NU 578
Unit 1 Study Guide
Key Concepts & Exam Review
University of South Alabama.
This document provides a focused
study guide
It summarizes key concepts, lecture highlights, and
exam-relevant material to support efficient last-
minute review. The guide is structured to help students reinforce
understanding, identify weak areas, and prepare confidently for
the assessment.
, CHAPTER 3
CONTROLLED SUBSTANCES – WHAT are the SCHEDULES and pp. 14 (10th ed)
HOW are they SET? key search term:
[CS2 drug is MORE addicting than CS3 drug] “1970 congress”
In 1970, Congress passed the Controlled Substances Act (Title II of the Comprehensive Drug Abuse Prevention and Control Act). This
legislation set rules for the manufacture and distribution of drugs considered to have the potential for abuse. One provision of the law
defines five categories of controlled substances, referred to as Schedules I, II, III, IV, and V.
• Schedule I: no accepted medical use in the US and deemed to have a high potential for abuse (heroin, mescaline, and lysergic acid
diethylamid (LSD)
• Schedules II through V: have accepted medical applications but also have a high potential for abuse (with the abuse potential
decreasing as you proceed from Schedule II to Schedule V)
CHAPTER 4
HOW and WHAT INFLUENCES DRUGS CROSSING MEMBRANES? pp. 25-28 (10th ed)
What do POLARITY and CHARGE (IONIZATION) have to do with drugs CROSSING key search term: “by
MEMBRANES or NOT CROSSING THEM? which drugs cross”
Three Ways to Cross a 1. Passage through channels or pores
Cell Membrane 2. Passage with the aid of a transport system
3. Direct penetration of the membrane itself (this is the is most common)
Very few drugs cross membranes via channels or pores
Channels and Pores • Membrane channels are extremely small (only the smallest compounds can pass through these
channels) and each channel is specific for certain molecules
• Potassium and sodium (small ions that have the ability to cross membranes via channels)
Transport systems are carriers that move drugs from one side of the cell membrane to the other (some require
the expenditure of energy to do this, while others do not)
Transport Systems All transport systems are selective à they will not carry just any drug
• Transport systems in the kidneys pump drugs from the blood into the renal tubules = allows for fast
renal excretion of many drugs
Movement of most drugs through the body is dependent on the ability to penetrate membranes directly due
to:
1. most drugs are too large to pass through channels or pores, AND
Direct Penetration of the 2. most drugs lack transport systems to help them cross all of the membranes that separate them from
Membrane their sites of action, metabolism, and excretion.
Membranes are composed primarily of lipids à to directly penetrate a membrane, a drug must be lipid
soluble (lipophilic)
• Polar molecules and ions: group of non-lipid soluble molecules à cannot penetrate membranes
Polar molecules with uneven distribution electrical charge à positive and negative charges within the
molecule tend to congregate separately from one another (i.e., water)
• Water (H2O): electrons (negative charges) in water molecule spend more time in the vicinity of the
oxygen atom (area tends to be negatively charged) vs. the vicinity of the two hydrogen atoms (area
tends to be positively charged)
• Gentamicin (Polar Drug): hydroxyl groups (attract electrons) give gentamicin its polar nature
Polar Molecules Most polar molecules have no net charge
• Polar molecules have an equal number of protons and electronsà positive and negative charges
balance each other exactly à molecule as a whole has neither a net positive charge nor a net negative
charge
• Polar molecules with a net charge à ions
“LIKE DISSOLVES LIKE”
• Polar molecules will dissolve in polar solvents (such as water) but not in nonpolar solvents (such as
oil).
• Polar drugs are unable to dissolve in the lipid bilayer of the cell membrane
Ions Molecules that have a net electrical charge (either positive or negative). Except for very small molecules, ions
are unable to cross membranes because they are not lipid-soluble.
