chap4 - CHAPTER 4 DOWNERS: OPIATES/OPIOIDS &...

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Unformatted text preview: CHAPTER 4 DOWNERS: OPIATES/OPIOIDS & SEDATIVE-HYPNOTICS CHAPTER OVERVIEW Downers (depressants), which include opiates/opioids, sedative-hypnotics, and alcohol, depress the central nervous system. Effects range from sedation, pain relief, anxiety control, muscle relaxation, suppression of inhibitions, and drowsiness up to unconsciousness, coma, or death. They work by in- hibiting pain, stimulatory, and other neurotransmitters or by mimicking the body’s natural sedating neurotransmitters. The first part of this chapter surveys the different types of opiates and opioids (e. g., heroin, codeine, morphine, methadone, Dilaudid®), their history, effects, and side effects. The second part of the chapter examines the sedative—hypnotics (e.g., benzodiazepines, barbiturates), their effects, side effects, drug interactions, synergism, cross-dependence, and cross-tolerance. Alcohol is covered in Chapter 5. SHORT CHAPTER OUTLINE GENERAL CLASSIFICA- TION I. MAJOR DEPRESSAN T S A. OPIATES/OPIOIDS B. SEDATIVE-HYPNOTICS C. ALCOHOL (see Chapter 5) II. MINOR DEPRESSAN TS A. SKELETAL MUSCLE RELAXAN TS B. AN TIHISTAMINES C. OVER-THE-COUNTER DOWNERS D. LOOKALIKE DOWNERS OPIATES/OPIOIDS III. CLASSIFICA T ION A. OPIUM, OPIATES, & OPIOIDS IV. HISTORY OF USE (see Chapter 1) A. ORAL INGESTION B. SMOKING C. REF INEMENT OF MORPHINE, CODEINE, & HEROIN D. IV USE E. PATENT MEDICINES F. SNORTING G. TWENTIETH CENTURY H. HEROIN - A WORLD VIEW V. EFFECTS OF OPIOIDS A. PAIN B. PLEASURE C. FROM PLEASURE TO PAIN D. RECEPTOR SITES E. COUGH SUPPRESSION & DIARRHEA CONTROL VI. SIDE EFFECTS OF OPIOIDS A. PHYSICAL SIDE EFFECTS B. TOLERANCE, TISSUE DEPENDENCE, & WITHDRAWAL l . Tolerance 2. Tissue Dependence 3. Withdrawal VII. ADDITIONAL PROBLEMS WITH HEROIN & OTHER OPIOIDS A. NEONATAL EFFECTS B. OVERDOSE C. DIRTY & SHARED NEEDLES 1. Hepatitis C & HIV 2. Abscesses & Other Infections D. DILUTION & ADULTERATION E. COST F. POLYDRUG USE G. FROM EXPERIMENTATION TO ADDICTION l. The Vietnam Experience VIII. MORPHINE & OTHER OPIOIDS A. MORPHINE 1. Therapeutic Pain Control B. CODEINE C. HYDROCODONE (VICODIN®, HYCODAN®, TUSSENDQ, NORCO") D. METHADONE (DolophineQ) E. HYDROMORPHONE (Dilaudid®) F. OXYCODONE (0xyContin®, PercodanQ) G. MEPERIDINE (Demerolg, Pethidine‘”, Mepergan®) H. PENTAZOCINE (Talwin M“) 1. PROPOXYPHENE (Darvong Darvocet®, Propacet®, Wygesic®) J. FENTANYL (Sublimazeo) K. DESIGNER HEROIN L. LAAM (LEVOMETHADYL ACETATE) - M. NALOXONE (Narcan & NALTREXONE (Revia w N. BUPRENORPHINE D. TOLERANCE, TISSUE 2 [3H]-FURANONE (BUPRENEXQ, SUBUTEX", DEPENDENCE, & DIHYDRO) & BD (1,3 SUBOXONEQ) WITHDRAWAL BUTANEDIOL) O. CLONIDINE (Catapresg) l. Tolerance C. METHAQUALONE P_ ULTRARAPID OPIOID 2. Tissue Dependence (Quaalude®,Mandrax®) DETOXIFICATION 3. Withdrawal D. ZOLPIDEM (AmbienQ) E. BENZODIAZEPINE E. ETHCHLOVYNOL SEDATIVE-HYPNOTICS OVERDOSE (Placidylg’) F. MEMORY IMPAIRMENT & IX. CLASSIFICATION ROHYPNOLo OTHER pROBLEMS X HISTORY XI. USE, MISUSE, ABUSE, & ADDICTION XII. BENZODIAZEPINES EFFECTS XIII. BARBI T URA T ES TOLERANCE, TISSUE DEPENDENCE, & WITH DEPRESSANTS XV. DRUG INTERACTIONS A. SYNERGISM B. CROSS-TOLERANCE & A. MEDICAL USE OF WITHDRAWAL CROSS-DEPENDENCE BENZODIAZEPINES XIV. OTHER SEDA TIVE- XVI. MISUSE & DIVERSION B. NONMEDICAL USE or HypNoncs BENZODIAZEPINES A. GHB (GAMMA XVII. PRESCRIPTION DRUGS C. NEUROCHEMISTRY & HYDROXYBUTYRATE) & THE PHARMACEUTICAL GABA INDUSTRY B. GBL (GAMMA BUTYROLACTONE OR EXTENDED CHAPTER OUTLINE GENERAL CLASSIFICATION Downers induce sedation, muscle relaxation, drowsiness, and even coma by depressing the central nervous system. Downers work on more sites throughout the body than uppers (which gen- erally influence stimulatory neurochemicals). (p. 1 39) I. MAJOR DEPRESSAN T S A. Opiates/Opioids are used to treat acute pain, diarrhea, coughs, and a number of other ill- nesses. They are abused for their euphoric ef- fects, for physical and emotional pain relief, and for the suppression of withdrawal symp— toms. (p. 139) B. Sedative-hypnotics are synthesized drugs