introduction to pharmacokinetics 2

Question 1

where does the metabolism of a parent drug primarily occur

Answer 1

the liver

Question 2

clearance

Answer 2

Clearance describes the efficiency of irreversible elimination of the parent drug from the systemic circulation

Question 3

formula for clearance(CL)

Answer 3

Elimination rate/ Plasma drug concentration

Question 4

unit for clearance
unit for elimination rate
unit for plasma drug concentration

Answer 4

Lh^-1

mgh^-1

mgL^-1

Question 5

the total rate of elimination

Answer 5

the sum of all routes of elimination

Question 6

Xeno means?

Answer 6

foreign

Question 7

examples of drugs that could be considered xenobiotic

Answer 7

Pesticides
Environmental pollutants
Industrial Chemicals
Food additives

Question 8

which systems have the body evolved to rid itself of foreign substances

Answer 8

detoxification systems

Question 9

When the drug has been metabolized it is said to have been………… or ……………, even if it’s metabolites are still in the body

Answer 9

cleared or eliminated

Question 10

hepatic elimination

Answer 10

the process by which drugs and other foreign substances are modified, metabolized, and often detoxified by the liver (hepatic refers to the liver)

Question 11

the major organ containing the greatest abundance and diversity of drug-metabolizing enzymes

Answer 11

the liver

Question 12

why are lipophilic xenobiotics not excreted efficiently by the kidney?

Answer 12

Lipophilic (fat-soluble) xenobiotics are typically not efficiently excreted by the kidneys because the renal excretion process primarily favors water-soluble molecules. The kidneys filter and excrete substances from the bloodstream into the urine, and for a substance to be efficiently excreted, it must be water-soluble or must undergo specific processes to become more water-soluble

Question 13

lipophilic xenobiotics can only be excreted after being?

Answer 13

metabolized

Question 14

lipophilic xenobiotics are biotransformed into a new more polar entity called a

Answer 14

metabolite

Question 14

name given to the process by which lipophilic xenobiotics are converted to a form that can be excreted efficiently by the kidneys

Answer 14

biotransformation

Question 14

drug biotransformation can be classified into how many phases?
name them

Answer 14

2

phase I
phase II

Question 15

phase I metabolism

Answer 15

Introduction or unmasking of a chemically reactive functional group (increases the polarity of the compound)

Question 16

phase II metabolism

Answer 16

Conjugation of an endogenous molecule onto the functional group (further increases polarity of the compound)

Question 16

which one between phase I and II metabolism involves catabolic reactions

Answer 16

phase I

Question 17

which one between phase I and II metabolism involves anabolic reactions

Answer 17

phase II

Question 18

is the metabolite that phase II metabolism results in active?

Answer 18

no, they are inactive

Question 19

biliary elimination

Answer 19

is a process in which drugs, toxins, and waste products are excreted from the body via the bile produced by the liver

Question 20

major metabolising organ in mammals

Answer 20

liver

Question 21

do phase II reactions always follow phase I reactions

Answer 21

no

Question 22

when do phase II reactions happen immediately without phase I reactions

Answer 22

when the parent molecule contains reactive groups like hydroxyl groups, amino group…etc

Question 23

where do phase I reactions primarily occur

Answer 23

in the cytochrome P450 enzymes located in smooth endoplasmic reticulum membrane inside hepatocytes

Question 24

where do phase II reactions primarily occur

Answer 24

the hepatocyte cytosol

Question 25

in which organisms is Cytochrome P450 found, and in which tissues in these organisms can they be found

Answer 25

bacteria
plants
insects
mammals

virtually all tissues

Question 26

functional unit of the kidney

Answer 26

the nephron

Question 27

function of the nephron

Answer 27

to filter blood

Question 28

the three important processes that occur in the nephron that make up the renal clearance of a drug

Answer 28

filtration
secretion
reabsorption

Question 29

what are the undesired effects produced by a drug referred to as

Answer 29

adverse effects

Question 30

the therapeutic concentration of a drug is aka

Answer 30

Minimum effective concentration (MEC) of that drug

Question 31

the adverse concentration of a drug is aka

Answer 31

Minimum toxic concentration (MTC) of that drug

Question 32

the therapeutic range of a drug

Answer 32

difference between the MTC and the MEC

Question 33

purpose of the calculating the therapeutic range

Answer 33

Provides an indication of whether or not therapeutic drug monitoring is necessary

Question 34

is the true dose of the drug the amount of strength swallowed

Answer 34

no

Question 35

what is the true dose of a drug

Answer 35

amount available to have its effect

Question 36

examples of therapeutic windows

Answer 36

non toxic
medium toxicity
highly toxic

Question 37

difference between non toxic and highly toxic drugs

Answer 37

non toxic drugs have a large therapeutic window while toxic drugs have a narrow therapeutic window

Question 38

what does the true dose of a drug depend on

Answer 38

dissolution of the drug
absorption of the drug
the drugs ability to survive metabolism

Question 39

what could lead to reduced metabolism of a drug

Answer 39

Liver disease

Old age

Drug interactions

Inhibition of drug metabolising activities

Question 40

what could lead to increased metabolism of drugs

Answer 40

liver enzyme inductions

Question 41

formula for the rate of elimination

Answer 41

rate of renal excretion+ rate of hepatic metabolism

Question 42

drugs are less likely to be metabolised or eliminated when bound to other molecules, like proteins, true or false

Answer 42

true