Pharmacology: The Study of Drugs

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Pharmacology The Study of Drugs
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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

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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)

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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

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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

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Methods of Drug Administration Enteral
(alimentary)

• Enters body through digestive system
• Oral medication (metabolized through the liver)
• Sublingual
• rectal

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Advantages of Enteral Drug Administration

• Oral - easy
• Sublingual
• Rapid onset
• Dont have to pass through the liver for
  metabolism
• Rectal - Alternate for Oral if stomach problems

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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

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Drug Administration Parenteral

• Inhalation
• Injection
• Topical/Transdermal application
• Effects occur within 15 seconds

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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.

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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)

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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

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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

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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

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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)

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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

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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)

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Common Drugs in Athletic Training

• NSAIDS
• Antispasmodic
• Asthma Medications
• Gastrointestinal distress
• Dermatologic Medications
• See common drugs chart

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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),

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NSAIDS Contraindications

• 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

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NSAIDS Salicylates

• Properties
• Analgesic, antipyretic, anti-inflammatory,
  antiplatelet
• Types
• Asprin
• Choline Salicylate (Athropan)
• Magnesium Salicylate (Doans, Mobidin)
• Sodium Salicylate (Alka Seltzer)
• These are methods of absorption

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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

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Side Effects of Salicylates

• Gastrointestinal
• Hemtologic Effects
• Nephotoxicity
• Allergic reactions
• Reyes Syndrome (viral infections in children)
• Overdose (coma, circulatory failure, respiratory
  failure)
• Found to have no effects on athletic performance

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NSAIDS Non-Salicylate

• for relief of headache, myalgia, arthralgia
• Three types
• ibuprofen (Advil7)
• Ketoprofen (Ketopron7)
• naproxen sodium (Aleve7)

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NSAIDS Nonsalicylate
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NSAIDS Nonsalicylate
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NSAIDS Nonsalicylate

• General Does 200 mg tablets
• 400 mg every 4-6 hours not to exceed 1200mg
• Side Effects
• Similar to Sailcylates (no reyes syndrome)
• Not Banned by any athletic governing bodies
• No effect on athletic performance

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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

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Corticosteroids

• IndicationsSkin disordersNasal
  inflammationRespiratory ailmentsRheumatic
  disordersChronic inflammation

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Corticosteroids

• Administration
• Oral (nasal infections, respiratory ailments)
• Injection (chronic inflammation)
• Athletic Governing bodies have strict regulations
  of its usage

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Corticosteroids

• Side Effects
• Optic - eye pain
• Gastrointestinal
• Circulatory lasting skin hives, discoloration,
  burning itching
• Menstral irregularities
• Softening of cartilage (Delayed - over time)

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Non-Anti-Inflammatory Systemic Analgesics

• acetaminophen (Tylenol) analgesic OTC/RX mild to
  moderate pain
• Opiate Agonists - for severe pain
• Morphine
• Codeine
• Tramadol (Ultram) for moderate to severe pain
• Combination products for mild to moderate pain
  (Tylenol with codeine)

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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

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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

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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

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Asthma Medications - Consideration for Use

• Heart disease
• Other prescription medications
• If OTC drugs are ineffective within 1 hour seek
  prescription
• Banned substances

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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,
  Anti-cholinergics, Theophyllines can be extremely
  toxic resulting the seizures and cardiac
  arrhythmia.
• Ephedrine may cause heart attacks seizures and
  psychosis

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GI Distress

• H2 blockers prevent acid secretion (Tagamet,
  Zantax, Pepcid)
• May use pre-participation
• May be beneficial in preventing stitch
• Antacid

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Dermatological

• Antifungal (topical cortizone)
• Anti-virus (herpes)
• Anti-bacterial (ringworm)
• Anti-viral and bacterial are prescription
  medications