de- vised to treat anxiety and insomnia. All have toxic side effects and can cause tissue depend- ence. (p. 140) C. Alcohol, produced by fermentation of plant sugars or starches, is the oldest psychoactive drug in the world and the second most de- structive drug in terms of health consequences (after tobacco) and social consequences. (p. 140) II. MINOR DEPRESSAN T S A. Skeletal muscle relaxants are synthetically developed to depress areas of the brain respon- sible for muscle coordination and activity and are prescribed for muscle tension and pain. (p. 140) B. Antihistamines, synthetic drugs used to treat allergies, ulcers, shock, rashes, and even mo- tion sickness, produce drowsiness, block the release of histamine, and can induce depres- sion and drowsiness. They are occasionally abused for their depressant effects. (p. 140) C. Over-the-counter downers (e. g., Nytol®, Sominex®) are marketed as sleep aids and sedatives. (p. 140) D. Lookalike downers were products that looked like prescription downers. They were com- posed of legally available antihistamines. They are rarely found nowadays except in a few magazine ads for legal downers. (p. 140) OPIATES/OPIOIDS Opiates/opioids are some of the oldest and best- documented psychoactive drugs. Since the 1970s the discovery of the body’s own natural painkill- ers, endorphins and enkephalins, significantly 29 changed researchers’ and scientists’ understanding of opiates/opioids as well as the whole field of addictionology. (p. 140) III. CLASSIFICATION Opium is processed from the milky fluid of the opium poppy plant that is processed to morphine, codeine, and thebaine. Semisynthetic opiates in- clude heroin and many prescription painkillers like Vicodin®, OxyContin®, Percodan® and Dilau- did®. Fully synthetic opiate—like drugs include Demerol®, Darvon®, and methadone. Opiate an- tagonists that block the effects of opiates and opi- oids include naloxone and naltrexone. (p. 141) IV. HISTORY OF USE (see Chapter 1) Opium was used by the ancient Sumerians, Egyp- tians, and Chinese as a medicine, pleasure- inducing substance, and poison. Different meth- ods of use, new refinements of the drugs, synthe- sis of molecules that act like natural opiates, and time-release versions of these drugs have slowly increased not only the benefits of the substances but also their potential for abuse. (p. 141) A. Oral ingestion. Opium was originally chewed, eaten, or drunk in various liquids al— though its bitter taste limited its addiction po- tential. It was used through the Middle Ages and beyond in medications such as laudanum and paregoric. (p. 142) B. Smoking opium increased nonmedical use, increased the intensity of the effects, and mul- tiplied its abuse potential. It was actively pro- moted by the British in China and introduced to the United States by Chinese immigrants. (p. 143) C. Refinement of morphine, codeine, & heroin. In 1805 Frederick Sertumer refined morphine from opium, increasing its strength by a factor of 10. Codeine, only one-fifth the strength of morphine, was used in cough syrups and patent medicines. Heroin was refined from morphine in 1874. (p. 143) D. IV use began in 1853 with the invention of the hypodermic needle when morphine, and later heroin, began to be injected thus increasing the intensity and addictive potential especially with heroin. (p. 144) E. Patent medicines. By the middle of the 1800s opiates were used in tonics and patent medi- cines. Opium also became a fashionable drug. 30 Iatrogenic (physician-induced) addiction was a common problem. (p. 144) F. Snorting was a popular method of taking her- oin, especially among those afraid of needles. More than half of all heroin addicts entering treatment began their heroin use by insufflation. (p. 144) G. Twentieth century. Casual nonmedical use of opiates was declared illegal at the beginning of the twentieth century by the international community through The Hague Resolutions and by the United States through the Pure Food and Drug Act in 1906 and the Harrison Narcotics Act in 1914. Illegal sources sprang up and legal prescription opiates began to be diverted into illegal