Science and Profession (Magill’s Medical Guide, Sixth Edition)
The science of pharmacology includes the history, source, physical and chemical properties, and biochemical and physiological effects of therapeutic chemicals, diagnostic chemicals, toxins, and related substances.
“Drug” is a noun in common usage, but it has complex meanings, some of which are almost mystical. “Drug” or “medicine” is often used today to indicate a therapeutic substance usually obtained from a pharmacy or drugstore. “Drug” also is used to indicate an illegal substance used for mood-altering effects. Historically, people made their own drugs from materials found naturally in plants, animals, and minerals; some people continue to do so. The term “drug” in this article will focus on the meaning as it is understood by scientists called pharmacologists. Any chemical can be thought of as a drug by a pharmacologist: A drug is simply a chemical that produces a change in a biological process.
Water and oxygen can be thought of as drugs, as can foods and poisons. “Drug,” therefore, is a word to indicate an idea, concept, or perception about a chemical. When the chemical, such as oxygen, is causing a change in a biological process, then the chemical is acting as a drug. If the same chemical is causing a change in some other kind of system—for example, causing an iron rod to rust—then the chemical is not acting as a drug. Drugs may be found in nature or made using human skills....
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Diagnostic and Treatment Techniques (Magill’s Medical Guide, Sixth Edition)
Three examples of the use of therapeutic chemicals in the field of pharmacology are anesthesia, cardiac-enhancing drugs, and drugs that fight infections. These examples demonstrate the use of various classes of drugs and provide insight to the variety of drug action.
Anesthetics are chemical painkillers. They are very important drugs because most diseases are accompanied by pain. Often, the first objective of a patient is to get relief from the pain, even though the anesthetic may do nothing to cure the disease. Pain is a sensation felt in the brain, not at the site of injury. Special nerves at the site of injury send a signal (nerve impulse) to the brain, where it is interpreted as pain occurring at a specific location in the body. Mild pain and severe pain are detected by different kinds of nociceptive (pain) nerves. As pain increases in severity, the brain not only perceives and interprets the pain but also sends out special autonomic signals.
Autonomic signals from the brain serve an extremely important function: They control body functions that do not require conscious thought, such as sweating, heart rate, blood pressure, digestion, and eye focus. Autonomic signals coordinate these functions and change them in response to conditions outside the body. When the body is threatened, such as when a person is frightened, autonomic signals prepare the body to fight or to flee the threatening...
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Perspective and Prospects (Magill’s Medical Guide, Sixth Edition)
In the prehistoric world, priests were called upon to intercede for persons suffering from disease and pain. As humans gained experience and developed a means of sharing that experience, especially through written records, it was noticed that certain components of the diet could reliably inflict or relieve pain; these were the first drugs. Similar effects could be obtained by inhaling natural materials or applying them to the skin through rubbing or injection. Such activities were thought to involve supernatural powers, however, and authority to use these drugs was still relegated to members of the priesthood, namely, medicine men or shamans.
Writings about the medicinal properties of natural materials can be found in Chinese, Egyptian, Greek, Indian, and Sumerian manuscripts, some of which are thought to be six thousand years old. The Ebers Papyrus of Egypt (1550 b.c.e.) contains more than eight hundred prescriptions using seven hundred drugs. It was known that some drugs were cathartics, some were diuretics, and others were purgatives, soporifics, or poisons. Yet factual knowledge about why these actions occurred was lacking, in large measure because knowledge of body function and chemistry was lacking. In this absence, people speculated that drug action was due to “essential properties” of the drug, such as warmth or wetness.
Only with the European Renaissance in the early sixteenth century was the...
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For Further Information: (Magill’s Medical Guide, Sixth Edition)
American Pharmaceutical Association. Handbook of Nonprescription Drugs. 15th ed. Washington, D.C.: Author, 2006. This drug reference work contains excellent background sections on the diseases treated by the thousands of drugs listed. It also is well illustrated.
Brunton, Laurence L., et al., eds. Goodman and Gilman’s The Pharmacological Basis of Therapeutics. 11th ed. New York: McGraw-Hill, 2006. The premier authoritative reference on the pharmacology of therapeutic drugs in humans. It is written for scientists and medical specialists, but the diligent layperson can learn much from it.
Griffith, H. Winter. Complete Guide to Prescription and Nonprescription Drugs. Revised and updated by Stephen Moore. New York: Penguin Group, 2010. Compiled by a highly experienced physician, this paperback book provides the layperson with useful and authoritative descriptions of more than seven hundred generic drugs. These drugs are cross-indexed by drug classes and brand names.
Liska, Ken. Drugs and the Human Body, with Implications for Society. 8th ed. Upper Saddle River, N.J.: Pearson/Prentice Hall, 2009. Examines the use of drugs in the North American culture by discussing such topics as what constitutes a drug and where drugs come from, drug metabolism, the different classifications of drugs, and federal laws that can be applied generally to many drug categories, including...