, WHAT FACTORS affect the MAJOR PHARMACOKINETIC pp. 28-39 (10th ed)
PARAMETERS: Absorption, Distribution, Metabolism, and Excretion key search term: “rate
at which a drug”
There are four basic pharmacokinetic processes: absorption, distribution, metabolism, and excretion – working together, these determine
the concentration of a drug and its site of action
Dotted lines represent membranes that MUST be crossed as drugs move throughout the body
Rate of dissolution:
• drug formulation with rapid dissolution à faster onset
• drug formulation with slow dissolution à slower onset
Surface area: larger the surface area à faster the absorption (orally administered drugs are usually
ABSORPTION
absorbed from the small intestine due to extremely large surface area vs. the stomach)
Defined: the movement of Blood flow: high blood flow à rapid absorption of drugs (blood containing a newly absorbed drug will be
a drug from its site of rapidly replaced by drug-free blood à maintaining a large gradient between the concentration of drug outside
administration into the the blood and the concentration of drug in the blood)
body
Lipid solubility: highly lipid-soluble drugs à more rapidly absorbed vs. drugs whose lipid solubility is
The RATE of absorption low (due to the fact that lipid-soluble drugs can readily cross cell membranes)
determines how SOON
effects will begin pH partitioning: absorption will be enhanced when the difference between the pH of plasma and the pH
at the site of administration is such that drug molecules will have a greater tendency to be ionized in the
The AMOUNT of plasma
absorption helps determine • Ionization of drugs is pH dependent – when the pH of the fluid on one side of a membrane DIFFERS
how INTENSE effects will from the pH of the fluid on the other side, drug molecules will tend to accumulate on the side where
be the pH MOST FAVORS THEIR IONIZATION. When there is a pH gradient between two
sides of a membrane:
pp. 28 (10th ed) o Acidic drugs tend to ionize in basic media à acid drugs accumulate on alkaline side
o Basic drugs tend to ionize in acidic media à basic drugs will accumulate on acidic side
Example of ion trapping (pH partitioning): Poisoning – by manipulating urinary pH, we can employ ion
trapping to draw toxic substances from the blood into the urine, thereby accelerating their removal.
Two Groups of Route of Administration: enteral via
the GI tract (oral) AND parenteral via injection
(intravenous, subcutaneous, and intramuscular) à
route of drug affects onset and intensity of effects
, Determined by three major factors:
1. Blood flow to tissues (1st phase): drugs are carried by blood à tissues/organs of body; rate of delivery
to particular tissue is determined by blood flow to that tissue
a. As most tissues are well perfused, regional blood flow is rarely a limiting factor in drug
distribution
b. Two pathologic conditions (abscesses and solid tumors) have low regional blood flow à
conditions are resistant to drug therapy [limited blood flow is MAJOR reason why solid
tumors are resistant]
2. Ability of a drug to exit the vascular system (2nd phase): drug à organ/tissue via blood à exits
vasculature; IMPORTANT as it determines drug action and necessary for drugs to be metabolized
and excreted from the body
DISTRIBUTION a. Drugs in vascular system leave blood via capillary beds (drugs pass between capillary cells à
no resistance to departure of drugs à movement into the interstitial space)
Defined: drug movement b. The (BBB) blood-brain barrier is anatomy of capillaries (tight junctions between the cells that
from the blood to the compose the walls) in CNS
interstitial space of tissues i. to leave blood and reach sites of action within the brain, a drug must be able to pass
and from there into cells through cells of the capillary wall à ONLY drugs that are lipid soluble or have a
transport system can cross the BBB
ii. contains protective component P-glycoprotein (transporter that pumps drugs from
pp. 33-35 (10th ed)
CNS à back into blood)
iii. barrier protects brain from injury (toxic substances) – GOOD
iv. barrier can impede access of antibiotics to CNS infections – BAD
c. Protein binding of drugs: albumin is most prevalent protein in plasma and most important of
proteins to which drugs bind; only unbound (free) drug molecules can leave vascular system;
bound molecules are too large to fit through the pore in the capillary wall
3. Ability of a drug to enter cells (3rd phase): some drugs must enter cells to reach their sites of action
and most all drugs must enter cells to undergo metabolism and excretion
a. Lipid solubility and presence of a transport system (or both) determine the passage of drugs
across all membranes
b. Binding with receptors located on external surface of cell membrane à drugs produce effects
(these drugs DO NOT need to cross cell membrane to act)
Several factors influence the RATE drugs are metabolized:
1. Age: infants à drug-metabolizing capacity is limited (birth till 1 year, infants are sensitive to drugs due
