drug poisoning

drug 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. Reaction to a drug caused by an allergic sensitivity is not considered drug poisoning. Virtually all drugs, especially in large doses or when taken over long periods of time, can initiate a toxic condition. Certain drugs used in combination, such as alcohol 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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, result in an intensified alteration of physiological state that is frequently dangerous. Drugs that affect the nervous system often cause adverse reactions in high concentrations. Alcohol and other nervous system 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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, such as barbiturates and 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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, taken in sufficiently large doses, can result in coma and convulsions. Excessively high doses of stimulants such as 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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 result in blurred vision, spasms, heart irregularities, and respiratory failure. In addition, continued use of both stimulants and depressants can lead to addiction and tolerance for toxic doses. Overdosage of an analgesic like aspirinaspirin,
acetyl derivative of salicylic acid (see salicylate) that is used to lower fever, relieve pain, reduce inflammation, and thin the blood. Common conditions treated with aspirin include headache, muscle and joint pain, and the inflammation caused by rheumatic fever and
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 can result in acid-base disturbances, spontaneous bleeding, and convulsions. Virtually all drugs produce some side effects. For example, side reactions with barbiturates may include respiratory depression and skin rashes. Other drugs cause adverse reactions when taken over long periods of time. The antibiotic streptomycinstreptomycin
, antibiotic produced by soil bacteria of the genus Streptomyces and active against both gram-positive and gram-negative bacteria (see Gram's stain), including species resistant to other antibiotics, e.g.
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 taken over long periods can result in deafness, and continued use of aspirin and other salicylatessalicylate
, any of a group of analgesics, or painkilling drugs, that are derivatives of salicylic acid. The best known is acetylsalicylic acid, or aspirin. Now often made synthetically, they were originally derived from salicin,
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 can result in kidney damage and anemiaanemia
, condition in which the concentration of hemoglobin in the circulating blood is below normal. Such a condition is caused by a deficient number of erythrocytes (red blood cells), an abnormally low level of hemoglobin in the individual cells, or both these conditions
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. Some drugs only have toxic effects on sensitive individuals. Hallucinogenic drugshallucinogenic 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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 such as LSDLSD
or lysergic acid diethylamide
, alkaloid synthesized from lysergic acid, which is found in the fungus ergot (Claviceps purpurea). It is a hallucinogenic drug that intensifies sense perceptions and produces hallucinations, mood changes, and changes in the
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 can result in hyperexcitability, coma, and prolonged psychotic states and can cause major personality changes in some users. In susceptible persons even moderate doses of phenothiazine tranquilizers, which are used to calm psychotic patients, can cause such toxic effects as low blood pressure, uncontrollable muscle movements, and various pigmentation and blood cell disorders (see phenothiazinephenothiazine
, any one of a class of drugs used to control mental disorders. Phenothiazines, along with other antipsychotic, or neuroleptic, drugs are used for such disorders as schizophrenia, paranoia, mania, psychosis resulting from mental deficiency, some forms of senility,
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).