chapter 1
Introduction to Pharmacology
Objectives
AFTER STUDYING THIS CHAPTER, THE STUDENT WILL BE ABLE TO:
1. Differentiate between pharmacology and drug 7. Discuss nursing responsibilities in handling
therapy. controlled substances correctly.
2. Differentiate between generic and trade 8. Discuss the role of the Food and Drug
names of drugs. Administration.
3. Define a prototypical drug. 9. Analyze the potential impact of drug costs on
4. Select authoritative sources of drug information. drug therapy regimens.
5. Discuss major drug laws and standards. 10. Develop personal techniques for learning
6. Differentiate the main categories of con- about drugs and using drug knowledge in
trolled substances in relation to therapeutic client care.
use and potential for abuse.
Critical Thinking Scenario
This is your first semester of clinical nursing. This quarter you will be taking a basic nursing theory course, a
skills laboratory, and pharmacology. You anticipate that pharmacology will be challenging. To increase your
clinical knowledge and ensure that you will be a safe practitioner, you want to develop a strong foundation in
pharmacology.
Reflect on:
List successful strategies you have used in the past to learn difficult material. Reflect on which strategies
might be helpful this semester.
Assess support for your learning at your school (eg, learning center, peer tutors, student study groups)
and develop a plan to use them.
Review your course syllabus and pharmacology text. Develop a learning plan (eg, readings, assign-
ments, study times for major tests) and enter this plan into your calendar.
A MESSAGE TO STUDENTS this book is to help you learn about medicines and the why,
what, how, when, and where they are used in daily life. Bon
Y ou’ve probably been taking medicines and seeing other voyage!!
people take medicines most of your life. Perhaps you’ve given
medicines to your children, parents, grandparents, or others.
Have you ever wondered why it’s usually okay to give children OVERVIEW
Tylenol but not aspirin? Why a lot of middle-aged and older
people take an aspirin a day? Why people with high blood pres- Pharmacology is the study of drugs (chemicals) that alter
sure, heart failure, or diabetes take ACE inhibitors and what functions of living organisms. Drug therapy, also called
ACE inhibitors are? When an antibiotic should NOT be pre- pharmacotherapy, is the use of drugs to prevent, diagnose, or
scribed for an infection? treat signs, symptoms, and disease processes. When preven-
You are embarking on an exciting journey of discovery tion or cure is not a reasonable goal, relief of symptoms can
as you begin or continue your study of pharmacology. Much greatly improve quality of life and ability to function in ac-
of what you learn will apply to your personal and family life tivities of daily living. Drugs given for therapeutic purposes
as well as your professional life as a nurse. The purpose of are usually called medications.
2
, CHAPTER 1 INTRODUCTION TO PHARMACOLOGY 3
Medications may be given for various reasons. In many groups reflect their chemical characteristics rather than
instances, the goal of drug therapy is to lessen disease therapeutic uses (eg, adrenergics, antiadrenergics, benzo-
processes rather than cure them. To meet this goal, drugs diazepines). Many commonly used drugs fit into multiple
may be given for local or systemic effects. Drugs with local groups because they have wide-ranging effects on the human
effects, such as sunscreen lotions and local anesthetics, act body.
mainly at the site of application. Those with systemic effects Individual drugs that represent groups of drugs are called
are taken into the body, circulated through the bloodstream prototypes. Prototypes, which are often the first drug of a
to their sites of action in various body tissues, and eventu- particular group to be developed, are usually the standards
ally eliminated from the body. Most drugs are given for with which newer, similar drugs are compared. For example,
their systemic effects. Drugs may also be given for relatively morphine is the prototype of opioid analgesics; penicillin is
immediate effects (eg, in acute problems such as pain or in- the prototype of antibacterial drugs.
fection) or long-term effects (eg, to relieve signs and symp- Drug classifications and prototypes are quite stable, and
toms of chronic disorders). Many drugs are given for their most new drugs can be assigned to a group and compared
long-term effects. with an established prototype. However, some groups lack a
universally accepted prototype and some prototypes are re-
placed over time by newer, more commonly used drugs.
SOURCES OF DRUGS
Where do medications come from? Historically, drugs were DRUG NAMES
mainly derived from plants (eg, morphine), animals (eg, in-
sulin), and minerals (eg, iron). Now, most drugs are synthetic Individual drugs may have several different names, but the
chemical compounds manufactured in laboratories. Chemists, two most commonly used are the generic name and the trade
for example, can often create a useful new drug by altering the name (also called the brand or proprietary name). The generic
chemical structure of an existing drug (eg, adding, deleting, or name (eg, amoxicillin) is related to the chemical or offi-
altering a side-chain). Such techniques and other techno- cial name and is independent of the manufacturer. The generic
logic advances have enabled the production of new drugs as name often indicates the drug group (eg, drugs with generic
well as synthetic versions of many drugs originally derived names ending in “cillin” are penicillins). The trade name is
from plants and animals. Synthetic drugs are more standard- designated and patented by the manufacturer. For example,
ized in their chemical characteristics, more consistent in amoxicillin is manufactured by several pharmaceutical com-
their effects, and less likely to produce allergic reactions. panies, some of which assign a specific trade name (eg,
Semisynthetic drugs (eg, many antibiotics) are naturally oc- Amoxil, Trimox) and several of which use only the generic
curring substances that have been chemically modified. name. In drug literature, trade names are capitalized and
Biotechnology is also an important source of drugs. This generic names are lowercase unless in a list or at the begin-
process involves manipulating deoxyribonucleic acid (DNA) ning of a sentence. Drugs may be prescribed and dispensed by
and ribonucleic acid (RNA) and recombining genes into generic or trade name.