markets. Currently an es- timated 3.5 million Americans use prescription opiates/opioids illicitly every month compared to 120,000 to 800,000 heroin abusers. (p. 144) H. Heroin — a world view. There are 5—10 mil- lion regular heroin users worldwide however the United States consumes only 3% of the world’s heroin supply. In the United States most heroin comes from Mexico and Canada. In the 1990s Afghanistan grew more than 70% of the world’s supply. The heroin that comes from the Golden Triangle is called “China white” and can be up to 99% pure. In the 1980s a new form of heroin from Mexico called “tar” or “black tar” took over a large part of the market in the western United States. It is 40—80% pure. In the early 1990s a number of Colombian cocaine cartels diversified and started to grow and distribute opium/heroin. (p. 145) V. EFFECTS OF OPIOIDS Opioids are prescribed legally to control pain, coughing, and diarrhea. They are used illegally to induce a rush and euphoria, to control emotional pain, and to avoid withdrawal symptoms. (p. 147) A. Pain. Opioids prevent the transmission of substance “P,” the neurotransmitter that trans- mits pain. They also block most of what does get through to the receiving neuron. Painkilling effects of the various opioids are similar, in- cluding lowered anxiety, serenity, drowsiness, and deadening of unwanted emotions. The variables are the strength and toxicity of the drug and the duration of use. (p. 147) B. Pleasure. Opioids artificially activate the re- ward/reinforcement center by slotting into re- ceptor sites meant for endorphins. Heroin has the strongest effect of any of the opioids on the reward pathway. Powerful psychoactive drugs, including heroin, disrupt the cut-off switch in the brain that says “that’s enough,” thereby reinforcing the desire to continue using. (p. 148) C. From pleasure to pain. The area of the brain that signals pleasure/reward is the same area that signals alleviation of pain. Therefore the rush or pain alleviation is understood by the brain to be good for the body. This reinforces abusers to continue using past the point of pain relief while nonabusers stop at pain relief. An- other cause of continued use in addicts is the relief from the pain of withdrawal. (p. 149) D. Receptor sites. There are multiple natural opioid receptor sites for the body’s endoge— nous opioids. Opioid drugs slot into these same receptors with each opioid drug having a unique affinity for each kind of opioid receptor site. (p. 149) E. Cough suppression & diarrhea control. Opioids suppress coughs by controlling the cough center in the brainstem. They control di- arrhea by inhibiting gastric secretions and de- pressing intestinal muscles. (p. 149) VI. SIDE EFFECTS OF OPIOIDS A. Physical effects are felt in almost every part of the body. Some effects are noticeable, like drooping eyelids, nodding, and slurred slowed speech. Other effects are less visible, like sup- pression of the cough center. More severe ef- fects are felt in the digestive and hormonal systems. Even when used for legitimate medi- cal treatments, undesired effects occur includ- ing nausea or constipation. (p. 149) B. Tolerance, tissue dependence, and with- drawal. The desire for relief from pain and the experiencing of pleasure combined with tolerance, tissue dependence, and withdrawal are the main reasons for the addictive nature of opioids. (p. 150) 1. Tolerance occurs when the body tries to neutralize the heroin by a variety of meth- ods. These include speeding up metabo- lism, desensitizing nerve cells, excreting the drug more rapidly, and altering the brain and body chemistry to compensate for the effects of the drug. Tolerance develops at different rates for different body systems and there is almost no 'limit to the develop- ment of opioid tolerance. (p. 150) 2. Tissue dependence means that adaptation to effects of a drug can alter brain chemis- try temporarily and sometimes perma- nently. Then the body relies on the drug to stay normal since cessation of use causes severe withdrawal symptoms. Tolerance and physical dependence can extend to other opioids. (p. 