Lecture 3 Flashcards
Rate of Absorption & Distribution: blood circulation throughout the body
- Entire volume of blood supply circulates every ____
Every minute
Rate of Absorption & Distribution: blood circulation throughout the body
_____ blood pumped every minute
5L/min blood pumped every minute
Administration: Intravenous
fastest b/c it goes straight into your bloodstream
and most dangerous
30-60 seconds
Administration: intraperitoneal
to your stomach (e.g., tubefeeding)
Administration: Subcutaneous
subcutaneous: into your fat
Administration: intracerebral
intracerebral: directly into your brain; bypass the blood-brain barrier; not really done in humans but on research animals
Administration: intracerebroventricular
intracerebroventricular: straight into CSF
Administration: oral
oral: one of the slowest ways; first pass metabolism (broken down in saliva, down to GI tract, etc); most common way for psychotherapeutic drugs
Administartion: Sublingual
sublingual: absorbing through capilaries below your tongue
*not same as oral
Admin: intrarecetal
intrarectal: bypassess “first pass” metabolism, straight up rectum
Admin: inhalation
inhalation: into your lungs
Admin: insufflation
insufflation: absorbed by the mucous membrane in your nose (e.g.,
snorting cocaine)
Admin: topical
Topical: on your skin
how long does intravenous take
30-60 seconds
Oral vs IM vs IV: blood concentration and time
Where do drugs exert their effects
Sites of action
Distribution: Entry of Drugs into the Brain –> where bind
- Drugs exert effects only at their sites of action
- Mostly on or in cells of the CNS
Distribution: Entry of Drugs into the Brain
What is the most important factor in determining the rate of distribution
Most important factor in determining the rate is lipid solubility
- Recall the BBB –> Lipid soluble materials pass through most rapidly
- Heroin > Morphine (heroin has higher level of lipid solubility, so it has a faster effects, so its more addictive)
What passes throgh the BBB
Lipid soluble
Water
Specialized sugars
check
Therapeutic Index
Commonly used margin of safety
Look at ratio between ED50 and TD50
Effective Dose 50 (ED50) = the dose that produces the desired effects in 50 percent of the individuals
Toxic Dose 50 (TD50) = the dose that produces toxic effects in 50 percent of the individuals
Therapeutic Index Desired Ratio
TI= TD50/ED50
WANT IT BIGGER THAN 10
(want toxic dose to be a lot bigger than effective dose)
Lower ratio is more dangerous (smaller margin of safety)
Most drugs affecting behavior affect…
Synaptic transmission (antagonist or agonist)
Agonist
Agonist a molecule that by binding to the receptor stimulates a
response = ↑ postsynaptic effects
Antagonists
Antagonists a molecule that by binding to a receptor blocks or
inhibits the response = ↓ postsynaptic effects
Addictive drugs more often agonist or antagonist
Agonist!
Addictive drugs (heroin, morphine, oxycodone) –> stimulation leads to “high”
Is botox an agonist or antagonist
antagonist!
Botulin poison causes paralysis by blocking release of acetylcholin.
wrinkles cannot form d/t the area being paralyzed
Antagonsit vs agonist
Agonist or Antagonist?
A drug that blocks the re-uptake or enzymatic degradation of a neurotransmitter?
Agonist
Your channels on neuron one are blocked, so you have a bunch of your transmitter in the cleft, and neuron 2 keeps firing. Since increasing firing in neuron 2, agonist
If the activation of a receptor causes vasoconstriction, what would
happen if someone took an antagonist for that receptor?
Decreases vasoconstriction