hybrid molecules that can be inserted into living organisms
(Escherichia coli bacteria are often used) and repeatedly re-
produced. Each hybrid molecule produces a genetically iden- DRUG MARKETING
tical molecule, called a clone. Cloning makes it possible to
identify the DNA sequence in a gene and produce the pro- A new drug is protected by patent for 14 years, during which
tein product encoded by a gene, including insulin and sev- it can be marketed only by the pharmaceutical manufacturer
eral other body proteins. Cloning also allows production of that developed it. This is seen as a return on the company’s
adequate amounts of the drug for therapeutic or research investment in developing a drug, which may require years of
purposes. work and millions of dollars, and an incentive for develop-
ing other drugs. Other pharmaceutical companies cannot
manufacture and market the drug. However, for new drugs
DRUG CLASSIFICATIONS that are popular and widely used, other companies often pro-
AND PROTOTYPES duce similar drugs, with different generic and trade names.
For example, the marketing of fluoxetine (Prozac) led to the
Drugs are classified according to their effects on particular introduction of similar drugs from different companies, such
body systems, their therapeutic uses, and their chemical as citalopram (Celexa), fluvoxamine (Luvox), paroxetine
characteristics. For example, morphine can be classified as (Paxil), and sertraline (Zoloft). Prozac was approved in 1987
a central nervous system depressant, a narcotic or opioid and went off patent in 2001, meaning that any pharmaceuti-
analgesic, and as an opiate (derived from opium). The names cal company could then manufacture and market the generic
of therapeutic classifications usually reflect the conditions for formulation of fluoxetine. Generic drugs are required to be
which the drugs are used (eg, antidepressants, antihyperten- therapeutically equivalent and are much less expensive than
sives, antidiabetic drugs). However, the names of many drug trade name drugs.
Introduction to Pharmacology
Objectives
AFTER STUDYING THIS CHAPTER, THE STUDENT WILL BE ABLE TO:
1. Differentiate between pharmacology and drug 7. Discuss nursing responsibilities in handling
therapy. controlled substances correctly.
2. Differentiate between generic and trade 8. Discuss the role of the Food and Drug
names of drugs. Administration.
3. Define a prototypical drug. 9. Analyze the potential impact of drug costs on
4. Select authoritative sources of drug information. drug therapy regimens.
5. Discuss major drug laws and standards. 10. Develop personal techniques for learning
6. Differentiate the main categories of con- about drugs and using drug knowledge in
trolled substances in relation to therapeutic client care.
use and potential for abuse.
Critical Thinking Scenario
This is your first semester of clinical nursing. This quarter you will be taking a basic nursing theory course, a
skills laboratory, and pharmacology. You anticipate that pharmacology will be challenging. To increase your
clinical knowledge and ensure that you will be a safe practitioner, you want to develop a strong foundation in
pharmacology.
Reflect on:
List successful strategies you have used in the past to learn difficult material. Reflect on which strategies
might be helpful this semester.
Assess support for your learning at your school (eg, learning center, peer tutors, student study groups)
and develop a plan to use them.
Review your course syllabus and pharmacology text. Develop a learning plan (eg, readings, assign-
ments, study times for major tests) and enter this plan into your calendar.
A MESSAGE TO STUDENTS this book is to help you learn about medicines and the why,
what, how, when, and where they are used in daily life. Bon
Y ou’ve probably been taking medicines and seeing other voyage!!
people take medicines most of your life. Perhaps you’ve given
medicines to your children, parents, grandparents, or others.
Have you ever wondered why it’s usually okay to give children OVERVIEW
Tylenol but not aspirin? Why a lot of middle-aged and older
people take an aspirin a day? Why people with high blood pres- Pharmacology is the study of drugs (chemicals) that alter
sure, heart failure, or diabetes take ACE inhibitors and what functions of living organisms. Drug therapy, also called
ACE inhibitors are? When an antibiotic should NOT be pre- pharmacotherapy, is the use of drugs to prevent, diagnose, or
scribed for an infection? treat signs, symptoms, and disease processes. When preven-
You are embarking on an exciting journey of discovery tion or cure is not a reasonable goal, relief of symptoms can
as you begin or continue your study of pharmacology. Much greatly improve quality of life and ability to function in ac-
of what you learn will apply to your personal and family life tivities of daily living. Drugs given for therapeutic purposes
as well as your professional life as a nurse. The purpose of are usually called medications.
