Transcript Chapter 16
Chapter 16 Using Drugs Responsibly What Is a Drug? • A drug is a chemical in a medicine that affects one or more of the body’s biological functions. • Alteration can be to start, stop, speed up, or slow down a process. • A medicine is a drug (or combination of drugs) that is used to prevent illness, cure disease, aid healing, or suppress symptoms. • Drugs are classified according to the particular biological process they affect rather than by their chemical properties. Drug Laws • Drugs are categorized into the following five groups: – Prescription drugs – Over-the-counter drugs – Dietary supplements – Addictive drugs – Illegal drugs How Drugs Work • Many drugs act by interacting with specific cells in the body that carry receptors, which are proteins on the surface or inside a cell to which a drug or natural substance can bind and affect cell function. • When a drug binds to a receptor, it affects the biological processes of cells or organs. How Drugs Work How Drugs Work Unintended Harmful Effects of Drugs • Even though a drug may be intended to have a single effect, it often does not because it binds to different kinds of receptors on different cells. • Unintended drug actions are called side effects. • Some side effects include allergic reactions called drug hypersensitivity. Routes of Drug Administration • Drugs can be taken: – By mouth – By inhalation – By injection into the muscle or bloodstream – By implant under the skin – Through the skin – Through mucous membranes of the eyes, nose, vagina, and anus • Drugs remain active in the body for a relatively short time, often only a few hours. Effectiveness of Drugs • The dose of a drug is the amount that is administered or taken. • Effectiveness of a particular dose of a drug is influenced by: – Person’s body size – How rapidly the drug breaks down and is eliminated – The presence of other drugs or food in the body – The person’s mental state – Person’s expectations of the drug’s efficacy Effectiveness of Drugs Psychoactive Drugs • Psychoactive drugs alter thoughts, feelings, and sensations. • Psychoactive drugs include: – Tranquilizers – Sleeping pills – Mood modifiers Lifestyle Drugs • Lifestyle drugs are sold to basically healthy middle-class Americans. • Lifestyle drugs are used in the place of making healthy choices such as eating a diet of vegetables and fruit and staying active. Drug Company Advertising • Pharmaceutical companies market to doctors by “courting” them for business. • In the United States, pharmaceutical companies are also allowed to advertise directly to consumers through television and print media. The FDA and You • A number of tests are run on groups of volunteers to test a drug’s effectiveness. • Drugs are also watched for side effects. • Only after trials are done does the FDA give approval for sale. Drug Misuse, Abuse, and Addiction • Using any drug to the point where health is adversely affected or the ability to function in society is impaired can be defined as drug abuse. • Drug abuse refers to the person taking the drug being personally or socially impaired. • A drug is being abused if the user cannot control taking it and the drug is being used continually to mask anxiety, combat stress, or seek pleasure. Addiction • Progressive, chronic, primary disease characterized by: – Compulsion – Loss of control – Continued drug use despite adverse consequences – Distortions in normal thinking • Physical dependence (tissue dependence) is the biological adaptation to long-term exposure to a drug. Both illegal and legal drugs can cause physical dependence. Tolerance • Tolerance is the adaptation of the body to a drug so that larger doses are needed to produce the same effect. • The longer a drug is used, the more of that drug must be consumed to produce the desired effect. Withdrawal • Withdrawal is a consequence of physical dependence—withdrawal is experienced after the drug is no longer used. • Often it is uncomfortable and it may be fatal. • Symptoms are often opposite of the drug’s primary effects. Withdrawal • In general, withdrawal from nervous system depressants leads to: – Anxiety – Irritability – Susceptibility to seizures • Withdrawal from stimulants can produce: – Sleepiness – Depression – Loss of consciousness Psychological Dependence • Psychological dependence is the habituation manifested as an intense craving for the drug. • Compulsive drug-seeking behavior may destroy relationships, jobs, and families. Stimulants • Substances that increase the activity of the central nervous system and are referred to as “uppers.” • Common stimulants include cocaine, amphetamines, and caffeine. • Main effects include: – Increased mental arousal and physical energy – A state of euphoria • Long-term use causes physical and psychological dependence. Cocaine • Stimulant obtained from the coca shrub. • Induces euphoria, sense of power and clarity of thought, increased physical vigor, increased heart rate and blood pressure. • Continued use can result in: – Loss of appetite and weight loss – Malnutrition – Sleep disturbance – Altered thought and mood patterns Cocaine • Frequent cocaine sniffing can damage the nasal septum. • Routes of administration: – Sniffing (“snorting”) it as a white powder – Injecting it directly into the bloodstream – Smoking it in the form of “free base” or “crack” • Produces tolerance, physical dependence, and withdrawal. • Potential for psychological dependence with cocaine is very high. Amphetamines • Manufactured chemicals that stimulate the central nervous system • Most common are: – Dextroamphetamine – Methamphetamine – Dextromethamphetamine – “Ice” is a dangerous form that is smoked. • Produce a hallucinogenic effect that lasts for hours Amphetamines • Usually taken orally, but can be injected • Can be prescribed by physicians, but have little medical use • Produce feelings of euphoria, increased