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5/23/2012

5/23/2012. What do you think of when you hear the word “pharmacology”?. Pharmacology. Delete text and place photo here. After completing this unit, you will be able to describe: Where drugs come from Mechanism of action of drugs How drugs are grouped by classes

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5/23/2012

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  1. 5/23/2012 What do you think of when you hear the word “pharmacology”?

  2. Pharmacology Delete text and place photo here. • After completing this unit, you will • be able to describe: • Where drugs come from • Mechanism of action of drugs • How drugs are grouped by classes • Dis/advantages of drug admin. • 4 major processes of pharmacokinetics • Conversion between systems • Basic medication dosage calculations Delete box or call out text or list of services goes here http://www.youtube.com/watch?v=Btqlf6Rs_Ek

  3. Pharmacology Pharmacy: Originated from the Greek term ‘Pharmakon’ which means medicine or drug. Pharmacology: is the study of drugs Where do they come from? 1. Natural sources (plants/ animals) 2. Microscopic organisms (bacteria, fungi, molds) 3. Synthetics & Bioengineering

  4. Sources: Natural • Pharmacognosy: study of drugs naturally derived from plants or animals* Drug Therapy traces back to the earliest recorded history • * Oldest herbal medicine described in Egyptian Papyrus Scroll • included gargles, suppositories, ointments, and inhalations (all plants) • We still use some plant and animal derived meds today • Plants were main source until early 1900s • 1921- Banting & Best extracted insulin from a pancreas and tested it on diabetic dogs in attempt to lower blood sugar (tested on humans in 1922 and became sole source of insulin for 60 years) • How do you feel about animal testing? • Downfalls of natural meds: poor absorption, quick breakdown, slow & expensive process, impurities, scarce

  5. DRUGS obtained from plants/animals

  6. Sources cont… Delete text and place photo here. Microscopic Organisms: Penicillin- one of the 1st non-plant or animal derived drugs - produced by a mold - Sir Alexander Fleming isolated Penicillin in 1928 Most of today’s infection fighting drugs are made from microorganisms Chemists & molecular biologists make all antibiotics this way

  7. Sources cont… http://www.youtube.com/watch?v=d9ouk_46xA8 • Synthetics & Bioengineering: • - Chemists have resolved many natural medicine problems • Medicinal chemistry: modifies natural products by synthetic production • Injectable meds have modified into forms that can be taken orally, inhaled, topically • Number of doses have decreased • Aspirin, (once extracted from willow bark) is now synthetically produced • Bioengineering has allowed us to produce drugs that were once only available from animals by genetically altering bacteria (1st-insulin) • Until 1980, insulin was taken from pigs/cows (foreign) • Scientists insert human gene for insulin into bacteria causing insulin production Delete text and place photo here.

  8. What do you think??? • Jack Kevorkian, a medical doctor, is most famous for his support for the individual\'s right to die and assisted suicides. In 1999 Dr. Kevorkian was sentenced to ten to twenty-five years in prison when a jury found him guilty of second-degree murder, delivery of a controlled substance and administering a lethal injection to a terminally ill man. His activities stirred debate and brought the right to die into the spotlight of media attention. Studies indicate that most doctors seem to support a terminally ill patient’s right to end his own life. • http://www.youtube.com/watch?v=YxuTMH7b1VU&feature=related http://www.youtube.com/watch?v=XDOzT3_HfwI&feature=related

  9. http://www.youtube.com/watch?v=4ghMB4yH6nw&feature=related

  10. Case Study

  11. 5/__/2012 How do you feel about the abuse of pharmaceutical distribution to patients from medical professionals?

  12. 5/29/2012 What do you think can be done to help decrease the number of patients that become dependant on prescription drugs? Is this a problem?

  13. Pharmacotherapeutics Drugs: Chemicals that affect the function of living organisms. HOW? They produce their effect by interacting with other chemicals in the body (MOA) • Pharmacotherapeutics: • Examines the MOA of drugs • Describes the effects produced by a drug • Determines what dose of a drug is needed to produce desired effect • Determines what dose of a drug produces toxic effects

  14. Mechanisms of Action • -Drugs w/ same MOA belong to same therapeutic class. • - they produce their effects the same way • - although same class, each is a different chemical • - (Benadryl & Claritin both treat allergies, both in antihistamine therapeutic class but different chemical) • - Antihistamines work by BINDING to the same chemical (a protein in the body, a histamine receptor) • Most drugs use 1 of 4 MOAs which all rely on the lock & key principle • Drug is key, lock is the chemical in body to which the drug binds (usually a protein) Delete text and place photo here.

