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  1. 1. 1
  2. 2. DRUG EVALUATION Process of classifying drugs as either therapeutic or non-therapeutic and are approved by a governing agency 2
  3. 3. DRUG APPROVAL PROCESS1. Food and Drug Administration (FDA) - US  Agency in-charge of monitoring the use of drugs as well as its development.2. Bureau of Food and Drug Administration (BFAD) – Philippines Concerns of these agencies are 2-fold:  Whether the drugs are effective  Whether the drug is safe for human use 3
  4. 4. Drugs for approval should pass through 4 Stages of New Drug Development. 4
  5. 5. Stages of New Drug Development1. Preclinical Study2. Clinical Study 1. Phase I 2. Phase II 3. Phase III3. New Drug Application (NDA) review4. Post Clinical Study 5
  6. 6. Stages of New Drug Development1. Preclinical Study Starts with the discovery, synthesis and purification of drug Functions:  To know if with therapeutic value  Safe in animals 6
  7. 7. Stages of New Drug Development2. Clinical Study “testing in humans” stage. 3 phases:  Phase I ○ Tested in small # of healthy volunteers. ○ Initial info on the effects in humans  Phase II ○ Tested in small, selected population (10-150 subjects) ○ To evaluate the therapeutic effect in treating specific disease/pathologic condition.  Phase III ○ More cients (several hundredths-thousands) ○ Provides info on proper dosing and safety. 7
  8. 8. Stages of New Drug Development3. New Drug Application (NDA) Review  the drug is submitted to FDA for new drug application. 8
  9. 9. Stages of New Drug Development4. Post Clinical Study Known as “postmarketing surveilance” Final stage of drug approval process It surveys the drug’s harmful effects. 9
  10. 10. 10
  11. 11. Drug Classifications1. Therapeutic Use/Clinical Indications2. Physiologic/Chemical Action3. Prescribed (Ethical) Drug4. Non-prescription (Non-Ethical) Drugs5. Illegal Drugs 11
  12. 12. Drug Classifications1. Therapeutic Use/ Clinical Indications Examples:  Antibiotics ○ cefuroxime, penicillin, erythromycin  Laxatives ○ Bulk-forming  Sterculia [Normacol], methylcellulose (Citrucel) ○ Stool softeners  (Colace, Diocto) ○ Lubricants or emollient  Diuretics  Antacids 12
  13. 13. Drug Classifications2. Physiologic/ Chemical Action Examples: 1. Beta-adrenergic blockers ○ management of cardiac arrhythmias ○ block the action of epinephrine and norepinephrine ○ Ex. propanolol 13
  14. 14. Drug Classifications2. Physiologic/ Chemical Action Examples: 2. Anticholinergics ○ inhibit parasympathetic nerve impulses  responsible for the involuntary movements of smooth (GI, urinary, etc) ○ Ex. Atropine sulfate 14
  15. 15. Drug Classifications2. Physiologic/ Chemical Action Examples: 3.Cholinergics ○ drug that functions to enhance the effects mediated by acetylcholine 4. Calcium channel blockers ○ to decrease blood pressure ○ Antiepileptics ○ Ex. Dihydropyridine 15
  16. 16. Drug Classifications3. Prescribed (Ethical) Drug Requiring prescriptions Ordered/dispensed only by an authorize practitioner 16
  17. 17. Drug Classifications4. Non-prescription (Non-Ethical) Drugs Drugs available over the counter Not requiring any prescription for use Can be purchased directly by consumer Used to treat relatively minor problems and conditions Judged to be safe for used by the consumer without direct medical supervision 17
  18. 18. Drug Classifications5. Illegal Drugs Use for non-therapeutic purposes. Also referred as “recreational drugs” Drugs not approved by FDA/BFAD 18
  19. 19. 19
  20. 20. #10SOLVENT 20
  21. 21. #9 Psychedelic Mushrooms(hallucinogenic mushrooms ) 21
  22. 22. #8 Opium(addictive painkiller ) 22
  23. 23. #7 LSD(Lysergic Acid Diethylamide)most powerful hallucinogenic 23
  24. 24. #6Barbiturates / Benzodiazepines (a prescription medicine) 24
  25. 25. #5 Amphetaminesaffecting the amount of dopamine and serotonin in the brain 25
  26. 26. #4 Ecstasy Psycho therapeutic drugproduces euphoria and a feeling of well being, decreased levels of fear and anxiety and a physical stimulant and sensational effect in users. 26
  27. 27. #3 Cocaine (Coca plan)powerful stimulant, appetite suppressant and anesthetic 27