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Pharmacology (Encyclopedia of Nursing & Allied Health)
Pharmacology is the study of how drugs act on biological systems.
Pharmacology is the science of understanding how drugs act on the body and conversely, how the body acts on drugs. This is not to be confused with pharmacy, which deals with the preparation and dispensing of drugs. Drugs can be defined as chemical compounds with a specific therapeutic function, such as aspirin. Pharmacology focuses on how a drug gets into the body, where in the body the drug acts, and how the body gets rid of a drug. In addition, a pharmacologist will also study the therapeutic potential of a drug, the interaction of a drug with other drugs, and analyze adverse drug reactions, otherwise known as toxicities. There are several subdivisions and sub-disciplines of pharmacology which use the basic principles of pharmacology in different ways.
Pharmacology can be divided into subdivisions based on the body organ being studied. These include, but are not limited to, neuropharmacology, cardiovascular pharmacology, endocrine pharmacology, and chemotherapy. Neuropharmacology deals with the effect of drugs on the nervous system, which includes the brain, spinal cord, and nerves. Neuropharmacology includes the study of drugs of abuse such as heroin and also drugs used to treat nervous system disorders such as L-dopa, which is given to Parkinson's disease patients. Cardiovascular pharmacology focuses on drugs that modify the heart and vascular system. Blood pressure medications would be studied under this category. Endocrine pharmacology focuses on the interaction of drugs with various hormones or hormonal systems. Birth control pills would fall under the division of endocrine pharmacology. Lastly, the division of chemotherapy studies the pharmacology of drugs used to treat cancer such as tamoxifen used in breast cancer.
In addition to dividing the field of pharmacology on the basis of the targeted organ system, pharmacology can also be divided into sub-disciplines. These sub-disciplines include, but are not limited to, molecular pharmacology, behavioral pharmacology, and clinical pharmacology. Molecular pharmacology studies the interaction of drugs at the cellular level. This includes studies on the interaction of drugs with protein receptors expressed on the surface of the cell. For example, the asthma drug, albuterol, interacts with beta receptors in the lung to increase airflow. The effect of drugs on behavior is the
basis for the behavioral pharmacology discipline. Behavioral pharmacology includes addiction research which tries to understand why people become addicted to drugs like alcohol. The field of clinical pharmacology focuses more on the therapeutic use of drugs, the interactions of drugs with one another in the body, and the nature of adverse drug reactions.
The various subdivisions and disciplines of pharmacology pursue the discovery and understanding of drugs for the purpose of treating a disease or condition, such as high blood pressure. The basic principles of pharmacokinetics, pharmacodynamics, and efficacy are universal across the various areas of pharmacology. A significant amount of pharmacology research is spent on identifying new drugs to treat disease. In addition, it is important to predict drug toxicities or adverse reactions. This is accomplished by studying the pharmacokinetics of a drug. Pharmacokinetics is basically how drugs get into the body and how they get out. It describes the relationships between drug dosage and drug blood levels, which can be influenced by individual differences in drug absorption, distribution, metabolism, and elimination. This is important because if a drug is eliminated by the kidneys and a patient has damaged kidneys, then the drug could accumulate in the patient to fatal levels. Pharmacokinetic calculations can be used to determine the dose needed to give safe and effective blood levels in this situation. A significant amount of pharmacology research is also spent on understanding how drugs act on the body. This is important to understanding adverse reactions, drug interactions, and also for the design of better drugs. This area is known more specifically as pharmacodynamics. Pharmacodynamics is basically how drugs interact with the body. Many drugs bind to protein receptors on the surface of a cell. Pharmacodynamics strives to understand how tightly a drug binds to its receptor and what happens inside the cell upon drug binding. Lastly, the overall outcome of drugs on the human condition is studied and this is known as efficacy. Efficacy deals with analyzing how well a drug may correct a condition such as arthritis. All three principles, pharmacodynamics, pharmacokinetics, and efficacy, play a pivotal role in pharmacology research.
Many pharmacologists work in a laboratory research setting conducting experiments with various drugs. These experiments may be done in animal models of disease or at the biochemical level. Pharmacologists are employed by universities, commercial companies such as a pharmaceutical company, or by the government. University settings are often associated with medical centers and pharmacology research projects are largely funded by grants from outside resources. Many pharmacologists in academic settings study very focused areas in which they are interested. Academic labs are headed by a Ph.D. scientist who will lead a team of technicians and students. Academic pharmacology projects tend to focus on how different drugs work and why. Pharmaceutical settings usually have a basic pharmacology research division, a clinical trials division, a production area, and a quality assurance team. A pharmaceutical company may hire a pharmacologist to discover new drugs or to study existing ones for adverse reactions. Pharmaceutical companies conduct very detailed clinical trials in order to have drugs approved by the FDA (U.S. Department of Health and Human Services Food and Drug Administration). Pharmaceutical companies spend a significant amount of money and employ many scientists in order to prove that a drug is safe and useful in treating a particular disease or condition. A pharmacologist may also be hired by a government agency such as the FDA to conduct research on drugs or to review drug approval applications. The FDA is also responsible for monitoring the safety of already approved drugs and therefore hires pharmacologists to monitor approved drugs as well as establish guidelines. All three settings, academic, commercial, and government, provide viable and exciting opportunities for a pharmacologist.
