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How Psychoactive Drugs Affect Us

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HOW PSYCHOACTIVE DRUGS AFFECT US Part II 7th February 2014 Ms. Cathy Ngarachu Physiological Responses to Drugs • Determines how drugs affect people and why it is difficult to control their levels of use. • They include: • Tolerance to Drug • Tissue Dependence • Psychological Dependence & Reward-reinforcing action of drugs • Withdrawal Tolerance • Results from the body’s attempt to eliminate a drug that it treats as a toxin • With continued drug use the body tries to neutralize the toxic effects by: • Requiring larger amounts of the drugs to achieve the original effects • Degree of effects depend on the : • Amount used • Duration of use • Frequency of use • Individual’s chemistry • State of mind Kinds of Tolerance • Dispositional Tolerance • Speeds up the metabolism to handle the drug in order to eliminate it • Example: Increases the amount of cytocells and mitochondria in the liver to neutralize the drug….. So it will take more of the drug to achieve the same level of intoxication Kinds of Tolerance • Pharmacodynamic Tolerance • Results from the desensitization of nerve cells to the action of the drug • Ex. The nerve cells become less sensitive and begin producing an antidote or antagonist to the drug, ie. The brain will generate more opiod receptor sites. Kinds of Tolerance • Behavioral Tolerance: • Brain adjustments that affect behavior • Someone who is high may make himself appear sober when threatened, then revert back to the high state • Reverse Tolerance • Person has greater sensitivity to the drug, after prolong use, and the body’s ability to metabolize the drug decreases. • Ex. A person who has drunk a 12-pack of beer daily for ten years, may find themselves drinking 3-4 beers to achieve the effect due to tissue damage of the liver and kidneys. • Also, the person may stay drunk longer as the liver is no longer metabolizing the alcohol and the alcohol just continues to circulate in the body until it is eliminated. Kinds of Tolerance • Acute Tolerance: • The body’s immediate resistance to the effects of the drug • Ex. The brain and the body adapts instantly to the drug, as with tobacco • Select Tolerance: • The body will develop a tolerance to some effects of the drug, but not to other effects resulting in potentially fatal side-effects in high doses of the drug. • Ex: The body may not feel the euphoric effect, but the organs of the body may react adversely to the drug: respiratory function of the lungs and continue damage to the liver Kinds of Tolerance • Inverse Tolerance (Kindling) • Person becomes more sensitive to the drug as the brain chemistry changes • After months of using marijuana or cocaine with minimal effect, the drug user may get an intense effect/reaction • Greater risk for heart attack or stroke Development of Amphetamine Tolerance Over Time Desired effect Copyright, 2004, CNS Productions, 21 Inc. • Tolerance develops rapidly to amphetamines. As the body adapts to the toxin, the liver, brain, and other tissues become better able to handle greater amounts. One dose of amphetamine on day 1 can increase to 30 doses on day 100 to achieve the same effect. Tolerance usually develops with higher-dose chronic use. Low-dose infrequent use induces only minimal tolerance. (p.58) Tissue Dependence • Biological adaptation of the body to the drug such that the body comes to depend on the drug to stay in balance. • The tissues and organs of the body come to depend on the drug to stay functional • Ex. Alcoholic will need a drink to ward off the shakes • Heroin addict will need a fix to stop body aches, headaches Psychological Dependence & the Reward-reinforcing Action of the Drugs • Results from the action of the drugs on the brain chemistry • Pleasurable effects induce user to continual use • Recognized as an important factor that contributes to addiction • Altered states of distorted perceptions of pleasurable feelings prompt users to avoid life’s problems Withdrawal • Marked by unpleasant effects that follow the cessation of drug use as the body attempts to restore its chemical balance • Withdrawal can be so severe that the user will continue to use drugs to avoid withdrawal symptoms • Kinds of Withdrawal • Non-purposive Withdrawal • Purposive • Protracted Withdrawal Kinds of Withdrawal • Non-purposive: • Series of unpleasant or even life-threatening physiological effects that accompanies cessation of use by an addict • Example: Sweating, headaches, vomitting, diarrhea, body aches, tremors, • Purposive: • Emotional expectation of physical effects • Manipulative counterfeiting in an effort to obtain more drugs, money or sympathy Kinds of Withdrawal • Protracted withdrawal (environmental triggers and cues) • Flashback or recurrence of addiction withdrawal symptoms