1. Finish up with Chapter Five Start thinking about interview
AGENDA
Quiz
Finish up with Chapter Five
Start thinking about interview
Start at slide #34

2. Chapter 5
How and Why Drugs Work
Instructor Ed Ramirez

3. Introduction
A common belief is that drugs can solve most of life’s serious physical, emotional, and medical problems. Although medications are essential to treatment for many diseases, excessive reliance on drugs causes unrealistic expectation that may lead to dangerous– even fatal consequences.
We’ve covered this so far in the semester, relaxing, escaping, etc.

4. Celebrities Just because they're legal doesn't mean that prescribed drugs are any less dangerous than illicit drugs. They are potentially deadly when taken in large doses or when combined with alcohol or other drugs. Sometimes it takes high-profile cases to remind us of the dangers.
Methaqualone, AKA Quaaludes (sedative)
Secobarbital, AKA Seconal (sleeping pill)
Pentobarbital and chloral hydrate (sleeping pills)
As many as 14 different drugs, including codeine (painkiller) and methaqualone, AKA Quaaludes (sedative)
Propofol

5. Some of the drugs used
Elvis, On August 16, 1977, he suffered a heart attack in his Graceland estate, and died as a result. His death came in the wake of many years of prescription drug abuse.
Jimi Hendrix-the cause of death as: "Inhalation of vomit due to barbiturate intoxication ( he took nine sleeping pills)
Heath Ledger-combined effects of Oxycodone,
Hydrocodone, Diazepam, Temazepam, Alprazolam, and Doxylamine.

6. What Killed Michael Jackson?
Propofol
Propofol is a potentially deadly drug in the wrong hands, and there is no room for error. "It's only designed for people trained to do advanced cardiac life support," Dombrowski says. "It induces a deep level of sleep and sedation, and it can cause your blood pressure to go down and your breathing to stop. You can die
Now Used In Missouri Executions

7. Chapter Five
In this chapter, we consider the factors that account for the variability of drug responses
What determines how the body responds to drugs and why some drugs work while others do not

8. Intended and Unintended Effects of Drugs
When physicians prescribe drugs, their objective is usually to cure or relieve symptoms of a disease.
However, drugs cause unintended effects that neither the physician nor the patient expected:
THESE ARE CALLED SIDE EFFECTS

9. Side effects- Unintended drug responses

10. Side effects

11. Common Side Effects of Drugs
Nausea or vomiting
Changes in mental alertness
Dependence
Withdrawal
Allergic reactions
Changes in cardiovascular activity

12. Opiate withdrawal Withdrawal “Side Effects”
Unpleasant effects that occur when use of a drug is stopped
Withdrawal “Side Effects”

13. Withdrawal

14. Common Side Effects of Drug
Figure 5-1: Common side effects with drugs of abuse. Almost every organ or system in the body can be negatively affected by the substances of abuse.

15. Dose-Response Dose Tolerance Potency
Many factors can affect the way an individual responds to a drug, including the following:
Dose
Tolerance
Potency

16. Dose-Response (continued)
Additional factors
Pharmacokinetic properties: Defined below
Rate of absorption
Manner distributed throughout the body
Rate metabolized and eliminated
Form of the drug
Manner in which the drug is administered
-the branch of pharmacology concerned with the movement of drugs within the body

17. Dose-Response Curve
Figure 5-2: Dose-response curve for relieving a headache with aspirin in three users. User A is the most sensitive and has 100% headache relief at a dose of 60 mg. User B is the next most sensitive and experiences 50% headache relief with a 600-mg dose. The least sensitive is user C: with a 600-mg dose, user C has no relief from a headache.

18. Margin of Safety
The range in dose between the amount of drug necessary to cause a therapeutic effect and a toxic effect.

19. Potency vs. Toxicity
Potency: The amount of drug necessary to cause an effect
Toxicity: The capacity of a drug to do damage or cause adverse effects in the body

20. Drug Interaction
A drug’s effect can be dramatically altered when other drugs are also present in the body
This effect is known as DRUG INTERACTION

21. Drug Interaction

22. Grapefruit and certain medications

23. Drug Interaction Cont’d
Additive effects
Effects created when drugs are similar and actions are added together
Antagonistic (inhibitory) effects
One drug cancels or blocks effects of another
Potentiative (synergistic) effects
Effect of a drug is enhanced by another drug or substance