A typical workday for a pharmacologist depends on the sub-discipline the pharmacologist works in. A molecular pharmacologist may spend a significant portion of the day at the lab bench conducting experiments in test tubes. A behavioral pharmacologist may spend the day observing animals treated with certain drugs. A clinical pharmacologist is more likely to spend time evaluating data from patients taking certain medications. These workdays are typical of traditional research pharmacologists. Pharmacologists in more non-traditional careers may be involved in the business or legal side of science. In other words, pharmacologists are not limited to just experimental research in a laboratory setting.
Education and training
In order to become a pharmacologist, a college degree is required. High school students should take biology, chemistry, and math classes. Several undergraduate institutions now offer a bachelor of science degree in pharmacology. College level courses in biology, biochemistry, anatomy, and physiology are required. The field of pharmacology also requires the use of statistics and laboratory mathematics, and students should complete a statistics course. Undergraduate pharmacology majors should also take chemistry courses, including basic chemistry and organic chemistry. The undergraduate science courses should have a practical laboratory component to prepare students for careers in a laboratory research setting. Students should also pursue undergraduate research projects and look for internship opportunities at pharmaceutical or biotechnology companies. Research associate positions in industry are available for pharmacology college majors, but experience in a laboratory research setting is a must for many of these job opportunities. Universities also hire lab technicians with a college level pharmacology background.
Advanced education and training
Most pharmacologists have advanced degrees at the masters or Ph.D. level. Many universities offer graduate degree programs in pharmacology. Students pursuing a graduate degree should have a baccalaureate degree in biology, chemistry, or related field. Ph.D. students take in depth courses in physiology and pharmacology. In addition, a major requirement for a Ph.D. is a dissertation research project that is conducted over several years. The Ph.D. student is required to publish novel findings in peer-reviewed scientific journals. After completing a Ph.D. in pharmacology, many graduates go on to postdoctoral research training. Postdoctoral training may be in an academic or commercial setting. This training period has an indefinite time length. Many pharmacologists will then go on to become professors at universities or enter the commercial workforce as research scientists.
The field of pharmacology is experiencing rapid growth and prospects for pharmacologists continue to look good. The mapping of the human genome will provide new insights into designing better drugs and will create a need for more pharmacologists to make use of this new information. Many pharmaceutical companies are hiring pharmacologists for their drug discovery research projects. The pharmaceutical industry is a $300 billion dollar a year industry and this rapid growth is expected to continue.
Efficacyhe effectiveness of a drug in treating a disease or condition.
Pharmacodynamicshe way a drug acts on tissues and cells in the body.
Pharmacokineticshe route and rate at which a drug gets in and out of the body.
The Insider Guide to Jobs in the Biotech and Pharmaceuticals Industry. Version 5.0. San Francisco: Wet Feet Press, 1999.
Kling, James. "Industry Seeks Classically Trained: Calling All Pharmacologists." The Scientist 13 (1999).
Wilson, Jennifer. "Working in Drug Discovery Research: Academia is Not the Only Route for Ph.D.s." The Scientist 15 (2001).
American Society for Pharmacology and Experimental Therapeutics. 9650 Rockville Pike, Bethesda, MD 20814.(301) 530-7060. <<a href="http://www.faseb.org/aspet/">http://www.faseb.org/aspet/>.
Susan M. Mockus, Ph.D.
Pharmacology (Encyclopedia of Drugs, Alcohol, and Addictive Behavior)
In its broadest sense, pharmacology can be defined as the science dealing with interactions between living systems and moleculesn particular, chemicals (i.e., drugs)sually introduced from outside the system. This definition also includes medical pharmacology, which is the science of drugs used to prevent, diagnose, and treat disease. Also included are the important roles played by chemicals in the environment that can cause disease, as well as the use of certain chemicals as molecular probes for the study of normal biochemistry and physiology. Toxicology is the branch of pharmacology that deals with the undesirable (i.e., toxic) effects of chemicals in biological systems.
(SEE ALSO: Drug; Drug Metabolism; Drug Types; Pharmacodynamics; ; Poison)
BENET, L. Z., MITCHELL, J. R., & SHEINER, L. B. (1990). General principles. In A. G. Gilman et al. (Eds.), Goodman and Gilman's the pharmacological basis of therapeutics, 8th ed. New York: Pergamon.
NICK E. GOEDERS