to the liver not being fully developed to metabolize drugs until 1 year after birth). older adults à drug-
metabolizing capacity is decreased (drug dosages need to be reduced to prevent toxicity)
2. Induction and inhibition of drug-metabolizing enzymes: drugs may be P450 substrates, P450
enzyme inducers, and P450 enzyme inhibitors
3. First-pass effect: refers to the rapid hepatic inactivation of certain oral drugs
METABOLISM a. Drugs absorbed from GI tract à hepatic portal vein à carried directly to the liver
(biotransformation) i. Drugs that undergo rapid hepatic metabolism à inactivates drug completely on its
first pass through the liver à no therapeutic effects occur
Defined: the chemical ii. To circumvent the first-pass effect à drug is administered parenterally (allows the
alteration of drug structure drug to temporarily bypass the liver) à allows therapeutic drug levels in the systemic
circulation
Most metabolism occurs in b. Nitroglycerin (undergoes rapid hepatic metabolism) à administered SL nitro is very active as
the LIVER this permits drug absorption directly into systemic circulation à drug is carried to its site of
action (before passage through the liver) and therapeutic action can take place BEFORE the
pp. 35-37 (10th ed) drug is exposed to hepatic enzymes
4. Nutritional status: hepatic drug-metabolizing enzymes require a number of cofactors to function (i.e.,
malnourished patient: cofactors may be deficient à compromised drug metabolism)
5. Competition between drugs: two drugs metabolized by the same metabolic pathway à compete with
each other for metabolism à decrease the rate at which one or both agents are metabolized [severely
depressed metabolism = dangerous drug accumulation]
Factors That Modify Renal Drug Excretion:
1. pH-dependent ionization: used to accelerate renal excretion of drugs
a. Drugs that are ionized at the pH of tubular urine à remain in the tubule à excreted
b. Manipulating urinary pH (to promote ionization of a drug) à decrease passive reabsorption
back into the blood à increase rate of drug elimination
i. Aspirin poisoning (aspirin = acidic drug; acids tend to ionize in basic media):
elevation of urinary pH (make urine more basic) à more of the aspirin molecules in
Unit 1 Study Guide
Key Concepts & Exam Review
University of South Alabama.
This document provides a focused
study guide
It summarizes key concepts, lecture highlights, and
exam-relevant material to support efficient last-
minute review. The guide is structured to help students reinforce
understanding, identify weak areas, and prepare confidently for
the assessment.
, CHAPTER 3
CONTROLLED SUBSTANCES – WHAT are the SCHEDULES and pp. 14 (10th ed)
HOW are they SET? key search term:
[CS2 drug is MORE addicting than CS3 drug] “1970 congress”
In 1970, Congress passed the Controlled Substances Act (Title II of the Comprehensive Drug Abuse Prevention and Control Act). This
legislation set rules for the manufacture and distribution of drugs considered to have the potential for abuse. One provision of the law
defines five categories of controlled substances, referred to as Schedules I, II, III, IV, and V.
• Schedule I: no accepted medical use in the US and deemed to have a high potential for abuse (heroin, mescaline, and lysergic acid
diethylamid (LSD)
• Schedules II through V: have accepted medical applications but also have a high potential for abuse (with the abuse potential
decreasing as you proceed from Schedule II to Schedule V)
CHAPTER 4
HOW and WHAT INFLUENCES DRUGS CROSSING MEMBRANES? pp. 25-28 (10th ed)
What do POLARITY and CHARGE (IONIZATION) have to do with drugs CROSSING key search term: “by
MEMBRANES or NOT CROSSING THEM? which drugs cross”
Three Ways to Cross a 1. Passage through channels or pores
Cell Membrane 2. Passage with the aid of a transport system
3. Direct penetration of the membrane itself (this is the is most common)
Very few drugs cross membranes via channels or pores
Channels and Pores • Membrane channels are extremely small (only the smallest compounds can pass through these
channels) and each channel is specific for certain molecules
• Potassium and sodium (small ions that have the ability to cross membranes via channels)
Transport systems are carriers that move drugs from one side of the cell membrane to the other (some require
the expenditure of energy to do this, while others do not)
Transport Systems All transport systems are selective à they will not carry just any drug
• Transport systems in the kidneys pump drugs from the blood into the renal tubules = allows for fast
renal excretion of many drugs
Movement of most drugs through the body is dependent on the ability to penetrate membranes directly due
to:
1. most drugs are too large to pass through channels or pores, AND
Direct Penetration of the 2. most drugs lack transport systems to help them cross all of the membranes that separate them from
Membrane their sites of action, metabolism, and excretion.
