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Pharmacology Essays Free

Essay about Pharmacology

620 WordsOct 25th, 20123 Pages

Essay
Pharmacology is the branch of medicine and biology that seeks to understand drugs and how they affect the body. It involves the analysis of how drugs interact with the biological function of the body and how these drugs react with each other, their natures, and their properties. All drugs are considered chemicals and when ingested into the body an affect from the drug takes place. According to Doweiko (1999), “A drug is essentially a foreign chemical that is introduced into the individual’s body to bring about a specific desired response. There are many forms of drugs and how these drugs are administered in the body determines the kind of result that will take place. The Central Nervous System, (CNS) plays a major role in how these…show more content…

Biotransformation involves the way in which the organism copes with potentially dangerous compounds found. They detoxification systems will try to eliminate poisonous food substances as well as drug molecules because they act as toxic agents to the body (Doweiko, 2009). Biotransformation is generally carried out in the liver although some tissues might also be involved in this process as well (Doweiko, 2009). The way the human digestive tract works is that it is designed not to allow any chemical to that has been absorbed to pass into circulation until it is first filtered through the liver (Doweiko, 2009). The liver acts as a kind of water purifier when it comes to the body. The bad substances are filtered out so that the body can keep most of the good substances.
In order to decipher how effective a drug will be, the duration of the drug effect, and how long the drug will remain in the body is usually determined by what is called a drug half-life. This is especially important when dealing with and understanding overdoses. As counselors, it isn’t necessarily our responsibility to fully understand the biology behind drugs and alcohol’s affects on the human body. However, it is valuable and important for counselors to have a basic understanding and be fairly knowledgeable in how drugs and alcohol affect the body so that they can

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? HISTORY OF PHARMACOLOGY Pharmacology Is the scientific study of the origin, nature, chemistry, effects, and uses of drugs Pharmacology is not synonymous with pharmacy. Pharmacology deals with how drugs interact within biological systems to affect function, while pharmacy is a medical science concerned with the safe and effective use of medicines. Brief History of Pharmacology Primitive Period Primitive people uses drugs for mystical or magic powers rather than their physiologic effect They believed that evil spirits caused diseases.

Alcohol and opium were one of the first medicinal plants Ancient Period Egypt — cradle of civilization – oldest phase of medicine Ebers Papyrus — written 3,000 years ago, an Egyptian medical source that listed 700 different remedies to treat specific ailments. It covers different prayers in driving away diseases and specific recipes for drugs (e. g. aloe, oil, opium, peppermint, and vinegar) Greece — pharmaceutical history begins with legends of gods and goddesses Aesculapius – god of healing Hippocrates – father of medicine.

Dioscorides – Greek physician who wrote the Materia Medica, which specifically described 600 different plants and classified them by substance rather than by the disease they intend to treat.

This became the main source of pharmaceutical knowledge up to the 16th century Rome – after the Roman conquest of Greece, Greek medicine migrates to Rome Galen – a Greek physician who established a system of medicine and pharmacy – He was the first to prepare the cold cream and rose water ointment Medieval Period Dark Age – a period of about 600 years, characterized by the destruction of old civilization and little progress in learning.

There was a spread in Christianity and the establishment of the Venerable Bede- a medieval monastery where monks preserved their works on pharmacy and medicine on manuscripts Arabian Influence – establishment of schools and hospitals and discovery of many new drugs. Arabs are the originator of syrups, alcohol, and aromatic water. They produced the first pharmaceutical formula or set of standards (Apothecary System) Geber – the first great Mohammedan and reputed discoverer of nitric acid, sulfuric acid, and nitro hydrochloric acid – “Father of Arab Chemistry”.

16th Century Paracelsus – “Father of Pharmacology” Swiss scientist that first advocated the use of a single drug rather than mixtures and potions (advantage: the dosage of a single dose can be regulated more precisely than that of complex mixtures Improved pharmacy and therapeutics, introducing new remedies and compounds and reducing overdosing 17th Century Great interest was displayed in chemistry and pharmacy and many preparations are in use. Ex. Cinchona bark – discovered by the Indians; used in treating and preventing malaria.

