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, Aleve 7, 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 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 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 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 –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 mg every 4 hours –Magnesium Salicylate mg every 4 hours –Sodium Salicylate mg every 4 hours

Side Effects of Salicylates: 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 (Advil 7 ) –Ketoprofen (Ketopron 7 ) –naproxen sodium (Aleve 7 )

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