N215 Unit 3 Chapter 12 Drug Misuse Flashcards
Sedatives and Sedative-Hypnotics
Sedatives, also known as tranquilizers, are prescribed for sleep disorders and certain forms of epilepsy. The two primary classes of sedatives are the barbiturates and the nonbarbiturate sedative-hypnotics. Their actions, indications, safety profiles, and addictive potential are roughly equivalent. Physical dependence, psychological dependence, and tolerance develop when these agents are taken for extended periods at high doses (see chapter 2 ). Patients sometimes abuse these drugs by faking prescriptions or by sharing their medication with friends. Sedatives are commonly combined with other drugs of abuse, such as CNS stimulants or alcohol. Addicts often alternate between amphetamines, which keep them awake for several days, and barbiturates, which are needed to help them relax and fall asleep.
Many sedatives have a long duration of action: Effects may last an entire day, depending on the specific drug. Users may appear dull or apathetic. Higher doses resemble alcohol intoxication, with slurred speech and motor incoordination. Death may result from barbiturate overdose. Four commonly abused barbiturates are pentobarbital (Nembutal), amobarbital (Amytal), secobarbital (Seconal), and a combination of secobarbital and amobarbital (Tuinal). The historic use of barbiturates in treating sleep disorders is discussed in chapter 14 , and their use for epilepsy treatment is presented in chapter 15 .
The medical use of barbiturates and nonbarbiturate sedative-hypnotics has declined markedly over the past 20 years. Overdoses of these drugs are extremely dangerous. They suppress the respiratory centers in the brain, and the user may stop breathing or lapse into a coma. Withdrawal symptoms resemble those of alcohol withdrawal and may be life threatening.
What drug classes and drugs are often misused?
CNS DEPRESSANTS page 111
Sedatives and Sedative-Hypnotics page 111
Opioids page 111
Ethyl Alcohol page 112
CANNABINOIDS page 113
Marijuana page 113
HALLUCINOGENS page 113
LSD page 113
Other Hallucinogens page 114
CNS STIMULANTS page 114
Amphetamines and Methylphenidate page 114
Cocaine page 115
Caffeine page 115
NICOTINE page 115
Tobacco Use and Nicotine page 115
Opioids
Opioids, also known as narcotic analgesics, are prescribed for severe pain, persistent cough, and diarrhea. The opioid class includes natural substances obtained from the unripe seeds of the poppy plant such as opium, morphine, and codeine. Synthetic drug examples are propoxyphene (Darvon), meperidine (Demerol), oxycodone (OxyContin), fentanyl (Duragesic, Sublimaze), methadone (Dolophine), and heroin. Vicodin (hydrocodone and acetaminophen combination) is one of the most widely abused of the narcotic drugs, most of which are analgesics. The therapeutic applications of the opioid analgesics are discussed in more detail in chapter 18 .
The effects of oral opioids begin within 30 minutes and may last over a day. Parenteral forms produce immediate effects, including the brief, intense rush of euphoria sought by heroin addicts. Individuals experience a range of CNS effects from extreme pleasure to slowed body activities and profound sedation. Signs include constricted pupils, an increase in the pain threshold, and, ultimately, respiratory depression. Overdose of opioids is extremely dangerous and fatal. The pharmacotherapy of opioid blocking drugs is covered in chapter 18 .
Addiction to opioids can occur rapidly, and withdrawal can produce intense symptoms. Although extremely unpleasant, withdrawal from opioids is not life threatening, compared to barbiturate withdrawal. Methadone is a narcotic sometimes used to treat opioid addiction. Although methadone has addictive properties of its own, it does not produce the same degree of euphoria as with other opioids, and its effects are longer lasting. Heroin addicts are switched to methadone to prevent unpleasant withdrawal symptoms. Because methadone is taken orally, patients are no longer exposed to serious risks associated with intravenous drug use, such as hepatitis and AIDS. Withdrawal from methadone is more prolonged than with heroin or morphine, but the symptoms are less intense. Patients sometimes remain on methadone maintenance for a lifetime. Other drugs used in the treatment of opioid dependence, including buprenorphine (Subutex) and naloxone, are discussed in chapter 18 .