  28. 28. #2 Heroin/Diamorphinepowerful painkiller and users experience exhilaration, euphoria and a sense of well being. 28
  29. 29. #1Cannabis or Marijuana, Grass, Hemp, Weed, Pot, Hash, Dope slightly drunken but euphoric sensation 29
  30. 30. 30
  31. 31. Drug Standards and Legislation Drug Standards  The United Pharmacopoeia National Formulary (USP NF) ○ the current authoritative source for drug standards (revised every 5 years by a group of experts in nursing: pharmaceutics, pharmacology, chemistry, and microbiology) ○ Drugs included in the USP-NF have the standards for:  therapeutic use  client safety  quality  purity  strength  packaging  dosage form 31
  32. 32.  Drug Standards  International Pharmacopoeia – first published in 1951 by WHO ○ provides basis for standards in strength and composition of drugs worldwide ○ published in English, Spanish, and French (revised every 5 years) 32
  33. 33.  FEDERAL LEGISLATION  Purpose – to ensure safety (drugs that are impure, toxic, ineffective, or not tested before public sale)  do not include drug effectiveness and drug safety 1938: Food, Drug, and Cosmetic Act  empowered a governing body—the Food and Drug Administration (FDA) and Cosmetic Act of 1938  Purpose: to monitor and regulate the manufacture and marketing of drugs  FDA’s responsibility is to ensure that all drugs are tested for harmful effects, have labels with accurate information, drug literature that explains adverse effects 33
  34. 34.  FEDERAL LEGISLATION 1952: Durham-Humphrey Amendment  amendment to the FDA and Cosmetic Act of 1938  distinguished between drugs that be sold with or without prescription and those that should not be refilled without a new prescription (ex. Narcotics, hypnotics, or tranquilizers; must be labeled)  It also specified that all other drugs are approved for use to be considered non-prescription drugs 34
  35. 35.  1962: Kefauver-Harris Amendment  tightened controls on drug safety, especially experimental drugs, and required that adverse reactions and contraindications must be labeled and included in the literature  it added requirements that both prescription and non-prescription drugs be shown to be effective as well as safe  thalidomide tragedy1950 – pregnant European women who took the sedative-hypnotic thalidomide during their first trimester of pregnancy gave birth to infants with extreme limb deformities. 35
  36. 36. A German pharmaceutical company, Chemie Grünenthal at Stolberg,synthesized thalidomide inWest Germany in 1953.It had accidentally been discovered during a search for cheap antibiotics, but was soon marketedwith little evidence as a sedative.In 1961 the drug was found to be harmful to the unborn children of pregnant women 36
  37. 37. 1978: Drug Regulation Reform Act This reform act shortened the time in which new drugs could be developed and marketed.1992: Drug Relations Act The regulations were changed to increase the approval rates of drugs used to treat AIDS and cancer The pharmaceuticals pay a users fee at the time they file the application for the new drugs (for FDA approval process). 37
  38. 38. 1997: The Food and Drug Administration Modernization Act 5 Provisions included in this act: Review and use of new drugs is accelerated. Drugs can be tested in children before marketing. Clinical trial data is necessary for experimental drug for serious or life- threatening health conditions. Drug companies are required to give information on “off-label” drugs (non- FDA approved drugs) and their uses and costs Drug companies that plan to discontinue drug must inform health professionals and clients at least 6 months before stopping drug production 38
  39. 39. LEGAL REGULATIONS OF DRUGS1. Pregnancy Categories Reviews drug labeling information on pregnancy and risk effects to the fetus 39
  40. 40. Drug Pregnancy Categories CATEGORY A: No risk to fetus. Studies have not shown evidence for fetal harm. CATEGORY B: No risk in animal studies, and well-controlled studies in pregnant women are not available. It is assumed there is little to no risk in pregnant women. CATEGORY C: Animal studies indicate a risk to the fetus. Controlled studies on pregnant women are not available. Risk versus benefit of the drug must be determined. CATEGORY D: A risk to the human fetus has been proven. Risk versus benefit of the drug must be determined. It could be used in life-threatening conditions. CATEGORY X: A risk to the human fetus has been proven. Risk outweighs the benefits and drug should be avoided during pregnancy. 40