  15. MOAs continued… • -Four most common MOAs: • Binding to & stimulating a receptor in body • -Receptors are proteins found in cells which cause a response within a cell when the receptor is stimulated by a naturally occurring key • - Different cell types = different receptors • - Drugs that work according to this MOA imitate the natural key within the body, called agonists or mimetics • Binding to & Blocking a receptor in body • - some bind with no response other than to prevent the natural key from binding • - drugs that work according to this MOA are called antagonists or blockers Delete text and place photo here.

  16. MOAs continued… -Four most common MOAs cont: 3. Inhibiting an Enzyme - Enzymes are proteins in the body that speed up chemical reactions - Two types of enzymes 1. Anabolic: play a constructive role 2. Catabolic: play a destructive role - They increase concentration of something if they slow its destruction - They decrease concentration if they slow its production - These drugs are enzyme inhibitors 4. Decreasing the movement of a chemical across a cell membrane Delete text and place photo here.

  17. MOAs continued… • pumps or channels in the cell membrane control movement of chemicals in and out • pumps can be turned on/off, channels can be opened/closed • Some drugs work by inhibiting specific pumps and others block specific channels

  18. Case Study #2

  19. MOA Demonstration • Divide Class in

  20. 5/6/2010 • What do you find most confusing about pharmacology so far? What should we refocus on if anything at this point?

  21. 5/12/2010 List an example of a common side effect associated with medications. Why do they occur?

  22. Side Effects • - Many drugs produce undesired effects • Any effect produced by a drug that is not the desired effect is known as a side effect • 2 categories: Local & Systemic • Local Side Effects: occur before a drug is absorbed into the bloodstream • Ex. Aspirin can irritate stomach lining • Ex. Inhalers can cause a dry throat/cough • Ex. Antibiotics can cause diarrhea when they kill naturally occurring bacteria • Systemic Side Effects: take place after a drug is absorbed into the bloodstream • Allergic reactions can occur since drugs are not a natural part of the body

  23. Side Effects -Systemic effects often occur because the drug effects cell other than the target cells. EX: Bronchodialators produce the desired effect by stimulating epinephrine receptors in the respiratory passages however they also increase the heart rate by stimulating epi receptors in the heart & cause insomnia by stimulating epi receptors in the brain - Side effects will continue to be an issue until science develops a way of delivering drugs only to the desired targets within the body!

  24. Therapeutic Classes Classes: Drugs in a therapeutic class produce their effect in the same way however differences between drugs within a class do exist. (Benadryl/Claritin) • One drug in a class may upset one’s stomach while another may cause drowsiness • Physicians must consider these differences when prescribing a drug

  25. Classes • 1 Angiotensin Converting Enzyme Inhibitors • -Angiotensin is a protein that occurs naturally in the body; also a powerful vasoconstrictor used to regulate BP (narrow vessels increase BP) • -Overactive angiotensin causes hypertension • -ACE activates angiotensin, therefore if ACE is inhibited or blocked, the amount of angiotensin produced by the body is reduced. • This reduction dilates/widens the blood vessels and lowers BP • ACE inhibitors are a drug class that regulate BP by inhibiting angiotensin converting enzyme • Available only by prescription

  26. 5/13/2010 • How many of you would be interested in some extra credit product points on your final exam???? Would you be willing to sign up as a group for Relay for Life? • Would you go to the Ronald McDonald House on a Saturday? • Would you take part in a RMD Walkathon?

