DRUG ABUSE

the excessive, maladaptive, or addictive use of drugs for nonmedical purposes despite social, psychological, and physical problems that may arise from such use. Abused substances include such agents as anabolic steroids, which are used by some athletes to accelerate muscular development and increase strength and which can cause heart disease, liver damage, and other physical problems; and psychotropic agents, substances that affect the user's mental state and are used to produce changes in mood, feeling, and perception. The latter category, which has a much longer history of abuse, includes opium (and such derivatives as heroin), hallucinogens, barbiturates, cocaine, amphetamines, tranquilizers, the several forms of cannabis, and alcohol. See also steroid. The history of nonmedical drug consumption is ancient. The discovery of the mood-altering qualities of fermented fruits and substances such as opium has led to their use and, often, acceptance into society. Just as alcohol has a recognized social place in the West, so many other psychotropics have been accepted in different societies. The major problem that arises from the consumption of psychotropic drugs is dependence, the compulsion to use the drug despite any deterioration in health, work, or social activities. Dependence varies from drug to drug in its extent and effect; it can be physical or psychological or both. Physical dependence becomes apparent only when the drug intake is decreased or stopped and an involuntary illness called the withdrawal (or abstinence) syndrome occurs. Drugs known to produce physical dependence are the opiates (i.e., opium and its derivatives) and central-nervous-system depressants such as barbiturates and alcohol. Psychological dependence is indicated when the user relies on a drug to produce a feeling of well-being. This type of dependence varies widely with both substance and user. In its most intense form the user becomes obsessed with the drug and focuses virtually all his interest and activity on obtaining and using it. Another related phenomenon is tolerance, a gradual decrease in the effect of a certain dose as the drug is repeatedly taken; increasingly larger doses are needed to produce the desired effect. Tolerance does not always develop. It is most marked with habitual opiate users. The term addiction is often used synonymously with dependence but should probably be reserved for drugs known to cause physical dependence. Other hazards of drug abuse include general risks, such as the danger of infection by the AIDS virus and other diseases that can be communicated by use of nonsterile needles or syringes when drugs are taken by injection. Some hazards are associated with the specific effects of the particular drugparanoia with high doses of stimulants, for example. In addition, adverse social effects stemming from drug abuse are numerous. Heroin, an opiate that is not used medically in the United States, is one of the drugs most associated with abuse and addiction in the eyes of the public. In general, opiates are called narcotics because they are used medically to relieve pain and produce sleep. Other opiates that have been abused are opium, morphine, pethidine, codeine, dipipanone, and methadone. Methadone is often used in substitution therapy as a less-addictive opiate that, theoretically at least, can be used to wean the user off heroin and eventually off opiates altogether. Drugs that either depress or stimulate the central nervous system have long been used for nonmedical reasons. Depressants include all sedatives and hypnotics such as barbiturates and benzodiazepines (minor tranquilizers). These are usually taken by mouth but can be injected. The main stimulants are amphetamines or their derivatives and cocaine, a natural component of the leaves of the coca plant. Amphetamines can be taken by mouth or injected; cocaine is either injected or inhaled through the nose. One form of cocaine (freebase, or crack) is generally smoked. Other drugs that are frequently abused include cannabis (marijuana, hashish, etc., from the hemp plant Cannabis sativa), PCP, and such hallucinogens, or psychedelics, as LSD and mescaline. The purchase, sale, and nonmedical consumption of all the aforementioned drugs are illegal, and these psychotropic drugs can be obtained only on the black market. However, this is not the only route to drug abuse. Alcohol, for instance, can be legally purchased throughout much of the world, despite its high potential for abuse. Also, dependence on prescribed drugs is not uncommon, especially with tranquilizers and hypnotics. What was once a serious social problem of dependence on prescribed