Membranes are composed primarily of lipids à to directly penetrate a membrane, a drug must be lipid
soluble (lipophilic)
• Polar molecules and ions: group of non-lipid soluble molecules à cannot penetrate membranes
Polar molecules with uneven distribution electrical charge à positive and negative charges within the
molecule tend to congregate separately from one another (i.e., water)
• Water (H2O): electrons (negative charges) in water molecule spend more time in the vicinity of the
oxygen atom (area tends to be negatively charged) vs. the vicinity of the two hydrogen atoms (area
tends to be positively charged)
• Gentamicin (Polar Drug): hydroxyl groups (attract electrons) give gentamicin its polar nature
Polar Molecules Most polar molecules have no net charge
• Polar molecules have an equal number of protons and electronsà positive and negative charges
balance each other exactly à molecule as a whole has neither a net positive charge nor a net negative
charge
• Polar molecules with a net charge à ions
“LIKE DISSOLVES LIKE”
• Polar molecules will dissolve in polar solvents (such as water) but not in nonpolar solvents (such as
oil).
• Polar drugs are unable to dissolve in the lipid bilayer of the cell membrane
Ions Molecules that have a net electrical charge (either positive or negative). Except for very small molecules, ions
are unable to cross membranes because they are not lipid-soluble.
, WHAT FACTORS affect the MAJOR PHARMACOKINETIC pp. 28-39 (10th ed)
PARAMETERS: Absorption, Distribution, Metabolism, and Excretion key search term: “rate
at which a drug”
There are four basic pharmacokinetic processes: absorption, distribution, metabolism, and excretion – working together, these determine
the concentration of a drug and its site of action
Dotted lines represent membranes that MUST be crossed as drugs move throughout the body
Rate of dissolution:
• drug formulation with rapid dissolution à faster onset
• drug formulation with slow dissolution à slower onset
Surface area: larger the surface area à faster the absorption (orally administered drugs are usually
ABSORPTION
absorbed from the small intestine due to extremely large surface area vs. the stomach)
Defined: the movement of Blood flow: high blood flow à rapid absorption of drugs (blood containing a newly absorbed drug will be
a drug from its site of rapidly replaced by drug-free blood à maintaining a large gradient between the concentration of drug outside
administration into the the blood and the concentration of drug in the blood)
body
Lipid solubility: highly lipid-soluble drugs à more rapidly absorbed vs. drugs whose lipid solubility is
The RATE of absorption low (due to the fact that lipid-soluble drugs can readily cross cell membranes)
determines how SOON
effects will begin pH partitioning: absorption will be enhanced when the difference between the pH of plasma and the pH
at the site of administration is such that drug molecules will have a greater tendency to be ionized in the
The AMOUNT of plasma
absorption helps determine • Ionization of drugs is pH dependent – when the pH of the fluid on one side of a membrane DIFFERS
how INTENSE effects will from the pH of the fluid on the other side, drug molecules will tend to accumulate on the side where
be the pH MOST FAVORS THEIR IONIZATION. When there is a pH gradient between two
sides of a membrane:
pp. 28 (10th ed) o Acidic drugs tend to ionize in basic media à acid drugs accumulate on alkaline side
o Basic drugs tend to ionize in acidic media à basic drugs will accumulate on acidic side
Example of ion trapping (pH partitioning): Poisoning – by manipulating urinary pH, we can employ ion
trapping to draw toxic substances from the blood into the urine, thereby accelerating their removal.
