The mechanisms of action by which drugs produce their effects (desired or undesired) based on time and dose.
How drugs move through the body in the processes of absorption, distribution, metabolism, & excretion.
Study of medicinal uses of drugs.
3 Medicinal Uses of Drugs
Prevent & diagnose disease, therapeutic use.
Drugs mixed in a formulation w/ other ingredients to improve the stability, taste, or physical form to allow appropriate administration of the drug.
Any substance or product that is used or intended to be used to modify a physiologic or pathologic condition. Drugs exert their effects by potentiating, interrupting, or replacing/blocking a normal cell process.
Name given to a drug that describes its molecular structure and distinguishes it from all other drugs.
Name given to a drug that is assigned by the US adopted names council.
Trade name of a drug.
Drugs that have the same active ingredients but may have different inert ingredients; identical in strength & dose to their brand name.
Schedule I Drug
Schedule of controlled substance that has a high potential for abuse w/ no currently accepted medical use in the US, or lack of accepted safety.
Schedule II Drug
Schedule of controlled substance that has a high potential for abuse w/ accepted medical use in the US; use may lead to severe psychological or physical dependence.
Schedule III Drug
Schedule of controlled substance that has abuse potential less than codeine or morphine type drugs; contains Vicodin & T-3.
Schedule IV Drug
Schedule of controlled substance that contains Xanax & Ambien.
Schedule V Drug
Schedule of controlled substance that has the lowest potential for abuse.
Originating within the body (eg: hormones).
Originating outside the body.
Desired therapeutic effect of a drug.
Effects other that the primary effect that result from the administration of a drug.
Undesirable effect that result from the administration of a drug.
Proteins, typically on the cell surface, which receive and process chemical signals. The molecular signals which binds to the receptor may take the form of hormones, neurotransmitters, or pharmacological agents.
The mechanism of action between the drug and cellular components.
Downregulation and Upregulation of Receptors
A cell's ability to respond to a chemical the number and sensitivity of receptors. Receptors can be increased, or upregulated, when the signal is weak, or decreased, or downregulated, when it is strong.
A drug’s ability to bind to a given receptor.
Ability of drug to produce desired pharmacological effect as measured concentration or dosage of the drug required to produce the effect.
Capacity of a drug to elicit a response.
Drugs that interact or bind with a receptor which inhibits the effect of an agonist.
Time required to reduce the amount of the drug in the body to 50%.
A curve plotting the relationship between the dose of a drug administered and its pharmacological effect.
Onset of Action
Time required for a drug's effects to come to prominence after administration.
A rapidly diminished response to successive dosages, rendering the drug less effective.
The lowest dose capable of producing a measurable or perceivable effect.
Minimum Effective Concentration (MEC):
Minimum concentration of drug in plasma required to produce the therapeutic effect.
The greatest response produced regardless of the dose administered or length of time required for the drug to reach peak efficacy.
Duration of Action
The amount of time that a measurable drug effect persists after a single dose.
Range in which desired effects are produced; a comparison of the amount of a therapeutic agent that causes the therapeutic effect to the amount that causes toxicity.
Effective Dose (ED50)
Dose required to produce a therapeutic response in half of test subjects.
Toxic Dose (TD50)
Dose where Half of test subjects exhibit adverse reactions.
Lethal Dose (LD50)
Dose where half of the subjects died.
Symptoms which occur upon the abrupt discontinuation or decrease in intake of medications or recreational drugs.
A chronic and relapsing brain disease characterized by compulsive drug seeking and use, negative consequences.
Routes of Administration
The path by which a drug is administered, typically classified by application location or exposition. Some include:
- Inhalational aerosol
- Intraarticular (into joint)
- Sublingual (under the tongue)
- Sublabial or buccal (between the cheek and gums/gingiva)
- Nasal administration
The process by which a drug is ingested orally, absorbed from digestive system, and enters the portal venous system where it must first pass through the liver before reaching the general systemic circulation. First pass metabolism results in a fraction of the active drug emerging from the liver to the rest of the circulatory system. Drugs with high first pass effect have a considerably higher oral dose than sublingual or parenteral dose.
administration of a drug that avoids first pass metabolism.
Occurs predominantly in liver and kidneys, and converts active drugs to inactive metabolites.
Exercise’s effect on Pharmacokinetics
Exercise causes changes in the body's physiology that can influence the pharmacology and/or the pharmacokinetics of a drug.
Since 1999, ExRx.net has been a resource for exercise professionals, coaches, and fitness enthusiasts; featuring comprehensive exercise libraries (over 1900 exercises), reference articles, fitness assessment calculators, and other useful tools.
ExRx.net provides free content and relies on advertisement income to maintain this site. If you are using an adblocker, we kindly ask you to support us by adding this site to your adblocker’s whitelist. Other ways to support the continued development of ExRx.net is by subscribing to ExRx.net Premium Content, providing us periodic donations, or placing an order in our Store.