Ethyl alcohol
Ethyl alcohol, commonly referred to as alcohol, is one of the most commonly abused drugs. Alcohol is a legal substance for adults, and it is readily available as beer, wine, and liquor. The economic, social, and health consequences of alcohol abuse are staggering. Despite the enormous negative consequences associated with long-term use, small quantities of alcohol consumed on a daily basis may have medical benefits such as the reduced risks of stroke and heart attack.
Alcohol is classified as a CNS depressant because it slows the region of the brain responsible for alertness and wakefulness. Alcohol easily crosses the blood-brain barrier, so its effects are observed within 5 to 30 minutes after consumption. Effects of alcohol are directly proportional to the amount consumed and include relaxation, sedation, memory impairment, loss of motor coordination, reduced judgment, and decreased inhibition. Alcohol also imparts a characteristic odor to the breath and increases blood flow in certain areas of the skin, causing a flushed face, pink cheeks, or red nose. Although these symptoms are easily recognized, the nurse must be aware that other substances and disorders may cause similar effects. For example, many antianxiety agents, sedatives, and antidepressants can cause drowsiness, memory difficulties, and loss of motor coordination. Certain mouthwashes contain alcohol and may cause the breath to smell like alcohol. Other disorders may produce breath smells that can be confused with alcohol. During assessment, the skilled nurse must consider these factors before confirming alcohol use.
The presence of food in the stomach slows the absorption of alcohol, thus delaying the onset of drug action. Metabolism, or detoxification of alcohol by the liver, occurs at a slow, constant rate, which is not affected by the presence of food. The average rate is about 15 mL per hour—the practical equivalent of one alcoholic beverage per hour. If consumed at a higher rate, alcohol will accumulate in the blood and produce greater depressant effects on the brain. Acute overdoses of alcohol produce vomiting, severe hypotension, respiratory failure, and coma. Death due to alcohol poisoning is not uncommon. The nurse should teach patients to never combine alcohol consumption with other CNS depressants because their effects are cumulative, and profound sedation or coma may result.
With acute alcohol withdrawal, benzodiazepines are the preferred drug class for treatment (Valium or Librium therapy). Although the use of benzodiazepines is more guarded for longer-term therapy of alcoholism, the reality is that many alcoholics continue to receive benzodiazepines for anxiety disorders and insomnia secondary to alcohol dependence. Seizures are also a risk to the patient, even after weeks of cessation from alcohol consumption; hence, benzodiazepine step-down therapy is often beneficial.
Chronic alcohol consumption produces both psychological and physiological dependence and results in a large number of adverse health effects. The organ most affected by chronic alcohol abuse is the liver. Alcoholism is a common cause of cirrhosis, a debilitating and often fatal failure of the liver to perform its vital functions. Liver impairment causes abnormalities in blood-clotting and nutritional deficiencies. It also sensitizes the patient to the effects of all medications metabolized by the liver. For alcoholic patients, the nurse should begin therapy with reduced medication doses until the adverse effects of pharmacotherapy can be assessed.
Delirium tremens (DT) may occur in individuals who have constantly consumed alcohol for a longer period. Symptoms are hallucinations, confusion, disorientation, and agitation. Many patients experience anxiety, panic, paranoia, and sensations of something crawling on the skin.
Alcohol withdrawal syndrome is severe and may be life threatening. Antiseizure medications may be used in the treatment of alcohol withdrawal (see chapter 15 ). Long-term treatment for alcohol abuse includes behavioral counseling and self-help groups such as Alcoholics Anonymous. Disulfiram (Antabuse) is another approach to discourage relapses. Disulfiram inhibits acetaldehyde dehydrogenase, the enzyme that metabolizes alcohol. If a patient consumes alcohol while taking disulfiram, he or she becomes violently ill within 5 to 10 minutes, with headache, shortness of breath, nausea/vomiting, and other unpleasant symptoms. Disulfiram is effective only in highly motivated patients, because the success of pharmacotherapy is entirely dependent on patient compliance. Alcohol sensitivity continues for up to 2 weeks after disulfiram has been discontinued. As a category X drug, disulfiram should never be taken during pregnancy.