151) 3. Withdrawal. Acute withdrawal occurs when 2—3 weeks of continuous use are fol- lowed by abstinence. Protracted withdrawal can last for months after abstinence has be- gun. Short-acting opioids, like heroin and morphine, cause more severe acute with- drawal symptoms. Long-acting opioids, like methadone, delay the onset of withdrawal and the acute withdrawal symptoms are milder but last for weeks. (p. 151) VII. ADDITIONAL PROBLEMS WITH HER OIN & OTHER 0P1 OIDS A. Neonatal effects occur because opioids cross the placental barrier. Problems include greater risk of miscarriage, placental separation, pre- mature labor, stillbirth, and seizures. A baby born to an addicted mother is also addicted and withdrawal for the infant can be quite severe, even fatal. (p. 152) B. Overdose in older users can be fatal. Severe respiratory depression is the major cause of death with heroin overdose. Heroin overdose can be countered by an opioid antagonist (e.g., Narcan®), although it obliterates the high and will cause severe withdrawal effects if the overdose victim is an addict. (p. 152) C. Dirty & shared needles constitute one of the greatest dangers of drug use since large, po- tentially fatal doses can enter the bloodstream and the risk of adulteration of the drug is high. Bacteria and viral infection, including the HIV virus that causes AIDS, can be transmitted by dirty hypodermic needles. (p. 152) 1. Hepatitis C & HIV. From 50% to 90% of all needle-using heroin addicts carry the hepatitis C virus. In addition 25% of all US. AIDS cases were transmitted to an IV drug user by a contaminated needle. Over 10% of AIDS cases were transmitted to sex partners of IV drug users through sexual contact while 70% of children infected with 31 HIV had mothers who were IV drug users or had sexual contact with IV drug users. (p. 153) 2. Abscesses and other infections in soft tis- sue are common among intravenous drug users. One of the worst infections is necro- tizing fasciitis, an infection that destroys fascia and subcutaneous tissue but is not immediately visible on the surface. Endo- carditis, an infection of heart valves, is found more often in IV drug users. Cotton fever is an illness of IV drug users caused by endotoxins that thrive in the cotton that is used to prepare the drug injection. (p. 153) D. Dilution & adulteration. Street drugs can vary radically in purity and be adulterated with a variety of potentially dangerous chemicals and substances. . Cost. Heroin addiction is expensive, costing from $20 to $200 per day depending on the level of use. About 60% of the cost to support a habit is gotten through consensual crime in- cluding prostitution and drug dealing. Contrary to popular perception, 73% of heroin users are gainfully employed. (p. 150) . Polydrug use. Multiple drug use can occur when an addict uses different drugs for differ- ent reasons: heroin in the morning to stop withdrawal symptoms, speed to get energetic, and marijuana in the evening to relax. Mixing drugs occurs when someone combines opioids with other drugs, such as cocaine or ampheta- mine with morphine or heroin to enhance the euphoric or painkilling effects of either drug. Morphing refers to the use of multiple drugs to counter the effects of the original drug, such as stimulants to counter the depressant effects of heroin or alcohol to come down from stimulant use. Cycling means giving up a drug for several weeks to help the body lower its tolerance to the effects of the drug and lower the cost of the addiction. Sometimes substitute drugs are used during the rest period. Sequen- tialing means using one drug then moving on to another drug. (p. 154.) . From experimentation to addiction. Ex- perimentation with alcohol, marijuana, and to- bacco begins much earlier than experimenta- tion with heroin. It takes an average of 1 year of sporadic heroin use for someone to develop a daily habit. Over time the pain relief offered by heroin use becomes greater than the pleas- ure. Treatment is a physiological as well as a psychological process. The addict needs to be detoxified from all opioids, often with the use of agonist