  41. 41. LEGAL REGULATIONS OF DRUGS2. Controlled Substances  Comprehensive Drug Abuse Prevention and Control Act of 1970 known as “Controlled Substance Act” ○ To improve the administration and regulation of manufacturing, distribution, and dispensing of drugs found necessary to be controlled ○ Consist of 5 classifications or schedules of controlled substance ○ The degree of control, the condition of record keeping, and the particular order form required, and other regulation depends on these classifications. 41
  42. 42. LEGAL REGULATIONS OF DRUGS2. Controlled Substances Drug Enforcement Administration (DEA)  Organize to enforce the Controlled Substance Act  To gather intelligence, train and conduct research in the area of dangerous drug and drug abuse 42
  43. 43. LEGAL REGULATIONS OF DRUGS3. Generic Drugs Drug which is produced and distributed without patent protection. Drugs which may still have a patent on the formulation but not on the active ingredient It must contain the same active ingredients as the original formulation Identical/bioequivalent to the brand name counterpart since these drugs should be identical in dose, strength, route of administration, safety, efficacy and intended use. 43
  44. 44. LEGAL REGULATIONS OF DRUGS4. Orphan Drugs Drugs that have been discovered but not financially viable and therefore have not been “adopted” by any drug company. 44
  45. 45. Drug Nomenclature Chemical Name  describes the drug’s chemical structure  Chemical constitution of the drug & the exact placing of its atoms or molecular groupings. Generic Name (nonpropriety names)  Common name or non-proprietary name for the drug ○ this name is not owned by any pharmaceutical (drug) company and is universally accepted Brand Name or Trade Name (proprietary name) ○ also chosen by the drug company and is usually a registered trademark owned by that specific manufacturer ○ Uses the symbol ® 45
  46. 46. Drug NameChemical Name: 0-[(2S)-3-mercapto-2- methylpropionyl]-L- proline[MW217.29]Generic Name: captoprilTrade Name: CapotenOfficial Name: captopril 46
  47. 47. Drug Uses1. Symptomatic treatment.  ANTI-EMETIC DRUGS2. Preventive drug  helps the body avoid disease.  VACCINES & TOXOIDS3. Diagnostic drugs  help the physician determine whether a disease is present4. Curative drugs  eliminate the disease.  ANTICANCER AGENT & ANTIBIOTICS5. Health maintenance drugs  help the body to function normally.  VITAMINS & MINERALS6. Contraceptive drugs  prevent pregnancy.  ORAL CONTRACEPTIVES/SPERMICIDAL AGENTS 47
  48. 48. Properties of Ideal Drug1. Effectiveness:  A drug that elicits the response it was meant to.  It is the most important property.  No effect=no justification of use (FDA approved with appropriate experiments). 48
  49. 49. Properties of Ideal Drug2. Safety:  Pharmakon = poison in Greek  Safe even at high concentrations and for long periods of administration (no such thing as a safe drug) ○ Reduced by proper administration (iv, im, sc, etc…) ○ No habit forming aspects ○ No side effects  ( excessive dosage of opoid analgesics carries a risk of respiratory failure, cancer drugs increase infections, aspirin causes gastric ulcer etc…) 49
  50. 50. Properties of Ideal Drug3. Selectivity:  One that elicits only the response for which it is given  Selective for specific reaction with no side effects (there is no such thing) ○ Drowsiness can be caused by antihistamines ○ Morning sickness, cramps, and depression can be caused by oral contraceptives ○ Constipation, urinary hesitance, and respiratory depression can be caused by morphine 50
  51. 51. Additional Properties of Ideal Drug (no drug is ideal!)1. Reversible action  Effects be reversible, i.e., removal/subside w/i specific time (1/2 life is short but potent during that time)  Example: General Anesthetic; Contraceptives 51