energy, greater self-confidence, increased ability to concentrate, increased motor and speech activity, perceived improvement in physical performance Amphetamines • Excessive use can cause: – Headaches – Irritability – Dizziness – Insomnia – Panic and confusion – Delirium – Crash – Tolerance – Mild physical dependence Caffeine • Natural substance found in a variety of plants used in making coffee, tea, chocolate, and soft drinks • Produces decreased drowsiness and fatigue, faster and clearer flow of thought, increased capacity for sustained performance, nervousness, tremors, insomnia, and inability to perform complex tasks Caffeine • Psychological dependence can result from chronic use and tolerance can gradually develop. • Mild withdrawal symptoms can occur when caffeine use is ceased, including: – Headache – Irritability – Restlessness – Lethargy Club Drugs • Consist of several psychoactive chemicals that are often used at social events • These include: – Ecstasy – GHB – Ketamine – Rohypnol Ecstasy • Methylenedioxymethamphetamine—an amphetamine that has become popular in recent years. • Also called “Ecstasy,” “Adam,” “XTC,” “Clarity,” “Essence,” MDMA, or MDM. • Users experience hallucinogenic effects and euphoria. • Stimulates the release of serotonin, producing a high that can last hours. GHB • Gamma-hydroxybutyrate • Also called “G” or “Liquid Ecstasy” • Causes sedation, increased sexual interest, relaxation, short-term amnesia • Very dangerous to mix with alcohol Ketamine • Is a dissociative psychedelic used medically as a veterinary and human anaesthetic. • Also called “K,” “Special K,” or “Cat Tranquilizer” • Causes hallucinations, bizarre behavior, psychosis Rohypnol • Flunitrazepam is a benzodiazepine used as a sleep medication favored for its short duration. • Also called “Ruffies” or “Roofies.” • Reduces anxiety, inhibition, and muscular tension. • Has received a lot of attention as a “date rape drug.” Ephedrine (Ephedra) • Amphetamine-like substance that acts as a central nervous system and cardiovascular stimulant • Also known as ma huang • Also sold as “herbal ecstasy” to alter consciousness Depressants • Reduce the level of arousal, motor activity, and awareness of environment • Increase drowsiness and sedation • Produce mild state of euphoria, reduction in inhibitions, feeling of relaxation • May impair mood, speech, and motor coordination Depressants • Carry the potential for: – Physical and psychological dependence – Tolerance – Withdrawal symptoms • If two or more depressants are taken at the same time, they produce an effect much stronger than either drug produces when taken alone (synergistic effect). Sedative and Hypnotic Drugs • By prescription only. • Sedatives promote mental calmness and reduce anxiety. • Hypnotics promote sleep or drowsiness. • Most common sedative-hypnotic drugs are called benzodiazepines, popularly known as tranquilizers. Barbiturates • Barbiturates are sedative-hypnotic drugs that include barbituric acid and its derivatives; these drugs include amobarbital, pentobarbital, phenobarbital, secobarbital, Tuinal, Rohypnol, and GHB. Opiates • Opiates are a group of chemically related drugs derived from the opium poppy; depress the central nervous system (CNS). • Cause physical dependence, habituation, tolerance, and serious withdrawal symptoms. • Can be fatal because of respiratory failure. • Morphine and heroin are derivatives of opium; they block nerve transmission in the CNS, suppressing mental and physiological functions. Marijuana • Forms: – Hashish—sticky resin of the Cannabis sativa plant – Ganja—dried tops of female plants – Bhang—contains smaller amounts of THC – Sinsemilla—potent form of marijuana • Active ingredient is THC. • Low doses of THC produce: – Euphoria – Sense of relaxation – Sometimes altered perception of time and space Marijuana • THC consumption can invoke: – – – – Confusion Anxiety Hallucinations Paranoia • Research indicates that marijuana contains carcinogens. Marijuana • Many states have legalized use for medical purposes, such as: – – – – – Nausea caused by chemotherapy Anorexia as a result of cancer AIDS Chronic pain Migraines Hallucinogens • Derived from as many as 100 kinds of plants and from chemical synthesis in the lab • Alter perception, thought, mood, sensation, and experience • Most often ingested orally • Produce tolerance but do not create physical dependence or symptoms of withdrawal; there is a danger of psychological dependence Phencyclidine (PCP) • PCP was originally used as an animal anesthetic; it is no longer legal and is used now only as an illegal recreational drug. • The effects of PCP vary, depending on the dose and route of administration; it can be: – A stimulant – A depressant – A hallucinogen Inhalants • Depressants of the CNS • Intended effect: Loss of inhibition • Unintended effects: – Dizziness – Amnesia – Inability to concentrate – Confusion – Impaired judgment – Hallucinations – Acute psychosis Inhalants • Chemical substances that vaporize rapidly and when inhaled produce various kinds of depressant effects similar to alcohol • Model airplane glue, nail polish remover, paint thinner, gasoline, aerosols, amyl nitrite, and chloroform • Do not produce tolerance or withdrawal, nor do they induce physical dependence • Can damage the kidneys, liver, and lungs Anabolic Steroids • Synthetic derivatives of the male hormone testosterone. • Taken orally or injected. • Produce increased lean muscle mass, strength, and ability to train longer and harder. • Side effects include liver tumors, jaundice, fluid retention, high blood pressure, severe acne, and trembling. Reducing Drug Use • People are overmedicated and overly dependent on drugs. • The healthiest approach is to be as free of drugs as possible. • Wellness is not achieved by taking drugs. • All drugs are dangerous, and illegal recreational drugs are especially dangerous.