Exam 2 Flashcards
(156 cards)
what is the liver the main site for?
site of metabolism of nutrients (phase 1&2 of biotransformation)
-DETOXIFICTATION
-1st pass metabolism occurs here
what does 1st pass metabolism occur through in the liver?
through hepatic portal vein
-GI –> Liver
what type of enzymes does the liver contain to help maintain homeostasis?
microsomal enzymes
what do microsomal enzymes do?
-all-purpose binding sites (can bind several molecules in binding sites, not specific)
what family are the microsomal enzymes in the liver apart of?
cytochrome 450 super family
-over 50 different types
what does the cytochrome 450 family do?
oxidized psychoactive drugs in phase 1 of biotransformation
-antidepressants, morphine
what is enzyme induction?
creation of MORE enzymes to reestablish homeostasis
-with repeated use, it increases enzyme synthesis
-can be effected by diet
what type of food can create enzyme induction?
brussel sprouts
what is enzyme inhibition?
things that LESSEN the effectiveness of the enzyme
-decrease metabolism
-creates more ‘free’ drug
-can be effected by diet
what type of food can create enzyme inhibition?
grapefruit
which can contribute to tolerance, enzyme inhibition or enzyme induction?
enzyme induction
what is drug competition?
multiple drugs ‘fight’ for same sites and increase drug effects
-more ‘free’ drug
what do the kidneys do?
filters blood and removes toxins as urine (pH 4.5 - 7.5)
what is required for biotransformation and ion-trapping to occur in the kidneys?
ionization
what does the Koryak tribesman w/ Amanita muscaria mushroom proove?
proves that you can feel the effects of the drug a second time after being excreted as urine
how can ‘free’ drug stop someone from smoking?
when the compounds aren’t ionized (can be done through diet), the nicotine keeps circulating as the ‘free’ drug
-you don’t feel the effects but the drug is still circulating, lessening the cravings
-stress can stop the ‘free’ drug from being free and increase cravings
what does ADH (antiduretic hormone) do and what is a common every-day example with ADH?
inhibits excretion of water
-alc and caffeine INHIBIT ADH causing you to pee more and become dehydrated
how else can a drug be excreted besides through the kidneys?
-lungs (breathing alc)
-breast milk (acidic so it ion traps alkaloids)
-skin
-salvia
-bile in feces
what is the general relationship between dose and effects?
increasing dose, increases effects
-only to a max, then it decrease due to toxicity
-deals with pharmacodynamics (drug interaction w/ target)
what are 3 common factors that can impact the dose and effect relationship?
size/weight
pharmacokinetics
pharmacodynamics
how does pharmacokinetics impact the dose and effect relationship?
-protein binding
-cyt 450 differences
-acetylation in phase 2 (rats > humans > dogs)
-conjugation in phase 2 (humans > cats)
how does pharmacodynamics impact the does and effect relationship?
-NT and receptor distributions vary
how does weight impact the dose and effect relationship?
-amount of drug per body weight (mg/kg)
-how much it takes to achieve equal blood conc/
what does an effective dose produce?
produces a biological response