Drug Activity Flashcards
what are the 3 phases of drug activity
- pharmaceutic
- pharmacokinetic
- pharmcodynamic
what is the pharmaceutic phase
occurs after the drug is given and involves disintegration and dissolution of the dosage form
affected by form and route of administration
drug forms: aqueous
suspension, emulsion, syrup solution
can add flavors
drug forms: alcoholic
elixirs, spirits, tinctures
cough syrup
drug forms: lozenges/torches
dissolves in mouth
zinc/cough drops
drug forms: powders
drugs or drug extracts dried
compressed in tablets
drug forms: capsule
gelatin capsule filled with liquid or powder
drug forms: delayed-release
various coatings to release dose over period of time
drug forms: enteric coated
acid resistant coating
drug forms: suppositories
mixed with substance that melts at body temp (cocoa butter)
drug forms: ointments
soft, oily, semi solid containing drug applied to skin/eyes
drug forms: transdermal
drug embedded into bandage/patch
drug forms: parenteral injections
liquid or powder dissolved in sterile solution
drug forms: spray/mist
inhaled through nose/mouth
what is the pharmaco-kinetic phase
what the body does to the drug
ADME
ADME
adsorption
distribution
metabolism
excretion
drug absorption
passive diffusion (MC)
active transport
pinocytosis
filtraiton
drug ionization
impact absorption bc ionized molecules do not readily cross membranes
meds taken with milk do what
combat the acidity of the sotmach
acidic urine eliminates what
basic drugs
basic urine eliminates what
acidic drugs
type of drug that is lipid soluble and can cross membranes easily
anesthesia
Does food increase or decrease absorption
decrease
major sites of absorption
GI tract (MC), lungs, skin
Parenteral sites of absorption
intravenous, intramuscular, subcutaneous, intraperitoneal
MC type of absorption in GI tract
passive diffusion
type of absorption in lungs
passive diffusion
lipophilic (fat loving)
Type of absorption in skin
passive diffusion
a lot of variable factors
bio-availability
Once in the blood stream, drug is distributed to various tissue and organs
What is bio-availability dependent on
blood flow
plasma protein binding
presence of specific tissue barriers
selective distribution
what type of drug molecuels can exert a pharmacological effect
unbound (free)
What type of tissues see more drugs
ones with high blood flow
BBB
blood brain barrier
lipid barrier
only allows lipid substances in
placental barrier
some pass others don’t
what is selective distribution
an affinity, or attraction, of a drug to a specific organ or cells
why do we metabolize
makes us more polar/water soluble for urinary excretion
decreases half life
prevents accumulation
changes bio-avail
what do we need for metabolism
enzymes- drug microsomal metabolizing system
where are enzymes found
liver (MC)
kidneys
SI
Where are water soluble compounds excreted
kidney
first pass metabolism
after oral administration, all drugs are absorbed into the portal circulation
Transports the drugs to the livers before they are distributed throughout the body
Some drugs are metabolized significantly as they pass through the liver the first time
major site for excretion
urine (MC) bile lungs GI breast milk
minor sites for excretion
sweat
saliva
tears
semen
Where does filtration of blood occur
pores of glomerulus
When you’re 80 what is your clearance compared to a 30 year old
half of what is used to be
To make urine more acidic
vitamin C
to make urine more basic
sodium bicarbonate
how does active transport into bile occur
mostly fat-soluble molecules and end up in feces (saturated-liver
toxicity)
how do the lugs excrete compounds
passive diffusion of volatile metabolites from blood
how does the GI tract excrete compounds
passive diffusion of weak bases into intestinal lumen
how does breast milk excrete compounds
passive diffusion of fat soluble compounds
what is the pharmacodynamic phase
action of the drugs on living tissue
affected by form and route of administration
