NURS 572 Study Questions & answers Latest Update
2026.
ADME
Absorption
Distribution
Metabolism
Excretion
first-pass metabolism
Metabolism by the liver following oral administration is called first-pass metabolism and is
important determining if drugs can be given orally
when drug is partially broken down by the liver (and sometimes the intestinal wall) before
it reaches the bloodstream
Example: oral medication--> intestine--> liver checkpoint--> blood stream (liver takes away
some of the drug before it can circulate)
memory trick for first pass effect
first trip through the liver
First order kinetics
Reaction rate is directly proportional to substrate concentration
,rate depends directly on the concentration
related to drug concentration so that a fixed fraction of the drug is metabolized per hour
Zero Order kinetics
A constant amount of a substance is processed or eliminated per unit of time, regardless of its
concentration
metabolize a constant amount of drug per hour
first-order kinetics example
If there are 100 mg in the body and 10% is eliminated each hour:
Hour 1: 100 mg → 90 mg
Hour 2: 90 mg → 81 mg
Hour 3: 81 mg → 72.9 mg
A constant percentage is eliminated over time.
zero order kinetics example
If the body eliminates 10 mg per hour:
Hour 1: 100 mg → 90 mg
Hour 2: 90 mg → 80 mg
Hour 3: 80 mg → 70 mg
A constant amount is eliminated each hour.
Phase I metabolism
, -nonsynthetic reactions
-involves oxidation, reduction, and hydrolysis reactions
-introduce or unmask polar groups that generally improve water solubility and prepare drug
molecules for further metabolic reactions
-can result in metabolites with greater or lesser pharmacological activity
-Many phase I metabolites are rapidly eliminated, and others go to phase II reactions
Phase II metabolism
-synthetic or conjugation reactions
-drug molecules are metabolized and something is added to the drug to synthesize a new
compound
-metabolites are linked or conjugated to highly polar molecules such as glucoronic acid, glycine,
sulfate, or acetate by specific enzymes
-conjugation of these molecules makes metabolites more water-soluble and more easily excreted
by the kidneys, so the presence or activity of these enzymes can influence the patter of drug
activity and the duration of action for drugs
Phase I metabolism easily explained
modify the drug
oxidation, reducation, hydrolysis*
Drug has been changed
phase II metabolism easily explained
attach (conjugate) something to drug to make it more water soluble
drug is tagged for elimination
2026.
ADME
Absorption
Distribution
Metabolism
Excretion
first-pass metabolism
Metabolism by the liver following oral administration is called first-pass metabolism and is
important determining if drugs can be given orally
when drug is partially broken down by the liver (and sometimes the intestinal wall) before
it reaches the bloodstream
Example: oral medication--> intestine--> liver checkpoint--> blood stream (liver takes away
some of the drug before it can circulate)
memory trick for first pass effect
first trip through the liver
First order kinetics
Reaction rate is directly proportional to substrate concentration
,rate depends directly on the concentration
related to drug concentration so that a fixed fraction of the drug is metabolized per hour
Zero Order kinetics
A constant amount of a substance is processed or eliminated per unit of time, regardless of its
concentration
metabolize a constant amount of drug per hour
first-order kinetics example
If there are 100 mg in the body and 10% is eliminated each hour:
Hour 1: 100 mg → 90 mg
Hour 2: 90 mg → 81 mg
Hour 3: 81 mg → 72.9 mg
A constant percentage is eliminated over time.
zero order kinetics example
If the body eliminates 10 mg per hour:
Hour 1: 100 mg → 90 mg
Hour 2: 90 mg → 80 mg
Hour 3: 80 mg → 70 mg
A constant amount is eliminated each hour.
Phase I metabolism
, -nonsynthetic reactions
-involves oxidation, reduction, and hydrolysis reactions
-introduce or unmask polar groups that generally improve water solubility and prepare drug
molecules for further metabolic reactions
-can result in metabolites with greater or lesser pharmacological activity
-Many phase I metabolites are rapidly eliminated, and others go to phase II reactions
Phase II metabolism
-synthetic or conjugation reactions
-drug molecules are metabolized and something is added to the drug to synthesize a new
compound
-metabolites are linked or conjugated to highly polar molecules such as glucoronic acid, glycine,
sulfate, or acetate by specific enzymes
-conjugation of these molecules makes metabolites more water-soluble and more easily excreted
by the kidneys, so the presence or activity of these enzymes can influence the patter of drug
activity and the duration of action for drugs
Phase I metabolism easily explained
modify the drug
oxidation, reducation, hydrolysis*
Drug has been changed
phase II metabolism easily explained
attach (conjugate) something to drug to make it more water soluble
drug is tagged for elimination