that trigger heavy craving for a drug long after detoxification • Cravings can be triggered by a sensation associated with prior use and can be strong enough to cause relapse • PAWS (Post Acute Withdrawal Syndrome) OPIOD EFFECTS VS WITHDRAWAL SYMPTOMS EFFECTS Withdrawal Symptoms Numbness Becomes painful Euphoria Anxiety, depression or craving Dryness of mouth Sweating, runny nose, tearing, increased salivation Constipation Diarrhea Slow pulse Rapid pulse Low blood pressure High blood pressure Shallow breathing , Coughing Suppressed cough Pinpoint pupils Dilated pupils Sluggishness Severe hyper-reflexes, muscle cramps Basic Pharmacology • Metabolism & Excretion • Metabolism is the ability of the body to process, use and inactivate drugs or food • Chief organ of metabolism is the liver • Metabolism rates vary depending on the age, gender, race, heredity, general health, emotional state, presence of other drugs, weight, tolerance and exaggerated or allergic reactions • Excretion is the process of elimination of those substances from the body • Chief organs of excretion are the kidneys via the Urethra • Other pathways of excretion is the sweat glands, & lungs The liver is most responsible for metabolizing, detoxi-fying, and eliminating drugs. The drug-laden blood enters through the portal vein, is processed by various enzymes, and then sent via the hepatic vein to the heart where it is then pumped to the rest of the body. If the alcohol and another depressant drug are taken together, they compete for the same enzymes so the liver allows the other to enter the circulatory system at full strength. The Liver Copyright, 2004, CNS Productions, 24 Inc. Desired Effects vs Side Effects • Desired Effects include: • Satisfying curiosity, getting high, self-medicating, gaining self confidence, increased energy, relieving pain, controlling anxiety, peer pressure, social confidence, boredom, altering consciousness, coping with isolation, competion, seeking oblivion • Side Effects: (Biopsychosocial) • Mild to moderate to fatal effects • Polydrug Use: • Combination of more than one drug • May use another drug to replace the unavailable one • Get a different feeling • Enhance effects • Counteract effects • Cross addiction LEVELS OF USE LevelsLevels ofof UseUse AbstentionAbstention ExperimentalExperimental Social/RecreationalSocial/Recreational HabitualHabitual AbuseAbuse AddictionAddiction Copyright, 2004, CNS Productions, 25 Inc. LEVELS OF USE • Abstinence: • Not using drugs, except accidentally • With true abstinence, drug craving cannot develop not matter how high hereditary and environmental predisposition factors are • Experimentation: • Infrequent use of a drug to satisfy curiosity • Only few exposures, no pattern of use develops • Problematic consequences can occur if user is pregnant, driving, has physical or mental illness, has an alergic reaction or has legal problems LEVELS OF USE • Social/recreational Use • Use has irregular pattern with small impact on person’s life • Same consequences of use can occur as with experimentation • Habituation: • Regular pattern of use and loss of some control over a drug with minimal harmful consequences • Drug Abuse • Continues to use despite negative consequences, including health, school, work, emotional well-being and drug use continues on a regular basis. LEVELS OF USE • Addiction/Dependency • Difference between abuse and Addiction is the Compulsion to use • Uses drug in larger amounts or for longer periods of time • Unsuccessfully tries to cut down or control use • Spends a great amount of time in activities to obtain drugs or recover from use • Gives up or reduces important social, occupational or recreational activities because of use • Continues use despite knowledge that drug use is causing physical or psychological problems Theories of Addiction • DSM IV-TR divides substance related disorders into substance use and substance induced disorders • Substance use disorders are divided into abuse and dependency • Substance-induced disorders include conditions that are caused by specific substances, intoxication, withdrawal, delirium, etc. • Theories of Addiction focus on the environment, the host (user) and agent (drug itself) and the interactions between them Theories of Addiction • The Disease Model AKA Medical Model • Addiction is a chronic, progressive, relapsing, incurable and potentially fatal disease • Triggered by drug use that reacts to biochemical and neurological irregularities. • Sees heredity as more important than environmental influences in moving a person to addiction • Addiction is characterized by impulsive use, loss of control, repeated attempts at abstinence, continuation of use despite negative consequences, and complications resulting from abuse Theories of Addiction • The Behavioral/Environmental Model
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