viii
Preface
Part 3
focuses on drugs affecting the immune
system, because recent knowledge about the immune
system has made it the cornerstone of modern therapy.
All of the immune system drugs act in ways in which the
immune system would act if it were able. Recent immu-
nological research has contributed to a much greater
understanding of this system, making it important to
position information about drugs affecting this system
close to the beginning of the text instead of at the end,
as has been the custom.
Parts 4 and 5
address drugs that affect the nervous
system, the basic functioning system of the body.
Following the discussion of the nervous system, and
closely linked with it in
Part 6
, is the endocrine system.
The sequence of these parts introduces students to
the concept of control, teaches them about the inter
relatedness of these two systems and prepares them for
understanding many aspects of shared physiological
function and the inevitable linking of the two systems
into one: the neuro-endocrine system.
Parts 7, 8 and 9
discuss drugs affecting the repro-
ductive, cardiovascular and renal systems, respectively.
The sequencing of cardiovascular and renal drugs is
logical because most of the augmenting cardiovascular
drugs, such as diuretics, affect the renal system.
Part 10
covers drugs that act on the respiratory
system, which provides the link between the left and
right ventricles of the heart.
Part 11
addresses drugs acting on the gastrointes-
tinal system. The gastrointestinal system stands on its
own; it does not share any actions with any other system.
FEATURES OF THIS EDITION
The text’s features are skilfully designed to support the
text discussion, encouraging the student to look at the
whole person and to focus on the essential informa-
tion about each drug class. Important features focus on
incorporating basic clinical skills, person safety, critical
thinking and application of the material learned to the
clinical scenario, helping the student to understand
the pharmacology material.
Chapter structure
Each chapter opens with a list of
learning objectives
for
that chapter, helping the student to understand what the
key learning points will be.
Learning objectives
Upon completion of this chapter, you should be able to:
1.
Define the word pharmacology.
2.
Outline the steps involved in developing and approving a new drug in Australia and New Zealand.
3.
Describe the legislative controls on drugs that have abuse potential.
4.
Differentiate between generic and brand-name drugs, over-the-counter and prescription drugs.
5.
Explain the benefits and risks associated with the use of over-the-counter drugs.
Introduction to drugs
1
Chapter openings also include a
glossary of key
terms
and a
list of featured drugs
.
Glossary of key terms
adverse effects:
drug effects that are not the desired therapeutic effects; may be unple
brand name:
name given to a drug by the pharmaceutical company that developed it;
chemical name:
name that reflects the chemical structure of a drug
drugs:
chemicals that are introduced into the body to bring about some sort of change
generic drugs:
drugs sold by their chemical name; not brand (or trade) name products
generic name:
the original designation that a drug is given when the drug company th
genetic engineering:
process of altering DNA, usually of bacteria, to produce a chemic
New Zealand Medicines and Medical Devices Safety Authority (MEDSAFE):
a busine
authority responsible for the regulation of therapeutic products in New Zealand
orphan drugs:
drugs that have been discovered but would not be profitable for a drug
treat only a small number of people; these orphans can be adopted by drug compani
over-the-counter (OTC) drugs:
drugs that are available without a prescription for self-tr
be safe when used as directed
pharmacology:
the study of the biological effects of chemicals
pharmacotherapeutics:
clinical pharmacology—the branch of pharmacology that deal
medicine for the treatment, prevention and diagnosis of disease in humans
phase I study:
a pilot study of a potential drug conducted with a small number of select
phase II study:
a clinical study of a proposed drug by selected doctors using actual peo
to treat; the subjects must provide informed consent
phase III study:
use of a proposed drug on a wide scale in the clinical setting with peopl
to treat
phase IV study:
continual evaluation of a drug after it has been released for marketing
post-marketing surveillance:
monitoring the safety of medicines and medical devices i
preclinical trials:
initial trial of a chemical thought to have therapeutic potential; uses la
teratogenic:
having adverse effects on the fetus
Therapeutic Goods Administration (TGA):
Australian commonwealth government ag
enforcement of drug evaluation and distribution policies
Test your current knowledge of drugs with a PrepU Practice Quiz!