  27. ACE inhibitor facts Representative drugs: Accupril, lotensin, Prinivil, Vasotec, Zestril Indications: Hypertension (High BP) Common Side Effects: headache, dizziness

  28. Classes: Beta-1 Blockers • Beta-1 Blockers: • Naturally released epinephrine (adrenalin) and norepinephrine are released in low amounts • -release at higher level when startled, frightened, or anxious • -they increase heart rate when they bind to and stimulate beta-1 receptors in the heart • -Beta-1 Blockers bind to beta-1 receptors without stimulating them (blocking epi/nor) and decreasing HR • -EX. Lopressor, Tenormin, Toprol • -Indications: hypertension, tachycardia • -Common Side effects: dizziness, drowsiness

  29. Classes: Beta-2 Agonists EX. Ventrolin, Proventil, Serevent, Alupent, Brethine Indications: Asthma, Emphysema Common Side Effects: Tremors, Increased HR, insomnia 3. Beta- 2 Agonists: Beta-2 receptors are responsible for the function of smooth muscles that control body functions -control functions that you don’t control -B2A produce same effects in lungs as natural epi by mimicking and stimulating the receptors -oral form- tablets, liquids, inhalers

  30. Classes: Antihistamines 4. Antihistamines: Histamines are released from mast cells when exposed to allergen - Histamine binds to and stimulates histamine receptors, causing allergy symptoms (sneezing, watery eyes, runny nose, etc) -Antihistamines bind to receptors but do not stimulate them - their presence prevents histamine from binding and reduces the allergic symptoms EX: Allegra, Benadryl, Claritin, Zyrtec Indications: itching, nasal congestion, seasonal allergies Common side effects: drowsiness, dry mouth

  31. 5/19/2010 (Q of D) 3 questions you could potentially ask Mr. Kevin Bailey after his presentation

  32. Classes: H2- Antagonists 5. H2- Antagonists: Histamines are not only allergy related but also aid in digestion - food in the stomach triggers its release which causes secretion of hydrochloric acid - It first binds to and stimulates H2 receptors in the stomach -too much histamine leads to excess hydrochloric acid which can cause ulcers and other gastrointestinal disorders -H2 antagonists bind & block these receptors decreasing the amount of acid after meals EX. Tagamet, Pepcid, Zantac. Indications: gastroesophageal reflux, ulcers Common Side Effects: diarrhea, headache

  33. Classes: Proton Pump Inhibitors 6. Proton Pump Inhibitors: Parietal cells in the stomach use proton pumps to move hydrogen ions into cells – parietal cells use the H ions to produce stomach acid -proton pump inhibitors turn off the pumps and reduce stomach acid EX: Prilosec Indications: gastroesophageal reflux, ulcers Common Side Effects: diarrhea, headache

  34. 5/21/2010 • Why is it not possible to have only one class of drugs or one MOA?

  35. Classes: Narcotic Analgesics • Narcotic Analgesics: • - Endorphins are natural occurring pain relievers produced by our bodies • -they inhibit nerve cells that carry pain • impulses to our brain when they bind to • and stimulate endorphin receptors in • the spine • -N.A. bind to and stimulate the same receptors which reduces pain • -most potent pain meds avail/ script only • Representative Drugs: Morphine, codeine, Demerol, Vicodin, Percodan • Indications: severe pain • Common Side Effects: Drowsiness, slow & shallow respirations, constipation

  36. Classes: Nonsteroidal Anti-inflammatory Drugs 8. Nonsteroidal Anti-inflammatory Drugs: - prostaglandins are chemicals produced in the body that cause pain & swelling associated with inflammation -Ex: prostaglandins produced when an ankle is twisted/sprained -prostaglandins are made by an enzyme called prostaglandin synthase -NSAIDs inhibit prostaglandin synthase which then reduces the production of prostaglandins, hence less pain (script and non script) -Representative Drugs: aspirin, motrin, advil, relafen, naprosyn, aleve -Indications: mild-mod pain, inflammation, fever -Common side effects: stomach irritation

  37. Classes: Reverse Transcriptase Inhibitors 9. Reverse Transcriptase Inhibitors: -The human immunodeficiency virus (HIV) is the virus that causes AIDS - the virus infects the immune system cells by injecting a cell with a small piece of its ribonucleic acid (RNA) - RNA builds protein in the body and cells are made of protein - DNA determines a cells genetic makeup -HIV virus uses its own RNA to reproduce itself in the body (RNA is converted into DNA (deoxyribonucleic acid ) in the cell -The cell then produces thousands of new viruses which then infect thousands of others

  38. Classes: Reverse Transcriptase Inhibitors cont.. A natural enzyme, reverse transcriptase, is needed to convert RNA to DNA. Reverse transcriptase inhibitors decrease the activity of the enzyme, slowing down the progress of HIV Representative Drugs: AZT, Combivir, Sustiva, Retrovir Indications: HIV Infection Common Side Effects: anemia, fever, rash, headache, lack of energy, nausea, vomiting, diarrhea, stomach pain, cough, shortness of breath, sore throat