barbiturates has been overtaken largely by the widespread use of benzodiazepine tranquilizers such as diazepam (Valium) and chlordiazepoxide (Librium). Millions of legal prescriptions for these drugs are issued every year. Problems relating to drug abuse can also occur with substances not normally thought of as drugs. Solvent abuse, commonly known as glue-sniffing, is a growing problem, especially among teenagers and even younger children. The inhalation of volatile solvents produces temporary euphoria but can lead to death by respiratory depression, asphyxiation, or other causes. Additional reading General works Victor A. Drill, Drill's Pharmacology in Medicine, 4th ed., edited by Joseph R. DiPalma (1971); and J.H. Gaddum, Gaddum's Pharmacology, 9th ed., edited by A.S.V. Burgen and J.F. Mitchell (1985), both classic texts; Goodman & Gilman's The Pharmacological Basis of Therapeutics, 9th ed. by Joel G. Hardman and Lee E. Limbird (1996), a comprehensive source with an emphasis on the clinical applications of drugs; Avram Goldstein, Lewis Aronow, and Sumner M. Kalman, Principles of Drug Action: The Basis of Pharmacology, 2nd ed. (1973), broad and detailed coverage of the physiological effects of drugs; Jack R. Cooper, Floyd E. Bloom, and Robert H. Roth, The Biochemical Basis of Neuropharmacology, 5th ed. (1986), an introduction to many aspects of neuropharmacology; W.C. Bowman and M.J. Rand, Textbook of Pharmacology, 2nd ed. (1980), a comprehensive treatment of the physiological and biochemical processes underlying pharmacological mechanisms; H.O. Schild, Applied Pharmacology, 12th ed. (1980), an introduction; Charles R. Craig and Robert E. Stitzel (eds.), Modern Pharmacology, 2nd ed. (1986); and Andres Goth, Medical Pharmacology: Principles and Concepts, 11th ed. (1984). The basis of drug action is studied in William C. Holland, Richard L. Klein, and Arthur H. Briggs, Introduction to Molecular Pharmacology (1964); and E.J. Arins (ed.), Molecular Pharmacology: The Mode of Action of Biologically Active Compounds, 2 vol. (1964). Mechanisms of drug action are examined in John W. Lamble (ed.), Towards Understanding Receptors (1981), More About Receptors (1982), and John W. Lamble and Alison C. Abbott (eds.), Receptors, Again (1984), collections of articles from pharmacological journals. Effects of drugs on the body are studied in Stephen H. Curry, Drug Disposition and Pharmacokinetics, 3rd ed. (1980); John W. Lamble (ed.), Drug Metabolism and Distribution (1983); and Milo Gibaldi and Laurie Prescott (eds.), Handbook of Clinical Pharmacokinetics (1983). Types of drugs: autonomic nervous system pharmacology Michael D. Day, Autonomic Pharmacology: Experimental and Clinical Aspects (1979), a general text; and Stanley Kalsner (ed.), Trends in Autonomic Pharmacology, 2 vol. (197982), a collective study. (Central nervous system pharmacology): W.D. Wylie, Wylie and Churchill-Davidson's A Practice of Anaesthesia, 5th ed., edited by H.C. Churchill-Davidson (1984), a comprehensive reference source; Thomas E. Keys, The History of Surgical Anesthesia, rev. ed. (1963, reprinted 1978), an authoritative account; and John Adriani, Labat's Regional Anesthesia: Techniques and Clinical Applications, 4th ed. (1985), a comprehensive, well-illustrated text. Other studies of physiological mechanisms and applications of anesthetics include Robert D. Dripps, James E. Eckenhoff, and Leroy D. Vandam, Introduction to Anesthesia: The Principles of Safe Practice, 6th ed. (1982); and Rudolph H. De Jong, Local Anesthetics, 2nd ed. (1977). Analgesics and narcotics are treated in John J. Bonica (ed.), Pain (1980), an examination of the body systems involved in pain and of the physiological, psychological, and clinical aspects of therapy. Drugs that affect mood and behaviour are the subject of Jack D. Barchas et al. (eds.), Psychopharmacology: From Theory to Practice (1977), an introductory text with detailed examples of treatment protocols and problems; Morris A. Lipton, Alberto DiMascio, and Keith F. Killam (eds.), Psychopharmacology: A Generation of Progress (1978), a general historical analysis; S.J. Enna, Jeffrey B. Malick, and Elliott Richelson (eds.), Antidepressants: Neurochemical, Behavioral, and Clinical Perspectives (1981), a symposium of papers by leading practitioners; F. Neil Johnson (ed.), Handbook of Lithium Therapy (1980), an analysis of the therapeutic use of lithium in the treatment of mental disorders; and Judith P. Swazey, Chlorpromazine in Psychiatry: A Study of Therapeutic Innovation (1974), a historical study. Sedatives are analyzed in D.J. Greenblatt, R.I. Shader, and D.R. Abernethy, Drug Therapy: Current Status of Benzodiazepins, The New England Journal of Medicine, 309(6):354358 (Aug. 11, 1983) and 309(7):410416 (Aug. 18, 1983). Applications of antiepileptic drugs are the topic of Gail E. Solomon, Henn Kutt, and Fred Plum, Clinical Management of Seizures: A Guide for the Physician, 2nd ed. (1983); and H.