  52. 52. Additional Properties of Ideal Drug (no drug is ideal!)2. Predictability  Know how patient will respond3. Ease of Administration  Number of doses should be low and easy to administer  increase compliance & decrease errors ○ Diabetic patient: Multiple daily injection of insulin ○ Intravenous infusion 52
  53. 53. Additional Properties of Ideal Drug (Continued)4. Freedom from drug interactions  Should not augment or decrease action of other drugs or have adverse combined effects ○ Respiratory depression caused by diazepam (Valium), which is normally minimal, can greatly be intensified by alcohol. ○ Antibacterial effects of Tetracycline can be greatly reduced by taking iron or calcium supplements 53
  54. 54. Additional Properties of Ideal Drug (Continued)5. Low Cost  Easy to afford (especially with chronic illness) ○ Growth hormone (somatrem) costs between $10,000 and $20,000 ○ Lifelong medication: hypertension, arthritis, diabetes 54
  55. 55. Additional Properties of Ideal Drug (Continued)6. Chemical Stability  No lose of effectiveness with storage7. Possession of a simple generic name  Easy to remember and pronounce ○ Example: Viagra (sildenafil); Tylenol (acetaminophen) 55
  56. 56. Because No Drug is Ideal…….. Because no drug is ideal…….  No medications are ideal  No drug is safe  All drugs produce side effects  Drug responses may be difficult to predict  Drugs may be expensive  Drugs may be hard to administer All members of health care team must exercise care to promote therapeutic effects and minimize drug induced harm 56
  57. 57. Therapeutic Objective To provide maximum benefit with minimum harmFactors that determine Intensity of Response Administration- dosage size and route Pharmacokinetic processes Pharmacodynamics Individual Variations 57
  58. 58. Therapeutic Objective1. Administration- dosage size and route - Because of errors in administration routes and dosage and at wrong time there are many discrepancies in what patient gets and could cause more harm than good - Errors could be made by pharmacists, physicians, or nurses - Should give patients complete instruction about their medication and how to take it 58
  59. 59. Therapeutic Objective2. Pharmacokinetic processes - Determines how much of an administered dose gets to its sites of action ○ 1) drug absorption ○ 2) drug distribution ○ 3) drug metabolism ○ 4) drug excretion 59
  60. 60. 60
  61. 61. Therapeutic Objective (continued)3. Pharmacodynamics pharmacodynamic processes determine the type of response and intensity Once a drug has reached its site of action, it must first bind to its specific target site at (RECEPTOR)Receptor  may be a chemical, a protein on a cell or in blood or tissue spaces, or on a bacteria or virus  Ex. heparin, antibody, leukotriene receptor (new), penicillin, etc 61
  62. 62. Therapeutic Objective (continued)3. Pharmacodynamics Series of events that result in response such as inhibition of: 1. Clotting 2. Peptidoglycan synthesis 3. Inflammation 4. Blocking of virus 62
  63. 63. Therapeutic Objective (continued)4. Sources of individual variation Each patient is unique in ability to respond and to how they each respond, but formation of “IDEAL DRUG” will lessen this variation ○ Age- very important factor ○ Sex- due to hormonal differences ○ Weight  less effective and longer lasting in obese individuals (storage in fat) ○ Kidney & liver functions - elimination of drug ○ Genetic variables- tolerance, allergy (though not always genetic) 63
  64. 64. Factors that determine the intensity of drug response 64
  65. 65. Summary To promote desired effects and minimize adverse effects, we need to understand  Pharmakokinetics  Pharmacodynamics  In addition ○ Sources of individual variation in drug response 65
  66. 66. Key Points The most important properties of an ideal drug are: effectiveness, safety, and selectivity. If the drug is not effective, it should not be used. There is no such drug as safe drug: all drugs can cause harm. There is no such thing as selective drug: all drugs can cause side effects. The objective of drug therapy is to provide maximum benefit within minimum harm. Because all patients are unique, drug therapy must be tailored to each individual. 66