pharm Flashcards
routes of drug administration
-Enteral-Small intestine (oral, gastric tube, suppository)
- parenteral (injection)
IV,IM, SC, INTRA-ARTERIAL,INTRASPINAL, EPIDURAL
-transdermal or topical (skin, sublingual, ophthalmic
inhalation
ottic
osseous
WHAT ARE THE 4 STAGES OF PHARMACOKINETICS
- ) ABSORPTION
- ) DISTRIBUTION
- ) METABOLISM
- ) EXCRETION
ABSORPTION
Unless delivered directly to the site, a drug must be absorbed, and then gain access to the systemic circulation
From there it is circulated to the site of action
Often this as through the small intestine, but drugs can be absorbed via multiple paths
WHAR ARE THE FACTORS AFFECTING ABSORPTION?
SURFACE AREA
BLOOD FLOW
BARRIERS THAT NEED TO BE CROSSED ( water or lipid soluble drugs)
bioavailabity
is the amount of a given drug that reaches systemic circulation
distribution
is the movement of drugs to the site of action
Preferentially delivered to organs with highest blood flow (Liver, Kidneys and Brain)
loading dose
often use to achieve a specific plasma concentration
maintenance dose
use to keep a specific plasma concentration
metabolism
is the process of transformation of a drug into its metabolites
-PRIMARILY OCCURS IN THE LIVER
This Biotransformation is usually thought of as inactivating a drug
But it may also activate it (a prodrug), alter the effect, or create toxic metabolites
first pass effect
enteral medications enter the bloodstream and go directly through the portal vein tp the liver where is metalize– whatever drug is left is then enters the systemic circulation,
excretion
removal of the drug from the body ( mostly in the renal system)
GI System
Respiratory System (anesthetics and alcohol)
Sweat
Saliva
Alternative renal therapies
clearance
is a way of describing the removal of drug from the blood stream.
half life
Is the amount of time for the concentration of the drug to decrease by half.
pharmacodynamics
is the examination of how a drug causes effect
receptor
The site where the drug causes effect
The structure of the drug must match the configuration of the proteins in order to bind on and initiate an effect
ion gates
The drug binds to an Ion Channel or Gate
This causes the Gate to open
This allows a flow of Ions into the cell
Changing the polarity of the cell
types of receptors
Binding to a Receptor that “Talks” with other
systems inside the cell
The Drug binding to a receptor triggers a chain reaction inside the cell
Multiple different ways this can occur
affinity
a measure of the tendency of a drug to combine with a particular receptor
efficacy
is a measure of the tendency of the drug-receptor complex to cause a specific response
three diff ways that a drug can act as an antagonist
competitive antagonism
functional antagonism
chemical antogonism
ED50
measure of potency the dose at which a drug produces 50% of maximal effect
maximal effect
the greatest response possible regardless of dose
therapeutic index
is the comparison of how much drug is needed to cause effect, against the amount to cause death
additive
taking two drugs which act by the same pathway, where the effect is the sum of the two
synergism
drugs with different actions taken at same time produce effect greater than sum that each would give individually
potentiation
where one drug that cannot cause an effect on its own, causes another agent to produce effects greater than capable on its own
sympathetic
Implement “fight or flight” reaction Regulate body temperature Regulate cardiovascular system Short Pre-ganglion fiber Ach into a nicotinic receptor Long Post-ganglionic fiber NE into an alpha or beta receptor Ratio of Pre-ganglionic fibers to post is 1:20 Response to stimuli is widespread and diverse
parasympathetic limb
Parasympathetic Long Pre-ganglionic fiber Ach into a nicotinic receptor Short Post-ganglionic fiber Ach into a muscarinic receptor
