What is Metabolism?
Detoxification of breakdown of substance into metabolites that can no longer exert and effect and that can be eliminated from the body.
What are the Routes of Administration?
Oral, Injection (IV, IM, SQ), Inhalation, Mucous membranes, skin
What is Passive Diffusion?
the movement of a substance, usually across a plasma membrane (blood vessel) by a mechanism that does not require metabolic energy
What is Active transport?
The transport of ions, nutrients or other molecules into a cell against a concentration gradient and requires the expenditure of energy.
What is First pass metabolism
the breaking down of substances by drug-metabolizing enzymes (GI Tract or Liver) prior to reaching the brain
What is the circulation route for Oral, mucous, skin, IM or SQ?
absorbes into blood stream to right-side of heart, to lungs, to left side of heart, to brain
What is the circulation route for IV injected drugs?
requires no absorption; goes to to right-side of heart, to lungs, to left side of heart, to brain
What is the Absorption time for skin (patch)?
hours to days depending on substance and delivery mechanism
Variants in times for onest of action result in _______ rate not ______ rate.
absorption; distribution rate
What is Concentration gradient force?
helps maintain an equilibrium or balance by the rate-of-change in volume or mass of substance in an area at any given time.
What kind of molecules can pass through capillaries?
small lipid-soluble and larger lipid-insoluble (water-soluble); not red blood cells or protein cells
What does Protein bound mean?
substances attached to protein cells in the blood and, therefore, unable to leave the bloodstream
What are the Body membranes that affect drug distribution?
Cell membranes; capillaries; blood-brain barrier; placental barrier
What can pass to the blood brain barrier?
Small lipid-soluble can pass, but not larger water soluble molecules
What can pass to the placental barrier?
lipid-soluble can pass readily and without limitation primarily by passive diffusion
What is the major route of drug elimination from the body?
Major route of elimination is renal (kidney) excretion of drug metabolites produced by hepatic (liver) metabolism of the parent drug
What are the Roles of kidney in drug elimination (2)?
Excretion of products of body metabolism; maintenance of body fluid levels
What are theRoles of liver in drug elimination (2)?
Converting psychoactive parent drugs to inactive metabolites (deactivate); converting highly lipid-soluble molecules to water-soluble metabolites
What factors can affect drug biotransformation by increasing or decreasing the rate of drug elimination
Genetic, environmental and physiological factors
What drug is an exception to to drug elimination?
Ethyl Alcohol - constant amount of alcohol is metabolized per hour
What is the definition of drug tolerance?
A state of progressively decreasing responsiveness to a drug; a person requires a larger dose of a drug to achieve the originally obtained effect by a smaller dose.
What is Metabolic tolerance?
The increased capacity of the liver to metabolize the parent drug molecule through increased enzyme levels.
What is Cellular-adaptive or pharmacodynamic tolerance?
The adaptation of the brain cells to the continued presence of the drug by down regulation.
What is down regulation?
The reduction of the number of receptors available to the drug and reduction of the sensitivity to the drug.
What is behavioral conditioning?
Comes from routinely pairing environmental cues with drug administration so that the conditioned stimuli will elicit a conditioned response that is opposite in direction or compensation for the direct effects of the drug.
What is physical dependence?
Means a person needs to continue the use of a drug to avoid withdrawal symptoms (occurrence of physical and/or psychological changes.)
What is psychological dependence?
Means a person craves the drug long after the withdrawal symptoms have subsided.
What is positive reinforcement?
Refers to the likelihood of repeating a given behavior that elicits or produces a desired effect.