Transcript PowerPoint Presentation - Slide 1

Pharmacology
Dr. Lou Fincher, ATC, LAT
Associate Professor & Associate Chair
Director, Athletic Training Education Program
The University of Texas at Arlington
Learning Outcomes
Review the cognitive competencies
from the Pharmacology Domain
Competencies in Athletic
Training
1. Explain the laws, regulations, and
procedures that govern storing,
transporting, dispensing, and recording
prescription and nonprescription
medications (Controlled Substance Act,
scheduled drug classification, and state
statutes).
Managing Medications
 http://www.nata.org/stateme
nts/consensus/ConsensusSt
atementManagingMedicatio
n.pdf
Drug Classification
Over-the-counter (OTC)
Prescription (Rx)
Controlled substances (scheduled)
Drug Classification
Controlled Substances
• Greater potential for abuse than prescription
drugs
• Greater restriction in storage, distribution, and
record keeping
Drug Classification
Controlled Substances
• Schedule I
– highest potential for abuse
• Schedule II
• Schedule III
• Schedule IV
– lowest potential for abuse
• Schedule V
Drug Classification
Controlled substances
• most narcotic pain prescriptions are classified
as Schedule III
• anabolic steroids are also Schedule III
Competencies in Athletic
Training
2. Identify appropriate pharmaceutical
terminology and abbreviations used in the
prescription, administration, and
dispensing of medications.
Terminology & Abbreviations
Abbreviations for dosage
• qd – every day
• bid – twice a day
• tid – three times a day
• qid – four times a day
• q 3 h – every 3 hours
Competencies in Athletic Training
3. Identify information about the indications,
contraindications, precautions, and
adverse reactions for common
prescription and nonprescription
medications (including herbal
medications) using current pharmacy
resources
Common OTC and Rx Meds
Treatment of musculoskeletal disorders
• NSAIDs
• corticosteroids
• analgesics
Common OTC and Rx Meds
Treatment of infections
• antibiotics
• antifungals
• antivirals
Common OTC and Rx Meds
Management of asthma
• short acting β2-agonists
• long acting β2-agonists
• corticosteroids
• leukotriene modifiers
• cromones
Common OTC and Rx Meds
Treatment of GI disorders
•
•
•
•
antigas
antacids
antidiarrheals
antiemetics
Common OTC and Rx Meds
Treatment of colds & allergies
•
•
•
•
antihistamines
decongestants
antitussives
expectorants
Common OTC and Rx Meds
Herbal supplements
•
•
•
•
•
St. John’s Wort
gingko
ginseng
garlic
echinacea
Competencies in Athletic Training
4. Explain the concepts of pharmacokinetics
and the suspected influence that exercise
might have on these processes.
Pharmacokinetics
How the body handles a drug
Four phases (ADME process)
• absorption
• distribution
• metabolism
• elimination
Absorption
For a drug to produce a therapeutic effect,
it must be absorbed into the bloodstream
and distributed through the circulation
Absorption
Absorption requires the drug molecule to
move across a membrane
• simple diffusion
• active transport
• facilitated diffusion
Absorption
Oral absorption
• drugs taken by mouth pass to the stomach &
then the intestine
• they are absorbed from the GI tract into the
circulatory system
• the quicker the drug dissolves, the quicker it
can be absorbed
Absorption
First pass effect
• some drugs will pass through the liver before
being distributed throughout the blood stream
• when these drugs pass through the liver, they
are broken down (metabolized) into inactive,
less active, or more active compounds
Absorption
Absorption is also affected by solubility of
drug
• lipid soluble drugs can easily pass through
the blood-brain barrier to affect the CNS
• water soluble drugs are more easily and
quickly excreted
Absorption
Oral absorption
• almost all drug absorption takes place in the
small intestine
• most drugs recommend that they be taken
with a full glass of water
 this liquid helps move the drug more quickly into
the intestines
 food in the stomach delays the absorption of a
drug
Absorption
Oral absorption
• gastric emptying can occur in as little
 10 minutes on empty stomach
 Hours on a full stomach (large meal)
• some foods can interfere with drug absorption
 Dairy products & tetracyclines (antibiotic)
Absorption
Oral absorption
• some drugs are designed for delayed
absorption
 extended release
 controlled release
• these drugs usually contain a larger dosage to
account for the delayed time in absorption
Absorption
Oral absorption
• delayed absorption
 many extended release drugs contain an enteric
coating
– doesn’t dissolve until it reaches the small intestine
Absorption
Oral absorption
• Extended release drugs SHOULD NOT be
cut, crushed, or broken in half
Absorption
Exercise decreases absorption of drugs
taken by mouth
• blood is diverted away from the GI tract to the
skeletal muscles
• when the body absorbs less of a drug, its
therapeutic effectiveness is decreased
Absorption
Sublingual & buccal
• dissolve directly in the mouth
• rapid absorption due to rich blood supply in
the mouth
• provide a rapid therapeutic effect
• eliminates the first pass effect
• nitroglycerin provides a peak response in 3-5
minutes
Absorption
Rectal
• drug dissolves in the rectum and is absorbed
into the bloodstream by the hemorrhoidal
veins
 advantages of rectal administration
– good for those suffering from nausea & vomiting
 disadvantages of rectal administration
– absorption varies & is often incomplete
Absorption
Intravenous
• no true absorption – they are injected directly
into bloodstream
Intramuscular
• faster absorption than subcutaneous
Subcutaneous faster than oral
Absorption
Topical
• slow absorption – drug must pass through the
skin
Inhalation
• rapid absorption (<5 min.)
