(Exam 2) Pharmacokinetics Flashcards
what is pharmacokinetics?
time course of a drug’s action
how much gets into the system, stays, and has effect
what does pharmacokinetics allow the determination of?
concentration of the drug at R, intensity of drug effect, and dosage
what does ADME stand for?
absorption, distribution, metabolism, and elimination
what is drug absorption?
movement of a drug from admin site to blood (across the BBB)
what does BBB stand for?
Blood-brain barrier
what is drug distribution?
where the drug goes - from blood to rest of the body, or where we want it to go
what is drug metabolism?
the breakdown of drug; takes place almost as soon as it gets into the body
what is drug elimination?
removal of drug metabolic waste products; once eliminated need a new dose
what are metabolites and what do they cause?
metabolites are waste products and can have their own effect aside from the drug
different ways to get a drug into the body?
IM, SC, TD, IV, TM, IH, and PO
IM and example
intramuscular; epi pen
SC and example
subcutaneous - under skin, but not into muscle; insulin, IVF
TD and example
transdermal; patch
IV and example
intravenous; shots
TM and example
transmembrane; under tongue
IH and example
inhalation; smoking, anesthesia, huffing
PO and example
per oral, pill
if something is considered a “systemic circulation location”, where are the drugs located?
blood, system
what is the ineffective range?
the range of dose/time where the drug doesn’t work
what is the therapeutic window?
the range of dose/time where the drug has the intended effect
what is the toxic range
the range of dose/time where the drug is toxic and can cause death or severe problems
what is the goal range?
therapeutic window
what does an enteral route mean?
goes through the GI tract
what does a parenteral route mean?
does not involve the GI tract
examples of enteral routes?
oral or rectal admin
why might drug companies try to do a parenteral route?
GI is a major hurdle; needs to survive after intestine metabolism, liver metabolism; not destroyed by stomach acid; and is affected by body weight and food intake
examples of parenteral routes
IV, IH, TM, TD
are parenteral or enteral route drugs “custom made”?
parenteral route drugs
what absorption method can be faster onset than IV?
IH
what is IH popularly used for?
recreational drugs
why is IH faster onset than IV?
goes to the lung tissue which has a large surface and is designed to absorb oxygen
TM can be absorbed through what face areas?
mouth or nose (across mucous membranes of nose)
examples of drugs absorbed through TM?
cocaine, nicotine replacements, fentanyl, morphine, suboxone
why is TM method better and used for nicotine replacements?
important to stop behavior of smoking (IH) and use a replacement method to subdue nicotine addiction
what does suboxone do in regards to addiction?
opiate agonist + antagonist combo; gives little for opiate craving, but also antagonist
how do patches work?
continuous, controlled release of drug; slow absorption (hours or days), + minimizes side effects
examples of TD absorption drugs
nicotine, fentanyl (for chronic pain), estrogen, scopalamine (motion sickness), selegilene (depression), methylphenidate (ADHD in children)
which is more dangerous: IV or IH? why?
IV; can circulate longer if not controlled; if ODing, IH + pass out = stop admin, IV = too late, already in system
IM absorption rate compared to PO and IV
faster than PO, slower than IV
IM typically injected into
arm/bicep, thigh
SC injected where?
under the skin (between skin + muscle)
is SC used often?
no; not easy to do; risk of damage to the skin
where is SC often used?
vet med - injected in scruff
animal research
what affects distribution?
membranes; cell membranes, capillary walls, BBB, placental “barrier”; system
what are capillary walls?
single layer of cells; extremely thin wall blood vessels; holes btwn cells
what typically moves through capillary walls?
nutrients, waste, + drugs
what doesn’t typically move through capillary walls?
RBCs (red blood cells) + large protein molecules bc they are too big
what is the purpose of the BBB?
protects neurons from toxins?