  39. Classes: Statins • Statins: • Liver produces much of body’s cholesterol • - For some, a diet change is not sufficient in lowering cholesterol levels • HMG CoA reductase enzyme is needed by the liver to produce cholesterol • Statins (drugs) inhibit HMG CoA r.e., thus reducing the production of cholesterol • (most commonly prescribed drugs in US) • Rep Drugs: Lipitor, Pravachol, Zocor • Indications: high cholesterol (beyond diet) • Common Side Effects: nausea, vomiting, diarrhea, liver damage

  40. Routesofadministration.. http://player.discoveryeducation.com/index.cfm?guidAssetId=A4B2B75F-C34E-41E5-9DFD-476568A30FA8&blnFromSearch=1&productcode=US Routes of administration are the methods used to get a drug into the tissues of the body in order to produce the desired effects -Two main routes: Oral & parenteral Oral: most common route -drug is swallowed in the form of a tablet, capsule, or a liquid -Usually takes 30-60 minutes before working Time needed before a drug takes effect is the onset of action

  41. 5/25/2010 • Get into groups of 4 please!

  42. 5/28/2010 What are your goals for next school year?

  43. Routesofadministration.. -Parenteral route: all other methods other than oral administration -Onset of Action for parenteral can be very quick -4 most common parenteral routes: -1. Metered-Dose Inhaler: used to deliver meds directly to lungs for rapid action (min. side effects) -2. Transdermal Patch: deliver a constant amount of drug over an extended period of time (usually 24 hr) -convenient, consistent if hairless, no cuts etc -3. Injections: used for rapid effect (ex. anesthesia) - subcutaneous (SC) (arm, abdomen, front thigh) - usually 25 gauge or smaller, ½ inch in length (larger number = thinner needle) - intramuscular (IM) (shoulder, buttocks, thigh) - usually 23 gauge or larger, 1-1 ½ inches -4. Intravenous; directly in vein, rapid or irritating for SC/IM tissue

  44. Pharmacokinetics • In order for a drug to be effective, the proper plasma concentration of the drug needs to be achieved • High enough for effect but not too high for harmful effects to occur Therapeutic Range: min-max range to achieve objective Pharmacokinetics: study of 4 processes that affect plasma concentration of drugs (changes based on weight, gender, age and liver function)

  45. Pharmacokinetics -1. Absorption: the process by which a drug enters the plasma -oral: must dissolve in stomach fluid or intestines, pass through membranes of GI track & blood vessels before reaching the plasma -occurs through diffusion (molecules in an area where concentrated randomly move to an area where they are less concentrated (no set direction) - 2 characteristics which determine the speed of absorption: dissolve time & how easily they can diffuse through the membranes -2. Distribution: where the drug goes after entering plasma (some binds to proteins, some leaves plasma and goes to tissues) -will be present in all bodily fluids, only small amount goes to where it will exert its effects

  46. Pharmacokinetics -3. Transformation: is the chemical change that takes place in a drug after it has been absorbed by the body. - most changes occur in liver as the liver alters the drug to make it more water-soluble for easy removal from the body and some changes destroy the activity of a drug -4. Elimination: process that removes drugs from the body -most drugs primarily eliminated in urine -also feces, sweat, tears, saliva, & breast milk

  47. DOSAGES • Effects of Individual Differences on Maintenance Doses: • Dosage: the amount of a drug to be administered • the amount and frequency are sometimes different for 2 people of the same body weight • other factors: activity of the digestive tract, percentage of body fat, age, malnutrition, dehydration, liver disease

  48. DOSAGES cont… • People responsible for administering drugs: • Must be certified or licensed in field • May need to pass administration test • Must take it seriously as errors can cause serious or even fatal consequences • Must have physician’s order • Written in client’s chart or script • Should include name of drug, amount of drug prescribed, frequency of administration, route of administration

  49. LABELS • LABELS • Known unit on hand: grams/mg of drug • Known dosage form: typical amount of drug for which you are given the g/mg equivalent (ex. Bottle of cough syrup indicates that there are 125 mg per 5 ml) • Dose Ordered: the amount of grams or mg ordered • Unknown amount to be given: what you are trying to determine/ the amount of medication to be given • (May require conversions if not listed in same units)

  50. THE END

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