Distribution
Once absorbed into the bloodstream, the drug
can be distributed to target sites throughout the
body
Exercise increases the distribution of most drugs
• increasing cardiac output increases the speed at
which the circulatory system carries the drug to its
target site
Distribution
Affected by a drug’s lipid solubility
• drugs with high lipid solubility can easily
penetrate fat stores and cross membrane
barriers → providing a broader distribution
• water soluble drugs can be easily eliminated
from the body
• fat soluble drugs can be stored in the body,
providing longer lasting effects
Distribution
Onset of action
• time it takes for the
drug to reach a
concentration level
large enough to
cause a noticeable
biological effect
Distribution
Duration of action
• the length of time
the drug produces
a therapeutic
effect
Distribution
A drug’s most intense effects occur during
the peak serum concentration
• when the highest level of the drug is in the
bloodstream
Metabolism
Clearing process that breaks down
substances into water soluble form for
easy excretion
• primary site → liver
• may also occur in the kidneys, GI tract, and
lungs.
Metabolism
Exercise can decrease the clearance of
some drugs due to blood being diverted
away from the GI, kidneys, and liver to the
working skeletal muscle
Metabolism
HOWEVER, since the duration
of the drug’s effects is usually longer than
an exercise session, the overall effect of
exercise on drug metabolism is
insignificant or negligible.
Elimination or Excretion
Removal of the drug from the body
• primary method
 kidneys → urine
• other methods
 Biliary tract → feces
 Lungs → respiration
 Sweat glands → perspiration
Elimination or Excretion
Exercise can slow the rate of excretion
since blood flow will be diverted away from
the kidneys to the working skeletal muscle
Excretion rate also affected by the drug’s
half-life
Competencies in Athletic Training
5. Explain the concepts related to
bioavailability, half-life, and
bioequivalence.
Bioavailability
The amount of drug actual active in the
body tissues
Typically just a fraction of its dosage size
Bioavailability
If a drug’s bioavailability is 50%, then the
body will only absorb 250 mg of a 500 mg
dose.
• Naproxen (Naprosyn) – bioavailability is 95%
• Voltaren – bioavailability is 50-60%
Bioavailability
Bioavailability is affected by
• rate at which a drug dissolves in the GI tract
• amount and rate of drug absorbed
• formulation
 capsule, tablet, injection, oral, etc.
• first pass effect (liver)
Half-Life
The time required for the body to eliminate
one-half of a dosage of a drug by regular
physical processes
• if a drug has a half-life of 8 hours, then it will
take 8 hours for the blood concentration of the
drug to be decreased by 50%
Half-Life
Naproxen (Naprosyn) has a half-life of 12 -17
hours
• it will take 12 hours to reduce the blood concentration
of a 500 mg dose to 250 mg
Water
• soluble drugs will have shorter half-life than lipid
soluble drugs
Lipid soluble drugs
• will remain in the system longer.
