Pharmacokinetics Flashcards
Define pharmacokinetics
how medication proceeds through the body
What are the four processes of pharmacokinetics
absorption, distribution, metabolism/biotransformation, elimination/excretion
Define pharmacodynamics
what the body does with the drug
Oral medications must be lipid soluble to enter the brain T/F
true
How fast do oral drugs take to start working
75% in 2-3 hours
Do genetics effect the oral rate of drug absorption
yes
When would you use a drug rectally
when someone is unconscious or cannot swallow
Name a disadvantage of administering a drug rectally
absorption is erratic
Sublingual or sniffing enters the body through what
mucus membranes
Absorption is slow via the mucus membrane T/F
false, it’s rapid
Nicotine patches are a form of absorption through the mucus membranes T/F
true
Name 3 injection types
intravenous, subcutaneous, intramuscular
Name the advantages of injections over other routes
fast, accurate dose, can dilute, and can use very high doses
Name disadvantages of injections
sterile technique, severe allergic reactions, medication must be fully dissolved
Psychotropic drugs are most commonly given via which type of injection
intramuscularly
Most psychotropic drugs circulate outside of the brain T/F
true, because they bind to proteins in the blood which makes less of the drug available to enter into the brain
Define solubility
dissolvability
Define binding
the degree to which molecules bind to protein molecules in the bloodstream
If medications bind to proteins will they be able to cross the blood brain barrier
no because proteins in the blood are too large to leave the bloodstream
Define metabolism
how medication is broken down by enzymes in the body
describe how most medications leave the body
the liver metabolizes the drug, which is the converted and excreted by the kidneys through urine which is where the majority of medications leave the body
grapefruit juice can inhibit enzymes and cause serious effects because of its effect on metabolism T/F
true
The intestine does not allow large molecules that are not absorbed in fat to pass through the cell membrane T/F
true, this creates a barrier to absorption and distribution
define capillaries
tiny blood vessels that connect to the smallest veins
are capillaries large enough to let fat soluble drugs in
yes, but not those bound to plasma proteins
define the blood brain barrier
the cells in the brain that protect the environment that is needed for the brain to function in a normal way and are covered by a fatty barrier
only fat soluble drugs can pass through the blood brain barrier T/F
true
can penicillin cross the blood brain barrier
no it is water soluble
Can fat soluble drugs cross the placental barrier
yes
Name 4 places that drugs can leave the body
kidneys, lungs, bile, skin
Define Drug Half Life
the amount of time for a drugs concentration in the blood to be reduced by half which gives you an idea of the duration of action of a medication in the body
define steady state
the amount you are taking in is balanced with the amount you are putting out
dehydration does not effect steady state T/F
false
drug effects are not changed by culture/ethnicity T/F
false, P-450 levels are different for different ethnicities
What percentage of medications do asians metabolize
70%
What percentage of medications do african americans metabolize
20-40%
what percentage of medications do caucasians metabolize
almost all medications
Medications that bond less to proteins are more effective T/F
true
