://www.youtube.com/watch?v=Wa9Zi64_HJk

ROUNDING MEDICATION DOSAGES

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

POUNDS TO KILOGRAMS

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

BODY WEIGHT METHOD DOSAGE CALCULATION

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 medicationAvailable dose: 100mg/ml45 mg/100mg X 1ml/?ml = 0.45 ml = 0.46 ml

http://www.youtube.com/watch?v=AQaeAON4GUM

PEDIATRIC DOSAGE CALCULATIONS

Single-Dosage DrugsIntended 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-DrugsSingle-dosage medications indicate a minimum and maximum range or a safe dosage range.

PEDIATRIC DOSAGE CALCULATIONS

Routine or Round-the-clock DrugsDosages intended to produce a continuous effect on the

body over 24 hours.

Total daily dose then divided by ordered divided doses

Daily-Dosage-Range DrugsMany medications are recommended by a minimum and

maximum mg/kg range per day, to be divided into some number of doses.

PHARMACOLOGY ABBREVIATIONS

ac before meals alt. h.alternate hours

bid twice a day fl.fluid

HS at bedtimecaps capsulePRN whenever this is needed dil.

diluteQ2h every 2 hours gtt

dropQ4h every 4 hours inj

injectionQ6h every 6 hours kg

kilogramQ8h every 8 hours L

literTID three times daily liq.

liquidQID four times daily noct.

nightSTAT give immediately R or PRrectally/per rectumAd lib as desired c

withH hour s

withoutpc after meals tab

tabletpo oral

tsp. teaspoonIM intramuscular ung

ointment

READING & INTERPRETING ORDERS

Procanbid 500 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

CHARTING MEDICATION ADMINISTRATION

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

GUIDELINES FOR CHARTING

• 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=pe2TQJKXZIshttp://www.youtube.com/watch?v=GMVwoR0YU-Ihttp://www.youtube.com/watch?v=Bkoic2dLFmY

CHARTING EXAMPLES

A. 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)

B. 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.

C. 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)

PATIENT EDUCATION

• Assessment• Plan• Implementing• Document• Evaluate• Special Needs• Noncompliance

http://www.youtube.com/watch?v=1HQHdpAov-I

PROFESSIONALISM

• Cultural Considerations

• The Life Span

• In the Workplace

• The Law

• Understanding and knowledgeable about medication

Skeletal Muscle Relaxants

OPIOID ANALGESICS

NONOPIOID ANALGESICS, NONSTEROIDAL ANTIINFLAMMATORIES, AND ANTIGOUT DRUGS

Antiinflammatory Drug Action

Nonopioids

Salicylates

Acetaminophen

NSAIDs

Drug Interactions

Preferred Therapy

ANTIANGINAL DRUGS

DIURETICS

ANTIHYPERTENSIVE DRUGS

NUTRITION AND THERAPY

RESPIRATORY PHARMACOLOGY

THERAPY OF GASTROINTESTINAL DISORDERS

ANTIBACTERIAL AGENTS

ANTISEPTICS & DISINFECTANTS

IMMUNOPHARMACOLOGY