-H. Frey and D. Janz (eds.), Antiepileptic Drugs (1985). Cardiovascular system pharmacology R. Douglas Wilkerson (ed.), Cardiac Pharmacology (1981), an overview of the drug therapy and physiological effects of cardiovascular agents; K. Greeff (ed.), Cardiac Glycosides, 2 vol. (1981), and Philip Needleman (ed.), Organic Nitrates (1975), collections of review articles on the basics of cardiovascular pharmacology; E.M. Vaughan Williams, Antiarrhythmic Action and the Puzzle of Perhexiline (1980), an account of different types of antidysrhythmic drugs; Peter H. Stone and Elliott M. Antman (eds.), Calcium Channel Blocking Agents in the Treatment of Cardiovascular Disorders (1983), a collection of papers on the therapeutic uses of this group of drugs; and P.A. Van Zwieten (ed.), Pharmacology of Antihypertensive Drugs (1984), a survey of hypotensive agents and their use in therapy. Drugs affecting blood Robert W. Colman et al. (eds.) Hemostasis and Thrombosis: Basic Principles and Clinical Practice (1982), a comprehensive treatment of drugs used in blood coagulation disorders; H.E. Karges and N. Heimburger (eds.), Aspects of Blood Coagulation and Fibrinolysis (1983), a collection of research articles; David Bergquist, Postoperative Thromboembolism: Frequency, Etiology, Prophylaxis (1983; originally published in Swedish, 1981), an analysis of the disorder and its therapy; and Gesina L. Longenecker (ed.), The Platelets: Physiology and Pharmacology (1985), a study of the effects of drugs on blood platelets. More advanced information on specific aspects of hemostasis and drug action is to be found in specialized journal articles such as W.H. Frishman, Antiplatelet Therapy in Coronary Heart Disease, Hospital Practice, 17(5):7386 (May 1982); G.V.R.K. Sharma et al., Thrombolytic Therapy, The New England Journal of Medicine, 306(21):126876 (May 27, 1982).Specific groups of drugs are studied in the following works: W.C. Bowman, Pharmacology of Neuromuscular Function with Special Reference to Anesthetic Practice (1980), an examination of drugs affecting neuromuscular transmission; Edith Blbring (ed.), Smooth Muscle: An Assessment of Current Knowledge (1981), a collection of articles on anatomical, physiological, biochemical, and pharmacological aspects; Susan M. Barlow and Frank M. Sullivan, Reproductive Hazards of Industrial Chemicals: An Evaluation of Animal and Human Data (1982); John A. Thomas and Edward J. Keenan, Principles of Endocrine Pharmacology (1986), an analysis of the effects of drugs on reproductive organs; and Donald W. Seldin and Gerhard Giebisch (eds.), The Kidney: Physiology and Pathophysiology (1985), a study of drugs used in treating kidney diseases. For information on topically applied drugs, the above mentioned general sources are useful, as are Frederick H. Meyers, Ernest Jawetz, and Alan Goldfien, Review of Medical Pharmacology, 7th ed. (1980); and Kenneth L. Melmon and Howard F. Morrelli (eds.), Clinical Pharmacology: Basic Principles in Therapeutics, 2nd ed. (1978). The comprehensive texts cited above also cover hormones and other body chemicals used as drugs; see also Mauricio Rocha E Silva (ed.), Histamine II and Anti-Histaminics: Chemistry, Metabolism, and Physiological and Pharmacological Actions (1978); and C.R. Ganellin and M.E. Parsons (eds.), Pharmacology of Histamine Receptors (1982). For discussion of the many aspects of antimicrobial therapy and chemotherapy, see Drug Facts and Comparisons (annual, with monthly loose-leaf updates), which describes mechanisms of action, pharmacological properties, and recommended uses; Mark Abaramowicz (ed.), Handbook of Antimicrobial Therapy, rev. ed. (1980), a reference source that gives a summary of antimicrobial agents, their use for specific diseases, doses, costs, and adverse effects; Victor Lorian (ed.), Antibiotics in Laboratory Medicine, 2nd ed. (1986), a description of the methods used for the measurement of antimicrobial agents and their effects; K.G. Nicholson, Antiviral Therapy: Respiratory Infections, Genital Herpes, and Herpetic Keratitis, The Lancet, 2(8403):617621 (Sept. 15, 1984); Raphael Dolin, Antiviral Chemotherapy and Chemoprophylaxis, Science, 227(4692):12961303 (March 15, 1985); and Daniel P. Stites et al. (eds.), Basic & Clinical Immunology, 5th ed. (1984). Humphrey P. Rang C. Robin Ganellin Jeffrey S. Fedan Alan William Cuthbert John A. Thomas Irvin S. Snyder