Competencies in Athletic Training
6. Explain the general pharmacodynamic
principles as they relate to the
mechanism of drug action and
therapeutic effectiveness
a. receptor theory
b. dose-response relationship
c. potency
d. drug interactions
Pharmacodynamics
For drugs to work, they must bind with a
receptor
• The receptor can be a molecule within a cell
or on the cell membrane
Once the drug binds to the
receptor, it initiates a
transduction response
(movement of the drug into
the cell)
Pharmacodynamics
Receptors exist so that a biological
response can be regulated through an
endogenous compound
• initiates response
• blocks response
Pharmacodynamics
Drugs that bind to receptors are either
mimicking (agonist) or blocking
(antagonist) the response of endogenous
compounds
Pharmacodynamics
Relationship between a drug and receptor
is much like a lock and key
• very specific fit
• any chemical change in the drug or the
receptor can change the interaction
Pharmacodynamics
Drug dosing
• based on the
 drug’s potency
 patient’s age
 patient’s condition
• the larger the dose, the more receptors will be
occupied
 this occurs up to a point (steady state
concentration)
Pharmacodynamics
Potency
• strength of drug
• the greater the potency, the smaller the dose
necessary to produce therapeutic effect
Examples of Drug Dosing
Aspirin
• usually manufactured in 325 mg tablets
• typical dose = 2 tablets (650 mg) every four
hours
Ibuprofen
• typical dose = 400 mg.
Ketoprofen (Orudis)
• typical dose 12.5 mg every four to six hours
Drug Interactions
Occur when one drug alters the effect of
another drug
May change how the body handles one or
both of the drugs:
• antacids reduce the body’s ability to absorb
acetaminophen from the intestine
• some antibiotics may accelerate the
metabolism of oral contraceptives
May change the way a drug acts on the
body
Drug Interactions
Can be additive or inhibitive
• additive effects occur when someone takes
two drugs of the same type at the same time
 example: two stimulants or two depressants
• the effects of the drugs “add together”
Drug Interactions
Additive effects (agonistic)
• a diet pill (appetite suppressant – which is a
stimulant) combined with several cups of
coffee (also a stimulant) may cause heart
palpitations, tachycardia, insomnia
• alcohol combined with an antihistamine (both
are depressants) may cause excessive
drowsiness, dizziness, loss of muscle
coordination, and loss of mental alertness
Drug Interactions
Can easily occur through innocent use of
OTC meds
• particularly with combination products for the
treatment of colds and allergies
• caution your athletes to read the labels of
OTC meds
Inhibitory effects may occur with the
combination of two unrelated drugs
Drug Interactions
Inhibitory effects (antagonistic)
• some antibiotics may inhibit or reduce the
effectiveness of oral contraceptives
• aspirin may increase the effects of insulin
• dairy products may reduce the effectiveness
of tetracycline (an antibiotic)
Adverse Drug Reactions
Range from a side-effect to
hypersensitivity
• examples of side effects (predictable):
 drowsiness produced by an antihistamine
 loss of appetite associated with many antibiotics
• examples of hypersensitivity:
 allergic reactions that range from a simple rash to
bronchial spasm or anaphylactic shock
Adverse Drug Reactions
Can occur immediately or be delayed
• most delayed effects occur with chronic use of
a drug
 chronic use of Tylenol is linked to liver damage
 alcohol ingested with aspirin or other NSAIDs may
cause GI bleeding
 chronic alcohol consumption and acetaminophen
can cause liver damage
Competencies in Athletic Training
7. Describe the common routes used to
administer medications (e.g., oral,
inhalation, and injection) and their
advantages and disadvantages.
Routes of Drug Administration
Enteral
• enters the body by way of the alimentary
canal or digestive system
Parenteral (nonenteral)
• pathway other than through the alimentary
canal or digestive system
• usually allows drug to be delivered directly to
target tissue
Routes of Drug Administration
Enteral
• oral
• rectal
Parenteral
• inhalation
• injection
• topical or transdermal application
• sublingual
Routes of Drug Administration
Systemic effects
• oral
• injection (either intramuscular, intravenous,
•
•
•
•
•
subcutaneous, or intra-articular)
intranasal
oral inhalation
sublingual (under the tongue)
buccul (inside the cheek or directly on the
gum)
rectal
Routes of Drug Administration
Local effects
• ophthalmic (eye)
• otic (ear)
• topical (skin)
Routes of Drug Administration
Most immediate effects produced by:
• intravenous
• inhalation (oral or nasal)
• sublingual absorption
Drugs administered orally may require 30
minutes before relief is provided
Liquids or powders dissolved in water will
act more quickly than tablets or capsules
Competencies in Athletic Training
8. Explain the relationship between generic
or brand name pharmaceuticals.
