Transcript Pharmacology: The Study of Drugs

Pharmacology:
The Study of Drugs
Pharmacology:
• Pharmokinetics: Study of how the body
absorbs distributes and eliminated
chemical compounds
• Pharmacodynamics: investigation of
how the drug affects the body and how
it exerts its effect
Drug Nomenclature
• Drugs can be identified according to:
– Chemical name: refers to the specific chemical
structure of the compound
– Generic name: official “nonproprietary” name
(often shorter and derived form the chemical name
– Trade Name: name assigned by the drug
manufacturer
• Several companies may make an identical
generic product but assign different names to
it (Advil, Motrin)
Drug Classifications
• Over-the-counter: The type of drugs you, yourself
may by in the drug store
– Ibuprofen, Aleve7, Aspirin etc.
• For minor problems
• Prescription: The type of drugs a Dr. must give
you a prescription for (monitored and distributed
by pharmacists, must have a license to dispense)
– Prednisone, Cortisone, Naprosen
Prescriptions
• Prescriptions are further classified
according to their potential for abuse
– called controlled substances
– Further divided into schedules I-V (V has the
lowest relative abuse potential)
– All controlled substances has laws defining
distribution
Methods of Drug Administration:
Enteral (alimentary)
• Enters body through digestive system
– Oral medication (metabolized through the liver)
– Sublingual
– rectal
Advantages of Enteral Drug
Administration
• Oral - easy
• Sublingual
– Rapid onset
– Don’t have to pass through the liver for
metabolism
• Rectal - Alternate for Oral if stomach
problems
Disadvantages for Enteral Drug
Administration
• Oral
– absorbed in the intestine - if not liquid soluble
may cause stomach pain
– absorption rate varies
– Passage through liver may nullify effects
• Sublingual: must be soluble in fatty
tissue/mucosa
• Rectal: Incomplete absorption
Drug Administration: Parenteral
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Inhalation
Injection
Topical/Transdermal application
Effects occur within 15 seconds
Drug Absorption
• Bioavailability: the extent to which
(expressed in %) the drug actually reaches
the blood stream
– Further distribution entails crossing cell
membranes, tissue barriers to the target tissue
– Greater blood flow around target tissue greater
amount of drug into target tissue.
Drug Absorption Cont.
• Passive diffusion: Drug moves from areas
of higher concentration to lower
concentration
• Lipid diffusion: ability of drug to pass
through lipid portion of cell membrane
(degree of lipid solubility will allow access
to many tissues)
Drug Absorption Cont.
• Most drugs are weak acids or bases: have
the ability to become negatively or +
charged depending on the PH of body
• Compounds must diffuse in cell junctions
(spaces between cells):
– Blood Brain Barrier: spaces may allow or
prohibit passage example capillary walls of
brain impenetrable to liquid solubles but
permeable to lipid solubles
– This is why the more lipid-soluble the drug is
the more tissues are affected
Drug Elimination
• Occurs through either: Metabolism or
Excretion
• Metabolized
– Chemically changed into compounds that are
less effective and more water soluble
– occurs primarily in the liver but also in the
lungs, kidneys, GI or skin.
– Conditions that alter these sites may alter the
elimination of the drug
Two Factors Considered in Drug
Elimination
• Drug interactions: drugs which when
metabolized stimulate or depress the
metabolism of other drugs
• Drug tolerance: drugs when used over a
prolonged period are metabolized more
rapidly than normal
Drug Half Life
• Half Life: The amount of time needed to
reduce the drug concentration to 50%
– This is important to understand how often the
drug can be administered
• 5 Half Lives - a steady state wherein the
amount administered is = to amount
eliminated
• Loading dose: first administration of the
drug is twice the normal dose to allow
concentration levels to reach effective levels
more rapidly (example prendizone)
Pharmacodynamics
• Agonist drugs: act with the receptor site to
produce an effect (drug acting to increase
the normal activity of the cell).
• Antagonist drug: acts to suppress the
activity of the cell (activity that is the cause
of discomfort or disorder)
• Efficacy: how well the drug does the above
Pharmacodynamics
• Potency: not-related to effectiveness - may
have the same effect as another drug but
requires a smaller does
• Tolerance: cells have built up a resistance
requiring increased amount of the drug to
achieve the same effects.