[Complementary and Alternative Therapies: Milk Thistle for Alcohol Liver Damage]
In addition to disulfiram, acamprosate calcium (Campral) is an FDA-approved drug for maintaining alcohol abstinence in patients with alcohol dependence. Acamprosate’s mechanism of action involves the restoration of neuronal excitation—the alteration of gamma-aminobutyrate and glutamate activity in the CNS—and does not appear to have other CNS actions. Adverse reactions to acamprosate include diarrhea, flatulence, and nausea. The drug is contraindicated in patients with severe renal impairment but may be used in patients at increased risk for hepatotoxicity.
CANNABINOIDS page 113
Marijuana page 113
Introduction
Cannabinoids are substances obtained from the hemp plant Cannabis sativa, which thrives in tropical climates. Cannabinoid agents are usually smoked and include marijuana, hashish, and hash oil. Although more than 61 cannabinoid chemicals have been identified, the ingredient responsible for most of the psychoactive properties is delta-9-tetrahydrocannabinol (THC).
Marijuana
Marijuana, also known as grass, pot, weed, reefer, and many other names, is a natural product obtained from C. sativa. It is the most commonly used illicit drug in the United States. Use of marijuana slows motor activity, decreases coordination, and causes disconnected thoughts, feelings of paranoia, and euphoria. It increases thirst and craving for food, particularly chocolate and other candies. One hallmark symptom of marijuana use is red or bloodshot eyes, caused by dilation of blood vessels. THC accumulates in the reproductive organs.
When inhaled, marijuana produces effects that occur within minutes and last up to 24 hours. Because marijuana smoke is inhaled more deeply and held within the lungs for a longer time than cigarette smoke, marijuana smoke introduces four times more particulates (tar) into the lungs than tobacco smoke. Smoking marijuana on a daily basis may increase the risk of lung cancer and other respiratory disorders. Chronic use is associated with a lack of motivation in achieving or pursuing life goals.
Unlike many abused substances, marijuana produces little physical dependence or tolerance. Withdrawal symptoms are mild, if they are experienced at all. Metabolites of THC, however, remain in the body for months to years, allowing laboratory specialists to easily determine whether someone has taken marijuana. For several days after use, THC can also be detected in the urine. Despite numerous attempts to demonstrate therapeutic applications for marijuana, results have been controversial and the medical value of the drug remains to be proved. However, public support for legalization of marijuana has been increasing in recent years.
LSD
LSD
For nearly all drugs of abuse, predictable symptoms occur in every user. Effects from hallucinogens, however, are highly variable and dependent on the mood and expectations of the user and the surrounding environment in which the substance is used. Two people taking the same agent will report completely different symptoms, and the same person may report different symptoms with each use. Users who take LSD and psilocybin (magic mushrooms, or “shrooms”) ( Figure 11.1) may experience symptoms such
[Figure 11.1. The hallucinogen psilocyban, derived from mushrooms (left) produces similar effects in the human body as LSD (right)]
as laughter, visions, religious revelations, or deep personal insights. Common occurrences are hallucinations and afterimages projected onto people as they move. Users also report unusually bright lights and vivid colors. Some users hear voices; others report smells. Many experience a profound sense of truth and deep-directed thoughts. Unpleasant experiences can be terrifying and may include anxiety, panic attacks, confusion, severe depression, and paranoia.
LSD, also called acid, the beast, blotter acid, and California sunshine, is derived from a fungus that grows on rye and other grains. LSD is nearly always administered orally and can be manufactured in capsule, tablet, or liquid form. A common and inexpensive method for distributing LSD is to place drops of the drug on paper, often containing the images of cartoon characters or graphics related to drug culture. The paper is dried; users then ingest the paper containing the LSD to produce the drug’s effects.
LSD is distributed throughout the body immediately after use. Effects are experienced within an hour and may last from 6 to 12 hours. LSD affects the central and autonomic nervous systems, increasing blood pressure, elevating body temperature, dilating pupils, and increasing the heart rate. Repeated use may cause impaired memory and inability to reason. In extreme cases, patients may develop psychoses. One unusual adverse effect is flashbacks, in which the user experiences the effects of the drug again, sometimes weeks, months, or years after the drug was initially taken. Although tolerance is observed, little or no dependence occurs with the hallucinogens.