Syrup of ipecac – discovered by the natives of Brazil; used for amoebic dysentery William Harvey – explained how drugs exert beneficial or harmful effects. He also demonstrated the circulation of blood in the body and introduced a new way of administering drug – Intravenously 18th Century Edward Jenner – an English physician who made the first public inoculation of smallpox vaccine in 1756 William Withering – an Englishman who introduced the infusion digitalis for the treatment of heart disease.

19th Century Friedrich Serturner – a German pharmacist who discovered alkaloid morphine substance. Francois Magendie & Claude Bernard – with the use of purified drug, they demonstrated that certain drugs work at specific sites of action within the body. The French Codex was the first important pharmacology book to be produced in 1818. Ether and Chloroform were first used as general anesthesia in the 1840s. 20th Century Important legislation was instituted to control the manufacture and sales of drugs.

These include the Food and Drug Act of 1906 & 1938 and the Harrison Narcotic Drug Act of 1914 & Controlled Substance Act of 1970. Lister & Semmelweis – introduced the use of antiseptics to prevent infection during surgery Two early landmarks in the 20th century: Ehrlich – introduced Salvarsan for treating syphilis and responsible for the introduction of antibiotics Banting & Best’s discover of insulin in treating diabetes. Definition of Term Drugs – a. k. a. medications.

Any chemical substance which affects living system Chemical and medicinal compounds used for treatment of disease, for the prevention of illness of pathologic states and for diagnosing disease condition. Pharmacology – science concerned with the history, sources, physical and chemical properties of drugs as well as the ways in which drug affects the living system A branch of knowledge that has to do with the chemicals that have biological effect. Subdivisions/ Branches of Pharmacology.

Pharmacognosy – the branch of pharmacology dealing with the economic, biological and chemical aspects of natural drugs and their constituents. The study of the sources of drugs and the physical characteristics of crude or unrefined drugs. Study of drugs derived from herbal and other natural sources and how the body reacts to them. Pharmacokinetic – deals with the absorption, distribution, biotransformation, and excretion of drugs and/or its chemical byproducts in various body sites as well as the time required for these drug concentration to develop and/or change.

Absorption – movement of drug particles from the GI tract to body fluids by passive absorption, active absorption Distribution – is the process by which the drug becomes available to body fluids and body tissue or the drug is carried from its site of absorption to its site of action Metabolism/Biotransformation – when drugs are inactivated by liver enzymes and are then converted or transformed by hepatic enzymes to inactive metabolites or water-soluble substance for excretion.

Process of energy and transformation in all living cells. Excretion – elimination of drugs or its chemical byproducts in various body sites (i. e. bile, feces, lungs, saliva, sweat, and breast milk). The site, by which the drug is excreted. Pharmacodynamics – study of the biochemical and physiological effects of drugs as well as their mechanism of action. Pharmacologist – is a scientist who specializes in the study of pharmacodynamics, employing all kinds of biochemical, physiological, and other techniques.

Pharmacotherapeutics – study of how drug may be used in the treatment of disease, that is, which among the drugs would be most effective or appropriate for a specific disorder or what dose would be required. Pharmacy – the study of techniques involved in the preparation, compounding, dispensing, preservation and storage of the drugs for medical use. Pharmacist – one who is qualified and licensed to prepare and dispense drugs; responsible for the manufacture of the dosage form of drugs (e. g. tablets, capsules, etc.)

Pharmacogenetics – the study of genetically-determined reactions of drugs in the human body. Toxicology – study of poisonous effects of drugs Drug therapy – the proper administration of drugs used to treat disease Drug Standards and Legislation Drug Standards The United Pharmacopoeia National Formulary (USP NF) The current authoritative source for drug standards (revised every 5 years by a group of experts in nursing: pharmaceutics, pharmacology, chemistry, and microbiology Drugs included in the USP-NF have the standards for:

Therapeutic use Client safety Quality Purity Strength Packaging Dosage form International Pharmacopoeia – first published in 1951 by WHO Provides basis for standards in strength and composition of drugs worldwide Published in English, Spanish, and French (revised every 5 years)