• Side Effects: non-desired effects of a drug
• Drug Allergy: itching, burning, skin rash or
severe reactions (anaphylactic shock)
Common Drugs in Athletic
Training
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NSAIDS
Antispasmodic
Asthma Medications
Gastrointestinal distress
Dermatologic Medications
See common drugs chart
NSAIDS
• Antipyretic: fever reducing (Asprin,
acetaminophen)
• Anti-inflammatory (ibuprofen, naproxen)
• Analgesic
• All decrease prostaglandin synthesis:
primarily responsible for causing pain
and inflammation
– Also been found to decrease
neutrophils (decrease collagen
synthesis possible weakness result),
NSAIDS: Contraindications
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Over 60 years old
History of peptic ulcers
high doses of NSAIDS or more than one
smoking
heavy alcohol consumption
Current use of corticosteroid
taking anticoagulants
NSAIDS: Salicylates
• Properties
– Analgesic, antipyretic, anti-inflammatory,
antiplatelet’
• Types
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Asprin
Choline Salicylate (Athropan)**
Magnesium Salicylate (Doan’s, Mobidin)**
Sodium Salicylate (Alka Seltzer)**
**These are methods of absorption
NSAIDS: Salicylates
• Topical Salicylates: Icy Hot, Ben Gay,
Myoflex (used to relieve pain)
• General Dose:
– 650 mg every four hours within 24 hours not to
exceed 4000mg
– loading does of 975 mg may be acceptable for
fast pain relief
– Chlorine Saliculate 435-870 mg every 4 hours
– Magnesium Salicylate 377-754 mg every 4
hours
– Sodium Salicylate 325-650 mg every 4 hours
Side Effects of Salicylates:
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Gastrointestinal
Hemtologic Effects
Nephotoxicity
Allergic reactions
Reye’s Syndrome (viral infections in
children)
• Overdose (coma, circulatory failure,
respiratory failure)
• Found to have no effects on athletic
performance
NSAIDS Non-Salicylate
• for relief of headache, myalgia,
arthralgia
• Three types
– ibuprofen (Advil7)
– Ketoprofen (Ketopron7)
– naproxen sodium (Aleve7)
CH3
O
CH3
CH3
CO2 H
CO2H
CO2 H
H3 CO
ibuprofen
ketoprofen
naproxen
NSAIDS Nonsalicylate
Generic Name
Duration RX/OTC
Diclofenac (cataflam,
voltaren)
Etodolac (lodine)
Short
RX
Short
RX
Fenoprofen (Nalfon)
Short
RX
Ibuprophen (Advil, Motrin,
Nuprin)
Idomethacin (Indocin)
Short
Rx/OTCC
Intermediate
RX
Short
RX
Flurbioprfen (Ansaid)
NSAIDS Nonsalicylate
Generic Name
Duration RX/OTC
Ketorolac (Toradol)
Short
RX
Mefenamic acid (ponstel)
Short
RX
Naproxen (Alieve, Naprosyn) Intermediate
RX/OTC
Nabumetone (Relafen)
Long
Rx
Idomethacin (Indocin)
Intermediate
RX
Piroxicam (Feldene)
Very Long
RX
Oxaprozin (Daypro)
Long
RX
NSAIDS Nonsalicylate
• General Does 200 mg tablets
• 400 mg every 4-6 hours not to exceed
1200mg
• Side Effects
– Similar to Sailcylates (no reye’s syndrome)
• Not Banned by any athletic governing
bodies
• No effect on athletic performance
Anti-inflammatory Drugs:
Corticosteroids
• Corticosteroids: steroid hormones from
adrenal cortex (may be synthetic)
• Anabolic steroids: derivations from
testosterone
• Corticosteroids: exert their influence in the
cytoplasm of affected cells, affective DNA
transcription of selected genes.
– Researchers believe the drug allows the
attraction of leukocytes into the affected area
Corticosteroids
• Indications:
Skin disorders
Nasal inflammation
Respiratory ailments
Rheumatic disorders
Chronic inflammation
Corticosteroids
• Administration
– Oral (nasal infections, respiratory ailments)
– Injection (chronic inflammation)
• Athletic Governing bodies have strict
regulations of its usage
Corticosteroids
• Side Effects
– Optic - eye pain
– Gastrointestinal
– Circulatory: lasting skin hives, discoloration,
burning itching
– Menstral irregularities
– Softening of cartilage (Delayed - over time)
Non-Anti-Inflammatory Systemic
Analgesics
• acetaminophen (Tylenol) analgesic
OTC/RX mild to moderate pain
• Opiate Agonists - for severe pain
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Morphine
Codeine
Tramadol (Ultram): for moderate to severe pain
Combination products for mild to moderate
pain (Tylenol with codeine)
Non-Anti-Inflammatory Systemic
Analgesics
• (Flexifil, Robaxin, Soma): muscle
relaxants, decrease spasm
• all cause drowsiness
• Good in combination with NSAIDS
• Side Effects
– drowsiness
– overdose
– addiction (opiates) - and/or tolerance
Asthma Medications:
• Beta 2 agonists: relax smooth muscle
– bronchiodialazters
– risk drug interactions due to protein bonds
• Corticosteroids: Inhaled or Oral
– Oral is for severe asthmatics
– adverse reactions only 10-20% reach bronchi
– Take more than 1-2 doses can cause opposite
effects
Asthma Medications:
• Cromolyn: few side effects for prevention
only
– acts by inhibition of bronchiole constriction
– beneficial for prevention, not attack
• Leukotrienes, Anti-cholinergics,
Theophyllines
– Not effective for prevention
– for severe asthmatics
– only 10-20% reach bronchi
Asthma Medications Consideration for Use
• Heart disease
• Other prescription medications
• If OTC drugs are ineffective within 1 hour
seek prescription
• Banned substances
Asthma Medication Side Effect
• Coughing after the use of any inhalers is
common
• Beta-2 agonists: “jitters” irritation
irritability, tachacardia (specifically after
repeated use), tolerance
• Orally administered Leukotrienes, Anticholinergics, Theophyllines can be
extremely toxic resulting the seizures and
cardiac arrhythmia.
• Ephedrine: may cause heart attacks seizures
and psychosis
GI Distress
• H2 blockers prevent acid secretion
(Tagamet, Zantax, Pepcid)
– May use pre-participation
– May be beneficial in preventing “stitch”
• Antacid
Dermatological
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Antifungal (topical cortizone)
Anti-virus (herpes)
Anti-bacterial (ringworm)
Anti-viral and bacterial are prescription
medications