25. OTC and Herbal drugs ae as likely to cause interactions problems.
Public must be educated about the interactions most likely to occur with drugs that are prescribed, self-administered legitimately.
OTC and Herbal drugs ae as likely to cause interactions problems.
Example- Decongestant contains mild CNS stimulants. If taken with Illegal drugs such as cocaine or amphetamines, can cause fatally affect in the heart and brain.
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26. Figure 05.B01A
© Monkey Business/Fotolia.com

27. Pharmacokinetic Factors
How does the drug enter the body?
How does the drug move from the site of administration into body’s system
How does the drug move to various areas (distribution)
How and where does the drug produce its effects
How is the drug inactivated, metabolized excreted from the body

28. Pharmacokinetics
The study of factors that influence the distribution and concentration of drugs in the body
Pathways
Conjugation- 2 compounds resulting in the formation of another
Adducts- draw towards

32. Adam Goldstein
Better known as DJ AM
Overdosed, August, 2009
CNS Depressants
Six pills where found in his stomach. An OxyContin capsule was lodged in his throat.

33. Onset vary
Figure 05.03: Relationship between the method of drug administration and drug effects.

34. Forms and Methods of Taking Drugs
Half way
Forms and Methods
of Taking Drugs
oral ingestion
inhalation
injection
topical application
Topical Application
-made to be put on the skin topical
lotions/creams
a topical drug/treatment
Half way
Drugs can be introduced into the body using various methods, such as pills, capsules, oral liquids, topicals, or injections.
© Oscar Knott/FogStock/Alamy Images

35. Oral ingestion
One of the most common and convenient ways of taking a drug is orally It is difficult to control the amount of drug that reaches the site of action (Three Reasons)

36. Oral ingestion cont’d
The drug must enter the bloodstream passing through the wall of the stomach or intestines without being destroyed or changed into an inactive form
Materials in the stomach or intestines such as food may interfere with the passage
The liver might metabolized orally ingested drugs to rapidly, before they are able to exert an effect.

37. INHALATION
Some drugs are administered by inhalation into the lungs through the mouth or nose

38. Injection Intravenous (IV) Intramuscular (IM) Subcutaneous (SC)
Drug injection beneath the skin

39. Topical application
Drugs that readily pass though surface tissues such as the skin

40. Factors affecting Distribution
Most drugs are distributed throughout the body in the blood.
It takes approximately 1 minute for a drug to circulate throughout the body after it enters the bloodstream.
Drugs have different patterns of distribution depending on their chemical properties.
We have approximately 5 to 6 liters of blood

41. Factors affecting distribution
Their ability to pass across membranes and through tissues
Their molecular size (large versus small molecules)
Their solubility properties
Their tendency to attach to proteins and tissues throughout the body

42. Factors affecting distribution Cont’d
Blood is carried to the nerve cells of the brain in a vast network of thin-walled capillaries. Drugs are soluble in fatty oily solutions are most likely to pass across these capillary membranes known as “the blood-brain barrier”
THE BBB is defined as selective filtering between the cerebral blood vessels and the brain

43. The BBB

44. Required Doses for Effects
Threshold dose—the minimum amount of a drug necessary to have an effect
Plateau effect—the maximum effect a drug can have regardless of the dose
Example, aspirin, can effectively relieve your mild to moderate pain, but aspirin will not effectively treat your severe pains, regardless of the dose taken.

45. Time-Response Factors
The closer a drug is placed to the target area, the faster the onset of action.
Acute drug response:
Immediate or short-term effects after a single drug dose
Chronic drug response:
Long-term effects after a single dose

46. Time-Response Factors Cont’d
Important time factor that influences drug response is the interval between multiple administrations. If sufficient time for drug metabolism and elimination does not separate doses, a drug can accumulate within the body
Cumulative effect—the buildup of drug concentration in the body due to multiple doses taken within short intervals

47. Inactivation and elimination of drugs from the body
Half-life- Time required for the body to eliminate and/or metabolize half of a drug dose
Metabolism- Chemical alteration of drugs by body processes
Metabolites- Chemical products of metabolism
Usually makes it possible for the body to inactivate, detoxify and excrete drugs and other chemicals.
Exception: HEROIN becomes more active when it metabolizes.

48. Biotransformation
Biotransformation—the process of changing the chemical or pharmacological properties of a drug by metabolism.
The liver is the major organ that metabolizes drugs in the body.
The kidney is the next most important organ for drug elimination.