medications. Some heroin addicts need to remain on agonist therapy (e.g., LAAM, methadone, buprenorphine) for an extended length of time to prevent relapse due to the addict’s intense desire to avoid experi- encing withdrawal symptoms. (p. 155) l. The Vietnam experience suggests that even though tissue dependence caused by use of drugs can be a powerfill basis for addiction, heredity and environment of returnees seemed to have an even greater influence on whether they remained addicted. (p. 155) VIII. MORPHINE & OTHER OPIOIDS A. Morphine is refined from opium and is the standard by which effective pain relief is measured. Different routes of administration have different effects. The liver is the principle site of metabolism. It converts the morphine into metabolites that more readily cross the blood-brain barrier and possibly are more po- tent than the morphine itself. Morphine can be detected in the urine for several days. (p. 156) 1. Therapeutic pain control. Severity of pain is a subjective judgment made by the pa- tient. Physicians and nurses ask the patient to self-rate pain and then partly base the prescription on this rating. The concerns are fear that addiction might develop, that the opioid will mask clues to a serious disease, and that the patient may be faking symp- toms in order to get the drugs to supply a habit. American Society of Addiction Medicine (ASAM) guidelines issued in 1997 recommend that physicians use more of their own judgment in prescribing opi- oids and that they should not be held re- sponsible if the patient cons them into pre- scribing more drugs. Most of the problems with moderate-strength opioids come from long-term use. The patient becomes more sensitive to pain because the body produces fewer of its own painkillers and down regulates its own opioid receptors. (p. 156) B. Codeine is extracted directly from opium or refined from morphine. It is an analgesic and is commonly used to control severe coughs. Co- deine used to be the most widely prescribed and abused prescription opioid in the United States but hydrocodone (Vicodin®) now has that dubious honor. The half-life of codeine is about 3 hours and it is detectable in urine for up to 2 or 3 days. (p. 157) . Hydrocodone (Vicodin®, Hycodan®, Tus- send®, Norco®) is the most prescribed opioid. It has many of the same actions as codeine but produces less nausea. (p. 158) . Methadone (Dolophine®) is a long-lasting synthetic opioid that is taken orally to control heroin addiction. There are approximately 200,000 heroin addicts involved in methadone treatment in more than 950 methadone mainte- nance treatment programs nationwide. Metha- done reduces drug craving and blocks with- drawal symptoms for 24—72 hours. The drug can itself be abused and is addicting. (p. 158) . Hydromorphone (Dilaudid®), a short-acting, semisynthetic opioid, is prescribed as an alter- native to morphine for moderate-to-severe pain. It is 7—10 times more potent on a gram- for-gram basis than morphine. On the street, illegally diverted Dilaudid® is mixed with co- caine or methamphetamine to make a speed- ball. (p. 158) . Oxycodone (OxyContinQ, Percodan®) is much stronger than codeine but weaker than either morphine or Dilaudid®. OxyContin® is a time-release version of the drug. When crushed, the time-release effect is destroyed consequently rendering the drug more potent that many say creates an effect similar to her- oin. (p. 159) . Meperidine (Demerol®, Pethidine®, Meper- gan®), one of the most widely used analgesics, is only one-sixth the strength of morphine. It is often the opioid most often abused by medical professionals. (p. 159) . Pentazocine (Talwin NX®) acts as a weak opioid antagonist as well as an opioid agonist. When combined with an antihistamine drug and then injected (“Ts & blues”), it gives a heroin-like high. (p. 159) . Propoxyphene (Darvon®, Darvocet®, Pro- pacet®, Wygesic®) is prescribed for mild-to- moderate pain and lasts for 4—6 hours. It can be used in the detoxification of heroin addicts. (p. 159) J. Fentanyl (Sublimaze®) is the most powerful of the opioids (50—100 times as strong as mor- phine) and