Other hallucinogens
Other Hallucinogens
In addition to LSD, other abused hallucinogens include the following:
- Mescaline. Found in the peyote cactus of Mexico and Central America ( Figure 11.2).
- MDMA (3,4-methylenedioxymethamphetamine; XTC or Ecstasy). An amphetamine originally synthesized for research purposes that has since become extremely popular among teens and young adults.
- DOM (2,5 dimethoxy-4-methylamphetamine). A recreational drug often linked with rave parties as a drug of choice having the name STP.
- MDA (3,4-methylenedioxyamphetamine). Called the love drug because it is believed to enhance sexual desires.
- Phencyclidine (PCP; angel dust or phenylcyclohexylpiperidine). Produces a trancelike state that may last for days and results in severe brain damage.
- Ketamine (date rape drug or special coke). Produces unconsciousness and amnesia; primary legal use is as an anesthetic.
Amphetamines and Methylphenidate
CNS stimulants have effects similar to those of the neurotransmitter norepinephrine (see chapter 13 ). Norepinephrine affects awareness and wakefulness by activating neurons in a part of the brain called the reticular formation. High doses of amphetamines give the user a feeling of self-confidence, euphoria, alertness, and empowerment; but just as short-term use induces favorable feelings, long-term use often results in feelings of restlessness, anxiety, and fits of rage, especially when the user is coming down from a “high” induced by the drug.
Most CNS stimulants affect cardiovascular and respiratory activity, resulting in increased blood pressure and increased respiration rate. Other symptoms include dilated pupils, sweating, and tremors. Overdoses of some stimulants lead to seizures and cardiac arrest.
Amphetamines and dextroamphetamines were once widely prescribed for depression, obesity, drowsiness, and congestion. In the 1960s, it became recognized that the medical uses of amphetamines did not outweigh their risk for misuse. Due to the development of safer medications, the current therapeutic uses of these drugs are extremely limited. Most substance abusers obtain these agents from illegal laboratories, which can easily produce amphetamines and make tremendous profits.
Dextroamphetamine (Dexedrine) may be prescribed for short-term weight loss, when all other attempts to reduce weight have been exhausted, and to treat narcolepsy. Methamphetamine, commonly called ice, is often used as a recreational drug by users who like the rush that it gives them. It usually is administered in powder or crystal form, but it may also be smoked. Methamphetamine is a Schedule II drug marketed under the trade name Desoxyn, although most abusers obtain it from illegal methamphetamine (meth) laboratories. A structural analogue of methamphetamine, methcathinone (street name, Cat), is made illegally and snorted, taken orally, or injected IV. Methcathinone is a Schedule I agent.
Methylphenidate (Ritalin) is a CNS stimulant widely prescribed for children diagnosed with attention deficit/hyperactivity disorder (ADHD). Adderall (dextroamphetamine and amphetamine combination) is another widely abused CNS used for the same therapeutic purpose. These drugs have a calming effect in children who are inattentive or hyperactive. By stimulating the alertness center in the brain, the child is able to focus on tasks for longer periods. This explains the paradoxical calming effects that these stimulants have on children, which is usually the opposite of that on adults. The therapeutic applications of methylphenidate and amphetamine combination drugs are discussed in chapter 16 .
Ritalin is a Schedule II drug that has many of the same effects as cocaine and amphetamines. It is sometimes abused by adolescents and adults seeking euphoria. Tablets are crushed and used intranasally or dissolved in liquid and injected IV. Ritalin is sometimes mixed with heroin, a combination called speedball. Adderall is the most widely abused amphetamine prescription drug.
Cocaine
Cocaine is a natural substance obtained from leaves of the coca plant, which grows in the Andes Mountains region of South America. Documentation suggests that the plant has been used by Andean cultures since 2500 B.C. Natives in this region chew the coca leaves, or make teas of the dried leaves. Because coca is taken orally, absorption is slow, and the leaves contain only 1% cocaine, so users do not suffer the ill effects caused by chemically pure extracts from the plant. In the Andean culture, use of coca leaves is not considered substance abuse because it is part of the social norms of that society.
