Exam 1: Chapter 2 Part 2 Flashcards
_______ means chemical alteration that occurs to a drug following administration or also called drug metabolism
biotransformation
What process alters the active form of the drug and can occur within minutes and the altered form will later be excreted
biotransformation
_____ means riding the body of the active and inactive form of a drug
excretion
Biotransformation is primarily a (liver/kidney) function
liver
Excretion is primarily a (liver/kidney) problem
kidney
How long does the excretion process take
hours, days, or weeks
With biotransformation, _____ within the tissues alter the drug’s structure which makes the compound (harmful/harmless)
enzymes, harmless
What is the altered form of the original compound that is readily excreted by the kidneys later. Usually this is no longer functional-it is inactive
metabolite
True or False
Although it is rare, some drugs are “prodrugs” and become functional after biotransformation
true
What is an example of a prodrug
Levodopa is inactive then after biotransformation it becomes active as dopamine to help treat Parkinson’s disease
Why is biotransformation/inactivation of a drug essential
Because the excretory rate is often too slow to rid the body of the original drug
(For example, anesthetics that lasted days or weeks)
In regards to the mechanism of drug biotransformation, the metabolite becomes ______ and thus more easily ionized and more (fat/water) soluble to be handled by the kidneys
polarized; water
Which organ is the primary site for drug metabolism that requires specific enzymes from this organ
the liver
List the 5 organs that are responsible for biotransformation
liver lungs kidneys GI epithelium skin
Explain the concept of tolerance to drugs
prolonged use of a drug can cause metabolic enzymes to become overly efficient making the drug less effective, which means a higher dose is required to get an effect.
True or False:
A damaged liver due to alcoholism will be able to metabolize drugs more efficiently due to a higher tolerance
False, if an organ is damaged, it won’t metabolize efficiently
The (liver/kidneys) are the primary site of drug excretion
kidneys
What is the name of the functional unit of the kidney
The nephron
How many nephrons are in a kidney
about 1 million
A metabolized drug reaches the nephron and is filtered at the _____ or _____ capsule. The filtrate then goes through the (proximal/distal) tubule, through the ____ of ____, then through the (proximal/distal) tubule before reaching the collecting duct.
glomerulus or Bowman’s capsule
proximal tubule
loop of henle
distal tubule
What happens if a drug is not reabsorbed back into the blood stream before reaching the collecting duct.
It will be released as urine
If a molecule is hydrophilic it is (polarized/nonpolar)
polarized
If a molecule is nonpolar it is a ____.
lipid
Does the drug excretion metabolism process tend to make polarized or non polarized soluble compounds
polarized water compounds
Polarized water soluble compounds remain _____ in the nephron so they can reach the collecting duct and be released into the urine
semi-trapped
explain how nonpolar lipophilic compounds are excreted
they are reabsorbed by the nephron back into circulation but a few reach the collecting duct
In regards to drug excretion, some drugs are secreted directly into the nephron at the level of the (proximal/distal) tubule via ____ ____
proximal tubule via active transport
Besides the kidney, list other routes of excretion
lungs, GI and liver to gall bladder, sweat, saliva, and breast milk
The lungs serve as a route of excretion for what type of drug
volatile drugs administered by inhalation
List the sequence of how the GI tract works with the liver and gall bladder to be a rout of excretion for drugs
From GI to liver to gallbladder where it becomes part of bile, then bile to bile duct, to duodenum, to feces
Sweat is a route of excretion for drugs because (tiny/large) amounts of drug metabolites as you sweat
tiny
Saliva is a route of excretion for drugs because (tiny/large) amounts of drug metabolites in the saliva which is why we can drug test using spit.
tiny
Explain why breast milk is a possible route of excretion for drugs
As milk comes out of the breast, the drugs come with it which could be dangerous in the baby’s first two months since they have not yet developed an ability to metabolize
_____ is the ability of all organs and tissues to eliminate the drug
clearance
A ___ - ___ is the amount of time required for 50% of the drug remaining in the body to be eliminated/cleared
half life
What is the half life of acetaminophen
2 hours
What does a drugs half life depend on
clearance and the presence of drug that is bound in the blood plasma
True or False:
Some drugs get sequestered in organs/tissues and are not available for clearance
true
How many half-lives are needed for the body to eliminate a drug
5
How many half-lives are needed to reach a steady state
5
What does a steady state of a drug mean
a point at which clearance and input are in dynamic equilibrium
Which type of administration allows for a steady state to be reaches easily
IV
If you wanted to achieve a steady state or a more consistent plasma concentration, would you choose smaller doses more frequently or larger doses over longer periods of time
small doses more frequently
List the factors that might cause two individuals to react differently to the same drug and same dosge
genetics, disease, drug interactions, age, diet, gender
Which age population are more sensitive to drugs
older patients and children