is used after surgery for severe pain. (p. 159) K. Designer heroin includes street versions of fentanyl, known as “China white.” These drugs are made without controls and can be very dangerous since they can be from 100 to 20,000 times stronger than regular heroin and they can contain MPTP that destroys dopa- mine—producing brain cells. This is what causes the condition called “frozen addict.” (p. 160) L. LAAM (levomethadyl acetate) is a long- acting opioid used for heroin replacement ther- apy. It is unsuitable for pain management. (p. 1 60) M.Nalox0ne (Narcan®) & Naltrexone (Revia®) are opioid antagonists that block the effects of opioids. Narcan® is effective in treating heroin or opioid overdoses. Revia® is used to prevent relapse and help break the cycle of addiction for opioids. Furthermore Revia® is used to re- duce craving for alcohol and cocaine and is sometimes used in recovery from addiction to those drugs. (p. 161) N. Buprenorphine (Buprenex®, Subutex®, Sub- oxone®) is a powerful opioid agonist at low doses and an opioid antagonist at high doses. It has been approved as an alternative to metha- done for detoxification and induction of methadone maintenance. It has a relatively high degree of safety. Buprenorphine may now be prescribed by physicians in their offices rather than only at a drug treatment clinic. (p. 161) O. Clonidine (Catapres®), a nonopioid, was originally prescribed for the treatment of hy- pertension. It is now used to diminish opioid withdrawal symptoms. (p. 161) P. Ultrarapid opioid detoxification is a medi- cally supervised rapid detoxification that takes place while the addict is under general anes- thesia. There is much controversy regarding this process. (p. 161) SEDATIVE-HYPNOTICS IX. CLASSIF I CA TI 0N More than 60 million prescriptions were written for sedative-hypnotics in 2001. However, psychi- 33 atric medications for depression have taken over a significant part of sedative-hypnotics’ share of the market. The two main groups of sedative- hypnotics are benzodiazepines and barbiturates. The effects of sedative-hypnotics are similar to the effects of alcohol. Sedatives are calming drugs while hypnotics are sleep inducers. (p. 161) X. HISTORY Calming and sleep-inducing drugs have been around for millennia. They include bromides, in- troduced in the 1850s and used as sedatives or an- ticonvulsants; chloral hydrate, used as a sedative and hypnotic; paraldehyde, used to control alco- hol withdrawal; barbiturates, popular in the 1930s and 1940s, but having a low margin of safety; meprobamate (Miltown®), developed in the ’40s and ‘50s that replaced barbiturates and were known as “mother’s little helper”; gluteth- imide (Doriden®), an unsatisfactory substitute for barbiturates; and benzodiazepines, discovered in 1957 and less toxic than barbiturates. Benzodia- zepines today dominate the market for sedative- hypnotics. Though they are less toxic than other sedatives, they can be addictive and have danger- ous withdrawal symptoms. (p. 163) XI. USE, MISUSE, ABUSE, & ADDICTION Attitudes about these drugs have vacillated be- tween confidence in their effects and dissatisfac- tion with issues of over—prescription and misuse. These drugs aid in the treatment of many psycho- logical and physical conditions. Misused, they can cause undesirable side effects, dependence, abuse, addiction, and even death (p. 164) XII. BENZ ODIAZEPINES Developed in the ’40s and ’50s as an alternative to barbiturates, benzodiazepines are the most widely used sedative-hypnotics. Current recommenda- tions are that, because of the severity of with- drawal effects, these drugs should be used only short term and for specific conditions. (p. 165) A. Medical use of benzodiazepines. Benzodia- zepines are used as antianxiety drugs, as sleep aids, as sedatives, and as drugs to control sei- zures. Consequently they are prescribed for panic attacks, insomnia, for skeletal muscle spasms, to control seizures, or as an anesthetic for surgery. (p. 165) 34 B. Nonmedical use of benzodiazepines include motives similar to use of alcohol. These drugs are often abused with other drugs, for