FEDERAL LEGISLATION Purpose – to ensure safety (drugs that are impure, toxic, ineffective, or not tested before public sale) do not include drug effectiveness and drug safety 1938:

Food, Drug, and Cosmetic Act empowered a governing body—the Food and Drug Administration (FDA) and Cosmetic Act of 1938 Purpose: to monitor and regulate the manufacture and marketing of drugs FDA’s responsibility is to ensure that all drugs are tested for harmful effects, have labels with accurate information, drug literature that explains adverse effects 1952:

Durham-Humphrey Amendment amendment to the FDA and Cosmetic Act of 1938 distinguished between drugs that be sold with or without prescription and those that should not be refilled without a new prescription (ex. Narcotics, hypnotics, or tranquilizers; must be labeled) It also specified that all other drugs are approved for use to be considered non-prescription drugs 1962:

Kefauver-Harris Amendment tightened controls on drug safety, especially experimental drugs, and required that adverse reactions and contraindications must be labeled and included in the literature it added requirements that both prescription and non-prescription drugs be shown to be effective as well as safe Thalidomide tragedy 1950 – pregnant European women who took the sedative-hypnotic thalidomide during their first trimester of pregnancy gave birth to infants with extreme limb deformities 1970:

The Controlled Substance Act The Controlled Substance Act of the Comprehensive Drug Abuse Prevention and Control Act, title II, was passed by the congress.

Provision: The promotion of drug education and research into the prevention and treatment of drug dependency The strengthening of enforcement authority The establishment of treatment and rehabilitation facilities.

The designation of schedules, or categories of controlled substances according to abuse liability Drug Enforcement Administration (DEA) charged with the role of being the Nation’s sole legal drug enforcement agency Bureau of Narcotics and Dangerous Drugs was closed before DEA took place A German pharmaceutical company, Chemie Grunenthal at Stolberg, Synthesized Thalidomide in West Germany in 1953.

It had accidentally been discovered during a search for cheap antibiotics, But was soon marketed with little evidence as a sedative. In 1961 the drug Was found to be harmful to the unborn children of pregnant women 1978:

Drug Regulation Reform Act This reform act shortened the time in which new drugs could be developed and marketed. 1992: Drug Relations Act The regulations were changed to increase the approval rates of drugs used to treat AIDS and cancer The pharmaceuticals pay a user’s fee at the time they file the application for the new drugs (for FDA approval process).

1997: The Food and Drug Administration Modernization Act 5 Provisions included in this act: Review and use of new drugs is accelerated. Drugs can be tested in children before marketing. Clinical trial data is necessary for experimental drug for serious or life-threatening health conditions. Drug companies are required to give information on “off-label” drugs (non-FDA approved drugs) and their uses and costs Drug companies that plan to discontinue drug must inform health professionals and clients at least 6 months before stopping drug production.

Drug Pregnancy Categories CATEGORY A: No risk to fetus. Studies have not shown evidence for fetal harm. CATEGORY B: No risk in animal studies, and well-controlled studies in pregnant women are not available. It is assumed there is little to no risk in pregnant women. CATEGORY C: Animal studies indicate a risk to the fetus. Controlled studies on pregnant women are not available. Risk versus benefit of the drug must be determined. CATEGORY D: A risk to the human fetus has been proven.

Risk versus benefit of the drug must be determined. It could be used in life-threatening conditions. CATEGORY X: A risk to the human fetus has been proven. Risk outweighs the benefits and drug should be avoided during pregnancy. Drug Names Chemical Name – describes the drug’s chemical structure Generic Name – the official or non-proprietary name for the drug this name is not owned by any pharmaceutical (drug) company and is universally accepted Brand Name or Trade Name – also known as proprietary name

also chosen by the drug company and is usually a registered trademark owned by that specific manufacturer Drug Uses The most common drug use is symptomatic treatment. Many drugs are used to relieve disease symptoms. Preventive drug helps the body avoid disease Diagnostic drugs help the physician determine whether a disease is present Curative drugs eliminate the disease. Health maintenance drugs help the body to function normally. Contraceptive drugs prevent pregnancy.

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