drugs


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drugs,

substances used in medicine either externally or internally for curing, alleviating, or preventing a disease or deficiency. At the turn of the century only a few medically effective substances were widely used scientifically, among them etherether,
any of a number of organic compounds whose molecules contain two hydrocarbon groups joined by single bonds to an oxygen atom. The most common of these compounds is ethyl ether, CH3CH2OCH2CH3
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, morphinemorphine,
principal derivative of opium, which is the juice in the unripe seed pods of the opium poppy, Papaver somniferum. It was first isolated from opium in 1803 by the German pharmacist F. W. A. Sertürner, who named it after Morpheus, the god of dreams.
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, digitalisdigitalis
, any of several chemically similar drugs used primarily to increase the force and rate of heart contractions, especially in damaged heart muscle. The effects of the drug were known as early as 1500 B.C.
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, diphtheria antitoxin, smallpox vaccine, ironiron,
metallic chemical element; symbol Fe [Lat. ferrum]; at. no. 26; at. wt. 55.845; m.p. about 1,535°C;; b.p. about 2,750°C;; sp. gr. 7.87 at 20°C;; valence +2, +3, +4, or +6. Iron is biologically significant.
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, quininequinine
, white crystalline alkaloid with a bitter taste. Before the development of more effective synthetic drugs such as quinacrine, chloroquine, and primaquine, quinine was the specific agent in the treatment of malaria.
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, iodineiodine
[Gr.,=violet], nonmetallic chemical element; symbol I; at. no. 53; at. wt. 126.90447; m.p. 113.5°C;; b.p. 184.35°C;; sp. gr. 4.93 at 20°C;; valence −1, +1, +3, +5, or +7.
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, alcohol, and mercurymercury
or quicksilver
[from the Roman god Mercury], metallic chemical element; symbol Hg [Lat. hydrargyrum=liquid silver]; at. no. 80; at. wt. 200.59; m.p. −38.842°C;; b.p. 356.58°C;; sp. gr. 13.55 at 20°C;; valence +1 or +2.
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. Since then, and particularly since World War II, many important new drugs have been developed, making chemotherapy an important part of medical practice. Such drugs include the antibioticsantibiotic,
any of a variety of substances, usually obtained from microorganisms, that inhibit the growth of or destroy certain other microorganisms. Types of Antibiotics
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, which act against bacteria and fungi; quinacrine and other synthetics that act against malaria and other parasitic infections; cardiovascular drugs, including beta-blockersbeta-blocker
or beta-adrenergic blocking agent
, drug that reduces the symptoms connected with hypertension, cardiac arrhythmias, angina pectoris, migraine headaches, and other disorders related to the sympathetic nervous system.
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 and ACE inhibitorsACE inhibitor
or angiotensin-converting enzyme inhibitor
, drug used to reduce elevated blood pressure (see hypertension), to treat congestive heart failure, and to alleviate strain on hearts damaged as a result of a heart attack (see infarction).
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; diureticsdiuretic
, drug used to increase urine formation and output. Diuretics are prescribed for the treatment of edema (the accumulation of excess fluids in the tissues of the body), which is often the result of underlying disease of the kidneys, liver, lungs, or heart (e.g.
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, which increase the rate of urine flow; whole blood, plasma, and blood derivatives; anticoagulantsanticoagulant
, any of several substances that inhibit blood clot formation (see blood clotting). Some anticoagulants, such as the coumarin derivatives bishydroxycoumarin (Dicumarol) and warfarin (Coumadin) inhibit synthesis of prothrombin, a clot-forming substance, and other
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 such as heparinheparin
, anticoagulant produced by cells in many animals. A polysaccharide, heparin is found in the human body and occurs in greatest concentration in the tissues surrounding the capillaries of the lungs and the liver.
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 and coumarin; various smooth-muscle relaxants such as papaverinepapaverine
, alkaloid found in opium that acts as a muscle relaxant and vasodilator. The drug relaxes the smooth muscle of the larger blood vessels and is used to increase the blood supply to the brain or to the heart, as in the treatment of angina pectoris.
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, used in heart and vascular diseases; smooth-muscle stimulants; immunologic agents, which protect against many diseases and allergenic substances; hormones such as thyroxinethyroxine
, substance secreted by the thyroid gland. The hormone thyroxine forms by combining the amino acid tyrosine with iodine. Complexed to a protein, it is stored in the follicle stems between thyroid cells.
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, insulininsulin,
hormone secreted by the β cells of the islets of Langerhans, specific groups of cells in the pancreas. Insufficiency of insulin in the body results in diabetes. Insulin was one of the first products to be manufactured using genetic engineering.
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, and estrogenestrogen
, any one of a group of hormones synthesized by the reproductive organs and adrenal glands in females and, in lesser quantities, in males. The estrogens cause the thickening of the lining of the uterus and vagina in the early phase of the ovulatory, or menstrual, cycle
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 and other sex hormones; psychotherapeutics such as antianxiety drugsantianxiety drug,
drug administered for the relief of anxiety. Although their action is not fully understood, most antianxiety medications appear to affect the action of neurotransmitters in the brain (see serotonin and norepinephrine).
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 and antidepressant drugsantidepressant,
any of a wide range of drugs used to treat psychic depression. They are given to elevate mood, counter suicidal thoughts, and increase the effectiveness of psychotherapy.
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; cortisonecortisone
, steroid hormone whose main physiological effect is on carbohydrate metabolism. It is synthesized from cholesterol in the outer layer, or cortex, of the adrenal gland under the stimulation of adrenocorticotropic hormone (ACTH).
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 and synthetic corticosteroid drugscorticosteroid drug
, any one of several synthetic or naturally occurring substances with the general chemical structure of steroids. They are used therapeutically to mimic or augment the effects of the naturally occurring corticosteroids, which are produced in the cortex of the
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 used in treating inflammatory diseases such as arthritis; vitamins and dietary minerals; antidotes for poisons; and various drugs that act as stimulantsstimulant,
any substance that causes an increase in activity in various parts of the nervous system or directly increases muscle activity. Cerebral, or psychic, stimulants act on the central nervous system and provide a temporary sense of alertness and well-being as well as
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 or depressantsdepressant,
any one of various substances that diminish functional activity, usually by depressing the nervous system. Barbiturates, sedatives, alcohol, and meprobamate are all depressants. Depressants have various modes of action and effects.
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 on all or various parts of the nervous system, including analgesicsanalgesic
, any of a diverse group of drugs used to relieve pain. Analgesic drugs include the nonsteroidal anti-inflammatory drugs (NSAIDs) such as the salicylates, acetaminophen, narcotic drugs such as morphine, and synthetic drugs with morphinelike action such as meperidine
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, narcoticsnarcotic,
any of a number of substances that have a depressant effect on the nervous system. The chief narcotic drugs are opium, its constituents morphine and codeine, and the morphine derivative heroin.

