Drug Poisoning and Overdose

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Overview


Drug poisoning can result from an overdose of either prescribed drugs or drugs that are bought over the counter, or it can be caused by drug abuse or drug interaction. The adverse effects vary greatly depending on the type of drug and how it is taken.

More than 9 million natural and synthetic chemicals have been identified worldwide and used for various purposes; fewer than 3000 of these chemicals cause more than 95% of accidental and deliberate poisonings. Just like other chemicals, all drugs, especially when taken in large doses or over long periods of time, can initiate a toxic condition. Certain drugs used in combination result in even more profound toxic effects that are frequently life-threatening. Some drugs are particularly dangerous when taken in high doses. These are drugs that affect the nervous system, such as antidepressiants, antipsychotics, and analgesics.

Causes


Drug overdoses can be accidental or intentional. Accidental overdoses can have various causes, such as unintentional over-prescription due to irresponsible behavior or misreading of product labels, mistakes made by medical establishments or dispensaries, and unwitting ingestion by children. Drug overdoses are sometimes caused intentionally in order to commit suicide or cause self-harm.


Drugs That Affect the Nervous System


Drugs that affect the nervous system often cause adverse reactions in high concentrations. Nervous system depressants, such as barbiturates and narcotics, taken in sufficiently large doses, can result in coma and convulsions. Excessively high doses of stimulants such as amphetamines 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. In susceptible people, 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, various pigmentations, and blood cell disorders. Overdosage of an analgesic like aspirin can result in acid-base disturbances, spontaneous bleeding, and convulsions, while paracetamol can cause serious toxic effects on liver. The antibiotic streptomycin taken over long periods can result in deafness, dizziness and kidney damage.


Societal Effects of Poisonings and Overdoses


Accidental and intentional poisonings or drug overdoses contribute significantly to progression of disease, mortality, and health care expenditure. An estimated 2 to 5 million poisonings and drug overdoses occur annually in the United States, although the true incidence is unknown due to underdiagnosis and underreporting. For 40 years, deaths caused by car crashes and firearms have topped the list of injury deaths in the USA. Poisoning edged into the No. 2 position in 2004 and it continues to be the second-leading cause of injury deaths in the USA, outstripping deaths caused by firearms for the second year in a row, according to a federal report. Recent investigations have shown that rates for fatal poisonings have increased at a dramatic pace, and unintentional drug overdose deaths that can now be considered an epidemic.
Nowadays, we are facing a lot of cases of unintentional, medical and suicidal poisonings caused by either prescribed drugs, OTC products, or drugs of abuse. Some of the victims of these poisonings are celebrities. The king of pop music, Michael Jackson, died of poisoning from the anesthetic drug Propofol, which was until that particular case used only in hospitals. His doctor Conrad Murray is currently on trial under accusations of causing the drug overdose and subsequent death. Famous actor Heath Ledger also died from the abuse of prescription medications; he accidentally poisoned himself as a result of acute intoxication by the combined effects of oxycodone, hydrocodone, diazepam, temazepam, alprazolam and doxylamine.

References
1. Olson K.R. ed. Poisoning & Drug Overdose,4th ed. New York: Lange Medical Books, 2004.
2. Infoplease article on drug poisoning, accessed on 1st of May 2011.
3. Blachford S.L. and Krapp K. eds. Drugs and Controlled Substances Information for Students, Detroit:Thomson Gale, 2003.