49. Inactivation and elimination of drugs from the body Cont’d
The body may eliminate small portions of drugs through perspiration and exhalation. Approximately 1% of consumed alcohol is eliminated in the breath and thus may be measured with a

50. Figure 05.B03: Family Matters: Genetics of Metabolic Enzymes and Alcoholism

51. Inactivation and elimination of drugs from the body Cont’d

52. Physiological Variables That Modify Drug Effects
AGE
Gender
Pregnancy
Changes in body size and makeup occur throughout the aging process
Variations in drug responses due to gender usually relate to differences in body size, composition or hormones
During pregnancy, unique factors must be considered when administering drugs.

53. Physiological Variables That Modify Drug Effects Cont’d
The increase demand can make the woman more susceptible to the toxicity of some drugs
As the fetus develops, it can be very vulnerable to drugs with Teratogenic- Something that causes physical defects in a fetus

54. Teratogenic
Remember from chapter 3??

55. Adaptive Processes
Figure 05.04: The relationship and consequences of adaptive processes to drug abuse. The processes discussed in the text are highlighted in the figure.

56. Adaptive Processes Your body systems are constantly changing
Drugs sometimes interfere with the activity of the body’s systems and compromise their normal workings
Stimulants can dangerously increase the heart rate, blood pressure and can cause heart attacks
Depressants can diminish the brain activity, resulting in unconsciousness and loss of breathing reflexes

57. Figure 05.T02: Tolerance, Dependence, and Withdrawal Properties of Common Drugs of Abuse

58. Figure 05.HN01A: Here and Now: Drug Test Results Can be Flawed
THE POPPY SEEDS
Figure 05.HN01A: Here and Now: Drug Test Results Can be Flawed
Data from Fiore, K. “APA: Drug Test Results Often Flawed.” MedPage Today. 23 May Available Accessed March 2, 2011.

59. Figure 05.HN01B: Here and Now: Drug Test Results Can be Flawed

60. Tolerance to drugs
Reverse tolerance (sensitization): Enhanced response to a given drug dose; opposite of tolerance
Cross-tolerance: Development of tolerance to one drug causes tolerance to related drugs

61. Drug Dependence
Drug dependence can be associates with either physiological or psychological adaptations.
Physical dependence reflects changes in the way organs and systems in the body respond to a drug, whereas psychological dependence is caused by changes in attitudes and expectations.

62. (e.g.,withdrawal and rebound)
Drug Dependence
Physical
Dependence
(e.g.,withdrawal and rebound)
Psychological
Dependence
(e.g., craving)

63. Physical Dependence
In general, the drugs that cause physical dependence also cause a drug withdrawal phenomenon called, “rebound effect”
“This is a form of withdrawal; paradoxical effects that occur when a drug has been eliminated from the body”
Physical dependence , drug withdrawal- two opposite things and that seems impossible but is actually true or possible

64. Physical Dependence Cont’d
Cross Dependence- dependence on a drug can be relieved by other similar drugs
Examples- Benzodiazepines and other CNS depressants can be used to treat the abstinence syndrome experienced by the chronic alcoholic
Methadone, long acting narcotic, to treat heroin withdrawal

65. Psychological Factors Affecting Drug Effect
Individual’s mental set
The collection of psychological and environmental factors that influence an individual’s response to a drug
Placebo effects
Effects caused by suggestion and psychological factors independent of a pharmacological activity of a drug
Placebo- From the Latin word meaning, “I shall please.”

66. Addiction and Abuse
The use of the term addiction is sometimes confusing. It is often used interchangeably with dependence, either physiological or psychological in nature; other times, it is used synonymously with the term drug abuse. A more accurate definition is the compulsive drug use despite negative consequences.

67. Addiction and Abuse (continued)
Factors affecting variability in dependence/addiction:
Hereditary factors (genetic variants); responsible for 40–60% vulnerability
Drug craving

68. Addiction and Abuse (continued)
Other factors contributing to drug use patterns:
Positive versus negative effects of drug
Peer pressure
Home, school, and work environment
Mental state

69. Figure 05.B04: Family Matters: Family Addictions and Genetics

70. Addiction and Abuse (continued)
Other factors contributing to drug use patterns
Positive versus negative effects of drug (dysphoric is the opposite of euphoric)
Peer pressure
Home, school, work environment
Mental state

71. Dysphoric Dysphoric is the opposite of euphoric
Characterized by unpleasant mental effects
Dysphoric is the opposite of euphoric
Figure 5.4 again
DYSPHORIA- a state of dissatisfaction, anxiety, restlessness, or fidgeting.

72. Questions