instance to come down from methamphetamine and co- caine highs, as substitutes for heroin, and to prevent alcohol withdrawal symptoms. Benzo- diazepine abusers are more likely to be older than 30 years of age, White, well-educated, and female. (p. 166) C. Neurochemistry & GABA. GABA is the most important inhibitory neurotransmitter. Benzodiazepines potentiate GABA and are then converted by the liver into metabolites as active or more active than the original drug (prodrugs). (p. 166) D. Tolerance, tissue dependence, & withdrawal 1. Tolerance to benzodiazepines develops as the liver become more efficient in process- ing the drug. A younger person can tolerate higher doses than someone older. (p. 167) 2. Tissue dependence. Addiction develops when 10—20 times the normal dosage is taken for several months or low doses (therapeutic doses) are taken for a year or more. (p. 167) 3. Withdrawal can be severe, sometimes in- volving seizures, convulsions, and even death. It can take several months to taper from the drug and allow the body to return to normal. The withdrawal symptoms can come erratically and go in cycles separated by 2—10 days. These symptoms may persist for several months after cessation of drug use (protracted withdrawal). (p. 167) E. Benzodiazepine overdose. It takes 700 times the therapeutic dose of benzodiazepines to be lethal. This margin of safety is greatly dimin- ished when they are taken in combination with alcohol. Symptoms of overdose include drowsiness, loss of consciousness, depressed breathing, coma, and death if left untreated. (p. 168) F. Memory impairment, Rohypnol®. The amne- sic effect of benzodiazepines (medically known as retrograde and anterograde amnesia — com- monly known as black outs or brown outs) has been used by some men to sexually molest women. Rohypnol® has become known as the “date rape drug” along with GHB. In 1996 R0- hypnol® was banned in the United States, and use of it to sexually assault someone or commit violence adds 20 more years to the sentence. (p. 168) XIII. BARBI TURA T ES Since barbital was developed in 1903 and then phenobarbital in 1913, barbiturates have come to include more than 2,000 different compounds, 50 that are marketed. (p. 168) A. Effects. There are long-acting, intermedi- ate-acting, short-acting, and very short- acting barbiturates. They induce a feeling of disinhibitory euphoria, similar to alco- hol. The effects often depend on the mood of the user and the setting where taken. B. Tolerance, Tissue Dependence, & Withdrawal. Tolerance develops in a va- riety of ways. Dispositional tolerance in- creases the efficiency of the metabolism of the drug. Pharmacodynamic tolerance reduces nerve cell and tissue sensitivity to the drug. Tissue dependence occurs when 8—10 times the normal dosage is taken daily for 30 days or more. Withdrawal symptoms develop upon cessation of use: anxiety, agitation, loss of appetite, nausea, vomiting, increased heart rate, excessive sweating, abdominal cramps, and tremu- lousness. Withdrawal symptoms resulting from heavy tissue dependence are very dangerous and can result in convulsions within 12 hours to 1 week from the last dose. (p. 169) XIV. OTHER SEDA TI VE-H YPNOTICS A. GHB (gammahydroxybutyrate), popular among bodybuilders, has an effect similar to methaqualone or alcohol intoxication. It is popular in rave clubs, and has been used as a date rape drug. (p. 169) B. GBL (gamma butyrolactone or 2[3H]- fluranone dihydro) and BD (1,3,butanediol) are prodrugs, meaning they are metabolized to GHB in the body. They also are an ingredient in paint strippers. (p. 170) C.Methaqualone (Quaaludes®, Mandrax®) was withdrawn from the legitimate market in 1984, though counterfeit versions are on the street. The drug is sought for its overall sedative ef- fect and mild euphoria. (p. 170) D. Zolpidem (Ambien®) is a short-acting hyp— notic that has a lower addiction risk than most benzodiazepines and is prescribed for sleep disorders. It can cause memory, performance, and learning impairment. (p. 170) E. Ethchlorvynol (Placidyl®) is an older seda- tive-hypnotic called “green weenies” on the