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Toxicology is the science that investigates the adverse effects of chemicals on health.
The following is a side-by-side comparison of pharmacology and toxicology terms and concepts.
| | | Pharmacology is the scientific study of the origin, nature chemistry, effects, and use of drugs. | Toxicology is the science that investigates the adverse effects of chemicals on health. |
Dose refers to the amount of a drug absorbed from an administration. | Dose refers to the amount of a chemical absorbed into the body from a chemical. | | A drug can be administered one time, short- term, or long-term. | Exposure is the actual contact that a person has with a chemical. Exposure can be one- time, short-term or long-term. | | A dose-response curve graphically represents the relationship between the dose of a drug and the response elicited. | A dose-response curve describes the relationship of the body's response to different amounts of an agent such as a drug or toxin.
| | Routes of administration: oral, IM, IV, dermal, topical, etc. | Routes of entry: ingestion, inhalation, dermal absorption. | | With drugs there are therapeutic responses (desirable) and side effects (undesirable). Beyond the therapeutic dose, a drug may become "toxic". | In toxicology, only the toxic effects are of concern. Toxicity is the ability of a chemical to damage an organ system, to disrupt a biochemical process, or to disturb an enzyme system. | | Potency refers to the relative amount of drug required to produce the desired response. | The potency of a toxic chemical refers to the relative amount it takes to elicit a toxic effect compared with other chemicals. | | Biological monitoring is done for some drugs: Clotting time is monitored in patients on anti- coagulants like coumadin. Actual drug levels are measures for some drugs like digoxin. | Biological monitoring is done for some toxic exposures such as blood lead levels or metabolites of chemicals such as cotines for environmental tobacco smoke exposures.
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Additional Toxicology/Pharmacology comparisons:
A. The effects of drugs and hazardous chemicals can be immediate (acute), long-term or can present after a latency period often associated with cancer outcomes.
B. Host Factors must be considered when looking at therapeutic drugs or hazardous chemicals. Such factors as age, sex, genetics, weight, drugs that the person may be taking, pregnancy status, and others may effect the therapeutic or toxic effect of a drug or chemical.
C. Drugs are taken voluntarily and often under the supervision of a licensed health care provider. Hazardous chemical exposures are often involuntary.
D. The regulatory process by which a drug comes to the market includes several stages of testing with animal and human testing. The regulatory process for hazardous chemicals that are not food, drug, cosmetic, or pesticide in nature does not require ANY original testing.
E. The resources for information regarding drugs would include thePhysicians Drug Reference (PDR), the Poison Control Center, PubMed, and Medline Plus. For hazardous chemicals the Poison Control Centers can be a good source of information. The National Library of Medicine has a substantial holding of information that is currently accessible via the Web.
F. Children require special attention when administering drugs and in terms of protection from hazardous chemicals. Regarding hazardous chemicals: children are closer to the ground and more likely to be exposed to chemicals that settle on the floor and carpets (their hand-to-mouth behavior puts them at increased risk of exposure); they spend 86% of their time indoors and therefore come into contact with a large number of household chemicals and pollutants: they have greater average food intake (per body weight) than adults; they eat a smaller range of foods and express strong dietary preferences; and they breathe more air per body weight than adults. In addition, their biological systems are immature and under development. The vast majority of regulations regarding hazardous chemicals (including those in our food and water) are based on their toxicity to a middle-aged, white male. Our standards may not be protective enough for our children.
The National Library of Medicine provides a self-paced toxicology tutorial on their Toxicology and Environmental Health website.
NLM Toxicology Tutorial: Click links below to go directly to each section of the tutorial
• Toxicology Tutorial I - Basic Principals
• Toxicology Tutorial II - Toxicokinetics
• Toxicology Tutorial III - Cellular Toxicology
Last Updated: 09/18/2007 at 10:22:49 AM |