Cocaine is a Schedule II drug that produces actions similar to those of the amphetamines, although its effects are usually more rapid and intense. It is the second most commonly abused illicit drug in the United States. Routes of administration include snorting, smoking, and injecting. In small doses, cocaine produces feelings of intense euphoria, a decrease in hunger, analgesia, illusions of physical strength, and increased sensory perception. Larger doses will magnify these effects and also cause rapid heartbeat, sweating, dilation of the pupils, and an elevated body temperature. After the feelings of euphoria diminish, the user is left with a sense of irritability, insomnia, depression, and extreme distrust. Some users report the sensation that insects are crawling under the skin. Users who snort cocaine develop a chronic runny nose, a crusty redness around the nostrils, and deterioration of the nasal cartilage. Overdose can result in dysrhythmias, convulsions, stroke, or death due to respiratory arrest. The withdrawal syndrome for amphetamines and cocaine is much less intense than from alcohol or barbiturate abuse.
Caffeine
Caffeine is a natural substance found in the seeds, leaves, or fruits of more than 63 plant species throughout the world. Significant amounts of caffeine are consumed in chocolate, coffee, tea, soft drinks, and ice cream. Caffeine is sometimes added to over-the-counter (OTC) pain relievers because it has been shown to increase the effectiveness of these medications. Caffeine travels to almost all parts of the body after ingestion, and several hours are needed for the body to metabolize and eliminate the drug. Caffeine has a pronounced diuretic effect.
Caffeine is considered a CNS stimulant because it produces increased mental alertness, restlessness, nervousness, irritability, and insomnia. The physical effects of caffeine include bronchodilation, increased blood pressure, increased production of stomach acid, and changes in blood glucose levels. Repeated use of caffeine may result in physical dependence and tolerance. Withdrawal symptoms include headaches, fatigue, depression, and impaired performance of daily activities.
Nicotine
Nicotine is sometimes considered a CNS stimulant, and although it does increase alertness, its actions and long-term consequences place it in a class by itself. Nicotine is unique among abused substances in that it is legal, strongly addictive, and highly carcinogenic. Furthermore, use of tobacco can cause harmful effects to those in the immediate area who breathe secondhand smoke. Patients often do not consider tobacco use as substance abuse.
Tobacco Use and Nicotine
The most common method by which nicotine enters the body is through the inhalation of cigarette, pipe, or cigar smoke. Tobacco smoke contains more than 1,000 chemicals, a significant number of which are carcinogens. The primary addictive substance present in cigarette smoke is nicotine. Effects of inhaled nicotine may last from 30 minutes to several hours.
Nicotine affects many body systems including the nervous, cardiovascular, and endocrine systems. Nicotine stimulates the CNS directly, causing increased alertness and ability to focus, feelings of relaxation, and light-headedness. The cardiovascular effects of nicotine include an accelerated heart rate and increased blood pressure, caused by activation of nicotinic receptors located throughout the autonomic nervous system (see chapter 13 ). These cardiovascular effects can be particularly serious in patients taking oral contraceptives: The risk of a fatal heart attack is five times greater in smokers than in nonsmokers. Muscular tremors may occur with moderate doses of nicotine, and convulsions may result from very high doses. Nicotine affects the endocrine system by increasing the basal metabolic rate, leading to weight loss. Nicotine also reduces appetite. Chronic smoking leads to bronchitis, emphysema, and lung cancer.
Both psychological and physical dependence occur relatively quickly with nicotine. Once started on tobacco, patients tend to continue their drug use for many years, despite overwhelming medical evidence that the quality of life will be adversely affected and their life span shortened. Discontinuation results in agitation, weight gain, anxiety, headache, and an extreme craving for the drug. Although nicotine replacement patches and gum assist patients in dealing with the unpleasant withdrawal symptoms, only 25% of patients who attempt to stop smoking remain tobacco-free a year later.