See also drug addiction and drug abuse.
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, amphetaminesamphetamine
, any one of a group of drugs that are powerful central nervous system stimulants. Amphetamines have stimulating effects opposite to the effects of depressants such as alcohol, narcotics, and barbiturates.
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, and barbituratesbarbiturate
, any one of a group of drugs that act as depressants on the central nervous system. High doses depress both nerve and muscle activity and inhibit oxygen consumption in the tissues. In low doses barbiturates act as sedatives, i.e.
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 (see also anesthesiaanesthesia
[Gr.,=insensibility], loss of sensation, especially that of pain, induced by drugs, especially as a means of facilitating safe surgical procedures. Early modern medical anesthesia dates to experiments with nitrous oxide (laughing gas) by Sir Humphry Davy of England
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; psychopharmacologypsychopharmacology
, in its broadest sense, the study of all pharmacological agents that affect mental and emotional functions. The term is usually applied more specifically to the study and synthesis of drugs used in the control of psychiatric illnesses, namely the
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; hallucinogenic drughallucinogenic drug
, any of a group of substances that alter consciousness; also called psychotomimetic (i.e., mimicking psychosis), mind-expanding, or psychedelic drug.
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).

See also drug resistancedrug resistance,
condition in which infecting bacteria can resist the destructive effects of drugs such as antibiotics and sulfa drugs. Drug resistance has become a serious public health problem, since many disease-causing bacteria are no longer susceptible to previously
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; drug poisoningdrug poisoning,
toxic effects caused by an administered drug. Worldwide more than 9 million natural and synthetic chemicals have been identified; fewer than 3000 cause more than 95% of acidental and deliberate poisonings.
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; drug addiction and drug abusedrug addiction and drug abuse,
chronic or habitual use of any chemical substance to alter states of body or mind for other than medically warranted purposes. Traditional definitions of addiction, with their criteria of physical dependence and withdrawal (and often an underlying
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.