Drug Nomenclature
Drugs are identified by one of 3 names
• Chemical – long name, refers to the chemical
structure of the drug
• Generic – shorter name derived from the
chemical name [nonproprietary]
• Trade – brand name assigned by the
manufacturer [proprietary]
Drug Nomenclature
Generic Name
Trade Name
Pseudoephedrine
Actifed, Sudafed
Erythromycin
E-Mycin, Erythrocin
Cephalosporin
Keflex, Keflin, Suprax, Utrace
Penicillin
V-Cillin, Amoxil
Acetomenophin
Tylenol
Naproxen Sodium
Aleve
Ibuprofen
Motrin, Advil
There is only one generic name for each drug, but there may be multiple
trade names if the drug is marketed by more than one company.
Drug Nomenclature
Generic “name” ≠ generic “drug”
• every drug has a generic name
• not every drug is available in a generic
form
 currently, about half the drugs on the market
are available in generic form
Drug Nomenclature
What is a generic drug?
• a copy of a brand-name drug whose patent has
expired
• during a patent period (20 years), only the original
manufacturer can market the patented drug
• after the patent expires, any company can market the
drug – usually marketed under the generic “name”
Drug Nomenclature
What’s the difference between a generic
drug and a brand-name drug?
• cost $$$
• brand-name drugs may cost up to 4 times
more than a generic drug
Drug Nomenclature
Standard practice and most state laws
require that a generic drug be generically
equivalent to its brand-name counterpart.
• same active ingredients, strength, and
dosage form—pill, liquid, or injection
• must be therapeutically equivalent—it must
be the same chemically and have the same
medical effect
Competencies in Athletic Training
9. Identify medications that might cause
possible poisoning, and describe how to
activate and follow the locally established
poison control protocols.
Online Resources
American Association of Poison Control Centers
http://www.aapcc.org/
National Capital Poison Center www.poison.org
Competencies in Athletic Training
10.Explain the known usage patterns,
general effects, and short- and long-term
adverse effects for the commonly used
performance enhancing substances.
Performance Enhancing Drugs
Androgenic anabolic steroids
Human growth hormone
Erythropoietin
Creatine (supplement)
Steroid precursors
• androstenedione ("andro")
• dehydroepiandrosterone (DHEA)
Competencies in Athletic Training
11.Identify which therapeutic drugs and nontherapeutic substances are banned by
sport and/or workplace organizations in
order to properly advise patients about
possible disqualification and other
consequences.
Online Resources
NCAA Banned Drug List
http://www.ncaa.org/sports_sciences/drugtesting
/banned_list.html
United States Olympic Committee Drug Policies
http://usoc.org/inside/drugadmin.html
United State Antidoping Agency
http://www.usantidoping.org
Drug Resources
It would be virtually impossible for athletic
trainers to be familiar with every drug that might
be used to treat the injuries or illnesses of their
patients
Print and online drug resources can be used to
quickly obtain information about a
An Athletic Trainer would be wise to seek out a
local pharmacist that is willing to serve as a
resource for questions regarding medications.
Online Resources
 Drug Information Online: http://www.drugs.com
 RxList: www.rxlist.com
 Healthsquare:
www.healthsquare.com/drugmain.htm
 Healthtouch:
www.healthtouch.com/level1/p_dri.htm
 WebMD:
http://www.webmd.com/medical_information/dru
g_and_herb/default.htm
 FDA: www.fda.gov/cder/drug/default.htm
Online Resources
 American Association of Poison Control Centers
http://www.aapcc.org/
 National Capital Poison Center www.poison.org
 NCAA Banned Drug List
http://www.ncaa.org/sports_sciences/drugtesting/banned
_list.html
 United States Olympic Committee Drug Policies
http://usoc.org/inside/drugadmin.html
 United State Antidoping Agency
http://www.usantidoping.org
 Food and Drug Administration Recalls and Safety Alerts
http://www.fda.gov
Print Resources
 AHFS Drug Handbook. American Society of Health-System
Pharmacists: Bethesda, MD and Lippincott Williams & Wilkins:
Springhouse, PA.
 Drug Facts and Comparisons. St. Louis, MO: Facts and
Comparison.
 Physician’s Desk Reference. Montvale, NJ: Medical Economics
Company, Inc.
 PDR for Nutritional Supplements. Montvale, NJ: Thomson PDR
 PDR for Herbal Supplements. Montvale, NJ: Thompson PDR
 PDR for Nonprescription Drugs and Dietary Supplements. Montvale,
NJ: Thompson PDR
Questions?
Thank You!