2
, CHAPTER 1 INTRODUCTION TO PHARMACOLOGY 3
Medications may be given for various reasons. In many groups reflect their chemical characteristics rather than
instances, the goal of drug therapy is to lessen disease therapeutic uses (eg, adrenergics, antiadrenergics, benzo-
processes rather than cure them. To meet this goal, drugs diazepines). Many commonly used drugs fit into multiple
may be given for local or systemic effects. Drugs with local groups because they have wide-ranging effects on the human
effects, such as sunscreen lotions and local anesthetics, act body.
mainly at the site of application. Those with systemic effects Individual drugs that represent groups of drugs are called
are taken into the body, circulated through the bloodstream prototypes. Prototypes, which are often the first drug of a
to their sites of action in various body tissues, and eventu- particular group to be developed, are usually the standards
ally eliminated from the body. Most drugs are given for with which newer, similar drugs are compared. For example,
their systemic effects. Drugs may also be given for relatively morphine is the prototype of opioid analgesics; penicillin is
immediate effects (eg, in acute problems such as pain or in- the prototype of antibacterial drugs.
fection) or long-term effects (eg, to relieve signs and symp- Drug classifications and prototypes are quite stable, and
toms of chronic disorders). Many drugs are given for their most new drugs can be assigned to a group and compared
long-term effects. with an established prototype. However, some groups lack a
universally accepted prototype and some prototypes are re-
placed over time by newer, more commonly used drugs.
SOURCES OF DRUGS
Where do medications come from? Historically, drugs were DRUG NAMES
mainly derived from plants (eg, morphine), animals (eg, in-
sulin), and minerals (eg, iron). Now, most drugs are synthetic Individual drugs may have several different names, but the
chemical compounds manufactured in laboratories. Chemists, two most commonly used are the generic name and the trade
for example, can often create a useful new drug by altering the name (also called the brand or proprietary name). The generic
chemical structure of an existing drug (eg, adding, deleting, or name (eg, amoxicillin) is related to the chemical or offi-
altering a side-chain). Such techniques and other techno- cial name and is independent of the manufacturer. The generic
logic advances have enabled the production of new drugs as name often indicates the drug group (eg, drugs with generic
well as synthetic versions of many drugs originally derived names ending in “cillin” are penicillins). The trade name is
from plants and animals. Synthetic drugs are more standard- designated and patented by the manufacturer. For example,
ized in their chemical characteristics, more consistent in amoxicillin is manufactured by several pharmaceutical com-
their effects, and less likely to produce allergic reactions. panies, some of which assign a specific trade name (eg,
Semisynthetic drugs (eg, many antibiotics) are naturally oc- Amoxil, Trimox) and several of which use only the generic
curring substances that have been chemically modified. name. In drug literature, trade names are capitalized and
Biotechnology is also an important source of drugs. This generic names are lowercase unless in a list or at the begin-
process involves manipulating deoxyribonucleic acid (DNA) ning of a sentence. Drugs may be prescribed and dispensed by
and ribonucleic acid (RNA) and recombining genes into generic or trade name.
hybrid molecules that can be inserted into living organisms
(Escherichia coli bacteria are often used) and repeatedly re-
produced. Each hybrid molecule produces a genetically iden- DRUG MARKETING
tical molecule, called a clone. Cloning makes it possible to
identify the DNA sequence in a gene and produce the pro- A new drug is protected by patent for 14 years, during which
tein product encoded by a gene, including insulin and sev- it can be marketed only by the pharmaceutical manufacturer
eral other body proteins. Cloning also allows production of that developed it. This is seen as a return on the company’s
adequate amounts of the drug for therapeutic or research investment in developing a drug, which may require years of
purposes. work and millions of dollars, and an incentive for develop-
ing other drugs. Other pharmaceutical companies cannot
manufacture and market the drug. However, for new drugs
DRUG CLASSIFICATIONS that are popular and widely used, other companies often pro-
AND PROTOTYPES duce similar drugs, with different generic and trade names.
For example, the marketing of fluoxetine (Prozac) led to the
Drugs are classified according to their effects on particular introduction of similar drugs from different companies, such
body systems, their therapeutic uses, and their chemical as citalopram (Celexa), fluvoxamine (Luvox), paroxetine
characteristics. For example, morphine can be classified as (Paxil), and sertraline (Zoloft). Prozac was approved in 1987
a central nervous system depressant, a narcotic or opioid and went off patent in 2001, meaning that any pharmaceuti-
analgesic, and as an opiate (derived from opium). The names cal company could then manufacture and market the generic
of therapeutic classifications usually reflect the conditions for formulation of fluoxetine. Generic drugs are required to be
which the drugs are used (eg, antidepressants, antihyperten- therapeutically equivalent and are much less expensive than
sives, antidiabetic drugs). However, the names of many drug trade name drugs.