Sources of Drugs

Drugs are obtained from many sources. Many inorganic materials, such as metals, are chemotherapeutic; hormones, alkaloids, vaccines, and antibiotics come from living organisms; and other drugs are synthetic or semisynthetic. Synthetics are often more effective and less toxic than the naturally obtained substances and are easier to prepare in standardized units. The techniques of genetic engineeringgenetic engineering,
the use of various methods to manipulate the DNA (genetic material) of cells to change hereditary traits or produce biological products. The techniques include the use of hybridomas (hybrids of rapidly multiplying cancer cells and of cells that make a
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 are being applied to the production of drugs, and genetically engineered livestock that incorporate human genes are being developed for the production of scarce human enzymes and other proteins (see pharmingpharming
, the use of genetically altered livestock, such as cows, goats, pigs, and chickens, to produce medically useful products. In pharming, researchers first create hybrid genes using animal DNA and the human or other gene that makes a desired substance, such as a hormone.
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).

Pharmacopoeia and Drug Safeguards

Standards for drugs and tests for their identity, quality, and purity are given in the U.S. pharmacopoeiapharmacopoeia
or pharmocopeia
, authoritative publication designating the properties, action, use, dosage, and standards of strength and purity of drugs. It is compiled under the supervision of professional, usually governmental, authority, and all manufacture and
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, first published in 1820 and at first revised every 10 years, later every 5 years. The British publish a similar pharmacopoeia. The National Formulary published by the American Pharmaceutical Association gives the composition, description, method of preparation, and dosage for drugs; the Physician's Desk Reference is a privately published compilation of information supplied by drug companies about their drug products, published yearly. The scientific study of drugs, their actions and effects, is pharmacologypharmacology,
study of the changes produced in living animals by chemical substances, especially the actions of drugs, substances used to treat disease. Systematic investigation of the effects of drugs based on animal experimentation and the use of isolated and purified active
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.

Legislation to safeguard drug purchasers began in the United States with the Pure Food and Drugs Act of 1906; this was superseded by the more inclusive and more stringent federal Food, Drug, and Cosmetic Act of 1938. Such laws are enforced by the Food and Drug Administration. The 1962 Kefauver-Harris amendments to the Food, Drug, and Cosmetic Act increased the authority of the Food and Drug Administration to regulate testing and marketing of new drugs. There are two marketing classes of drugs: ethical drugs, for which prescriptions are needed, and proprietary drugs, which are sold over the counter without prescription. Many of the latter, such as mouthwashes, gargles, and cold preparations, are only slightly, if at all, effective in curing ailments.

Bibliography

See B. Barber, Drugs and Society (1967); C. B. Clayman, ed., American Medical Association Guide to Prescription and Over-the-Counter Drugs (1988); A. Burger, Drugs and People: Medications, Their History and Origins, and the Way They Act (rev. 1988); United States Pharmacopeial Staff, The Complete Drug Reference (1995); W. Rosen, Miracle Cure: The Creation of Antibiotics and the Birth of Modern Medicine (2017).

References in classic literature ?
A medical man should be responsible for the quality of the drugs consumed by his patients.
There's no reform in the matter: the question is, whether the profit on the drugs is paid to the medical man by the druggist or by the patient, and whether there shall be extra pay under the name of attendance.
But what I contend against is the way medical men are fouling their own nest, and setting up a cry about the country as if a general practitioner who dispenses drugs couldn't be a gentleman.
Mawmsey, who had no idea of employing Lydgate, were made uneasy by his supposed declaration against drugs, it was inevitable that those who called him in should watch a little anxiously to see whether he did "use all the means he might use" in the case.
But report took up this amazing case of tumor, not clearly distinguished from cancer, and considered the more awful for being of the wandering sort; till much prejudice against Lydgate's method as to drugs was overcome by the proof of his marvellous skill in the speedy restoration of Nancy Nash after she had been rolling and rolling in agonies from the presence of a tumor both hard and obstinate, but nevertheless compelled to yield.
And he went without shrinking through his abstinence from drugs, much sustained by application of the thermometer which implied the importance of his temperature, by the sense that he furnished objects for the microscope, and by learning many new words which seemed suited to the dignity of his secretions.
She could not bear to be in the company of the drug clerk, and when, in the evening, he came to walk with her she sent him away.
That is the same drug that I was always bringing him," said Poole; and even as he spoke, the kettle with a startling noise boiled over.
I believe," continued Lawrence, "that there have been cases where the cumulative effect of a drug, administered for some time, has ended by causing death.
He rushed downstairs and sent somebody--they said the furnace man or somebody in the basement--out to a drug store for some oil and things to bind it up with.
If Americans were reminded of the truth that price controls over pharmaceutical drugs will lead to less medical innovation and fewer choices, the poll would likely be skewed rather differently.
For specialty drugs covered under the pharmacy benefit, the trend is toward greater use of specialty pharmacies as they provide coordinated delivery of specialty drugs and management of multiple aspects of a patient's treatment.