street. It is about the equivalent to Doriden® in potency with similar toxic and addictive ef- fects but shorter acting. (p. 171) OTHER PROBLEMS WITH DEPRESSANTS XV. DRUG INTERACTIONS A. Synergism occurs when the combined effects of different drugs are greater than the individ- ual effects. Drug synergism results in 4,000 deaths and 50,000 emergency room visits per year. (p. 171) B. Cross-tolerance & cross-dependence. Cross- tolerance is the development of tolerance to other drugs because of exposure to the initial drug, possibly because many drugs are me- tabolized by the same enzymes. Cross- dependence occurs when addiction to one drug increases liability to addiction to other drugs in the same chemical family. (p. 171) XVI. MISUSE AND DI VERSION Misuse and diversion result from poor practices by some medical professionals, by patients re- ceiving drugs from a number of different physi- cians, through forged or altered prescriptions, and from smuggling. Laws requiring triplicate pre— scriptions for opioids are an attempt to curtail misuse and diversion. XVII. PRESCRIPTION DRUGS & THE PHARMA CE U T ICAL IND UST R Y In 2002 Americans spent about $145.5 billion or about 9% of total medical expenditures on pre- scription medications. Legal psychoactive drugs, including psychiatric medications, account for ap- proximately 10—12% of prescriptions written in the United States. In contrast to the $145.5 billion spent on prescription drugs, $60—$65 billion was spent on illegal drugs, $70—$80 billion on to- bacco, and $140—$150 billion on alcohol. (p. 172) 35 36 DISCUSSION TOPICS . Compare the use of legally prescribed heroin vs. the use of methadone to treat opioid addic— tion. Discuss it from crime prevention, ethical, and recovery points of view. Ask students to examine and describe their physical sensations when they have hurt them- selves, paying particular attention to the sensa- tions of lessening of pain and a slight euphoria because of the release of natural endorphins. Compare Valium® addiction to heroin addic- tion, physically, mentally, financially, and criminally. Then discuss which is worse, with- drawal from heroin or withdrawal from Val- ium®. Discuss the subjective nature of pain and the fact that different people need different amounts of painkillers, or even none at all, for the same injury. Discuss which drugs are likely to be prescribed or recommended for the following complaints, what the benefits and drawbacks might be, and what nondrug therapies might be used instead. For example a. “I can‘t sleep at night.” b. “Since my spouse died, I feel low all the time.” c. “These headaches are killing me.” d. “I like to reward myself.” 4. CRITICAL THINKING AND CLASS EXERCISES . Have a group of students either dramatize or create a three-dimensional model of a synapse with a secondary terminal. Then have them show first how pain is transmitted and then how opioids block the transmission of pain signals. As the students to compare the descriptions of several regularly prescribed sedatives (Xanax®, Valium®, etc.) in the Physicians ’ Desk Refer— ence with advertisements for those drugs in professional medical journals. How are the ads designed to encourage physicians to prescribe the drugs? How are patients portrayed in the ads? What characteristics of the drugs are not emphasized in the ads? . Many more benzodiazepines (e.g., Valium®, Xanax®) are prescribed for women than for men. Ask students to how they can account for the disparity. Invite a pharmacist or emergency room physi- cian to come to class to discuss his or her ex- periences with drug addicts trying to “put something over” on him or her. Also have the visitor talk about the use and abuse of over- the-counter drugs. ...
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This note was uploaded on 04/13/2008 for the course BIO 1033 taught by Professor Joel.martinez,jr.,ph.d. during the Fall '04 term at The University of Texas at San Antonio- San Antonio.

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chap4 - CHAPTER 4 DOWNERS: OPIATES/OPIOIDS &...

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