Flashcards in Exam 1; Metabolism and Excretion Deck (44)
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1
In general, the action of the drug is terminated by what
its metabolism
2
Which drugs are not terminated by its metabolism
prodrugs; they are inactive when given and are activated in the body
3
What are four sites of drug metabolism
skin
lungs
kidney
small intestine
4
What is the main organ (primary site) of drug metabolism
the liver
5
This is when an oral drug gets absorbed by the small intestine and travels to the liver via the portal system
first pass metabolism
6
If a drug is rapidly metabolized (nitroglycerin, morphine), it will not what
reach the circulation
7
The smooth endoplasmic reticulum of the liver cells contains a complex of enzymes referred to as what
cytochrome P450 (CYP)
8
What is the most significant form of CYP
CYP3A4; involved in more than 50% of the metabolism of drugs we talk about
9
CYPs catalyze what type of reactions
oxidation reactions
10
When CYP oxidizes a drug, what occurs?
the drug becomes more polar, which increases water solubility and makes it more readily excreted by the kidney
11
CYPs can be both induced and inhibited by what
environmental factors
12
What are some inhibitors of CYP
grapefruit juice
some antibacterials
some antifungals
13
What are some activators of CYP
phenytan and phenoharbitol
St. Johns
rifampin
14
What happens to the concentration of the drug upon inhibition or activation of CYP
inhibition of CYP = concentration of drug increases
activation of CYP = concentration of drug decreases
15
CYP450 is responsible for what percentage of phase 1 reactions
75%
16
Oxidation of the drug molecule forms what
a polar group like -OH or the removal of a non-polar group
17
This is the addition of -OH to a molecule
hydroxylation
18
What are four CYP450 phase 1 reactions besides hydroxylation
N-oxidation
S-oxidation
N-dealkylation
O-dealyklation
19
What are four non-CYP450 phase 1 reactions
deamination
hydrolysis; esterases
peptidases
phosphatases
20
What is the purpose of the phase II reactions
"finisher"
add a moiety to the drug (large molecule
21
What five endogenous molecule groups can be added to a drug during phase II
acetyl group
glucuronic acid
methyl group
sulfate grouo
amino acid (like glycine)
22
What is the primary organ of drug excretion
the kidney
23
The more polar molecules will or will not be excreted via the kidney
will
24
the more polar molecule will or will not stay in the urine and be excreted
will
25
The more non-ionized molecule will or will not be resorbed from urine
will
26
HA ⇆ H+ - A-
this means what
if you acidify the urine, this will allow the drug to stay in the body
27
In what other ways can the drugs be excreted
feces
lung
sweat
breast milk
28
What are three factors that can alter absorption
time of day; before during or after meals
age (older cannot metabolism as readily)
environment (other drugs taken)
29
What are three factors that can alter distribution of the drug in the body
body size and fat
gender
other drug interactions
30