Two Groups of Route of Administration: enteral via
the GI tract (oral) AND parenteral via injection
(intravenous, subcutaneous, and intramuscular) à
route of drug affects onset and intensity of effects
, Determined by three major factors:
1. Blood flow to tissues (1st phase): drugs are carried by blood à tissues/organs of body; rate of delivery
to particular tissue is determined by blood flow to that tissue
a. As most tissues are well perfused, regional blood flow is rarely a limiting factor in drug
distribution
b. Two pathologic conditions (abscesses and solid tumors) have low regional blood flow à
conditions are resistant to drug therapy [limited blood flow is MAJOR reason why solid
tumors are resistant]
2. Ability of a drug to exit the vascular system (2nd phase): drug à organ/tissue via blood à exits
vasculature; IMPORTANT as it determines drug action and necessary for drugs to be metabolized
and excreted from the body
DISTRIBUTION a. Drugs in vascular system leave blood via capillary beds (drugs pass between capillary cells à
no resistance to departure of drugs à movement into the interstitial space)
Defined: drug movement b. The (BBB) blood-brain barrier is anatomy of capillaries (tight junctions between the cells that
from the blood to the compose the walls) in CNS
interstitial space of tissues i. to leave blood and reach sites of action within the brain, a drug must be able to pass
and from there into cells through cells of the capillary wall à ONLY drugs that are lipid soluble or have a
transport system can cross the BBB
ii. contains protective component P-glycoprotein (transporter that pumps drugs from
pp. 33-35 (10th ed)
CNS à back into blood)
iii. barrier protects brain from injury (toxic substances) – GOOD
iv. barrier can impede access of antibiotics to CNS infections – BAD
c. Protein binding of drugs: albumin is most prevalent protein in plasma and most important of
proteins to which drugs bind; only unbound (free) drug molecules can leave vascular system;
bound molecules are too large to fit through the pore in the capillary wall
3. Ability of a drug to enter cells (3rd phase): some drugs must enter cells to reach their sites of action
and most all drugs must enter cells to undergo metabolism and excretion
a. Lipid solubility and presence of a transport system (or both) determine the passage of drugs
across all membranes
b. Binding with receptors located on external surface of cell membrane à drugs produce effects
(these drugs DO NOT need to cross cell membrane to act)
Several factors influence the RATE drugs are metabolized:
1. Age: infants à drug-metabolizing capacity is limited (birth till 1 year, infants are sensitive to drugs due
to the liver not being fully developed to metabolize drugs until 1 year after birth). older adults à drug-
metabolizing capacity is decreased (drug dosages need to be reduced to prevent toxicity)
2. Induction and inhibition of drug-metabolizing enzymes: drugs may be P450 substrates, P450
enzyme inducers, and P450 enzyme inhibitors
3. First-pass effect: refers to the rapid hepatic inactivation of certain oral drugs
METABOLISM a. Drugs absorbed from GI tract à hepatic portal vein à carried directly to the liver
(biotransformation) i. Drugs that undergo rapid hepatic metabolism à inactivates drug completely on its
first pass through the liver à no therapeutic effects occur
Defined: the chemical ii. To circumvent the first-pass effect à drug is administered parenterally (allows the
alteration of drug structure drug to temporarily bypass the liver) à allows therapeutic drug levels in the systemic
circulation
Most metabolism occurs in b. Nitroglycerin (undergoes rapid hepatic metabolism) à administered SL nitro is very active as
the LIVER this permits drug absorption directly into systemic circulation à drug is carried to its site of
action (before passage through the liver) and therapeutic action can take place BEFORE the
pp. 35-37 (10th ed) drug is exposed to hepatic enzymes
4. Nutritional status: hepatic drug-metabolizing enzymes require a number of cofactors to function (i.e.,
malnourished patient: cofactors may be deficient à compromised drug metabolism)
5. Competition between drugs: two drugs metabolized by the same metabolic pathway à compete with
each other for metabolism à decrease the rate at which one or both agents are metabolized [severely
depressed metabolism = dangerous drug accumulation]
Factors That Modify Renal Drug Excretion:
1. pH-dependent ionization: used to accelerate renal excretion of drugs
a. Drugs that are ionized at the pH of tubular urine à remain in the tubule à excreted
b. Manipulating urinary pH (to promote ionization of a drug) à decrease passive reabsorption
back into the blood à increase rate of drug elimination
i. Aspirin poisoning (aspirin = acidic drug; acids tend to ionize in basic media):
elevation of urinary pH (make urine more basic) à more of the aspirin molecules in