Glossary of key terms
azoles:
a group of drugs used to treat fungal infections
Candida
:
fungus that is normally found on mucous membranes; can cause yeast infection
immunosuppressed individuals
ergosterol:
steroid-type protein found in the cell embrane of fungi; similar in c nfigurat
fungus:
a cellular organism with a hard cell wall that contains chitin and many polysaccha
contains rgosterols
mycosis:
disease ca sed by a fungus
tin a:
fungus called ringworm that causes such infections as at l te’s foot, jo k itch and o
Test your current knowledge of antifungal agents with a PrepU Practice Quiz!
SYSTEMIC ANTIFUNGALS
Azole antifungals
fluconazole
itraconazole
ketoconazole
posaconazole
terbi afine
voriconazole
Echinocandin antifungals
anidulafungin
caspofungin
Other antifungals
amphotericin B
flucytosine
griseofulvin
nystatin
TOPICAL ANTIFUNG
Azole topical antifu
butoconazole
clotrimazole
econazole
ket conazole
iconazole
terbinafine
Key poin s
appear pe iodically throughout each
chapter to summarise important concepts.
C H A P T E R 1
Introduction to drugs
5
pigs. Now
genetic engineering
—the process of altering
DNA—permits scientists to produce human insulin
by altering
Escherichia coli
bacteria, making insulin a
better product without some of the impurities that come
with animal products.
Thyroid drugs and growth hormone preparations
also may be obtained from animal thyroid and hypo-
thalamic tissues. Many of these preparations are now
created synthetically, however, and the synthetic
prep rations are considered to be purer and safer than
preparations derived from animals.
Inorganic compounds
Salts of various chemical elements can have therapeu-
tic effects in the hum body. Aluminium, fluoride, iron
and even gold are used to treat various conditions. The
effects of these elements were usually discovered acci-
dentally when a cause–effect relationship was observed.
Table 1.2 shows examples of some elements used for
their therapeutic eff cts.
Synthetic sources
Today, many drugs are developed sy thetically after
chemicals in plants, animals or the environment have
been tested and found to have therapeutic activity. Scien-
tists use genetic engineering to alter bacteria to produce
chemicals that are therapeutic and effective. Other tech-
nical advances allow scientists to alter a chemical with
proven therapeutic effectiveness to make it better. Some-
times, a small change in a chemical’s structure can make
that chemical more useful as a drug—more potent, more
stable, less toxic. These techn l gic l advances have
led to the development of groups o si il r drugs, all
of which are derived from an original prototype, but
each of which has slightly different properties, making
a particular drug more desirable in a specific situa-
tion. hroughout this book, the icon
will be used
to desig ate those drugs of a class that are considered
the prototype of the class, the original drug in the class
or the drug that has emerged as the most effective.
For example, the cephalosporins are a large group of
antibiotics derived from the same chemical structure.
Alterations in th ch mical ri gs or attachments to that
structure m ke it possible for some of these drugs to
be absorbed orally, whereas others must e given par-
enterally. Some of these drugs cause severe toxic effects
(e.g. renal tox city), but others do not.
KEY POINTS
■■
Clinical pharmacology is he s udy of drugs used to
treat, diagno e or preven a disease.
■■
Drugs are chemicals that are introd ced into the
body and affect the body’s chemical processes.
■■
Drugs can come from plants, foods, animals, salts of
inorganic compounds or synthetic sources.
DRUG EVALUATION
After a chemical that might have therapeutic value is
identified, it must undergo a series of scientific tests to
evaluate its actual therapeutic and toxic effects. This
process is tightly controlled by the
Therapeutic Goods
Administration (TGA)
, an agency of the Australian
Department of Health and Ageing that regulates the
development and sale of drugs. TGA-regulated tests are
designed to ensure the safety and reliability of any drug
approved in this country. For every 100,000 chemicals
that are identified as being potential drugs, only about
five end up being marketed. Before receiving final TGA
KEY POINTS
■■
TABLE 1.1 Drugs derived from plants
Plant
Product
Ricinus c mmunis
Seed
Oil
Castor oil (Neolid)
Digitalis p rpurea
(foxglove plant)
Leaves
Dried leaves
Digitalis leaf
Papaver somniferum
(poppy plant)
Unripe capsule
Juice
Opium
Morphine (MS Contin,
Ordine)
Codeine
Papaverine
■■
TABLE 1.2 Elements us d for their therapeu ic
effects
Element
Therapeutic use
Aluminium Antacid to decrease gastric acidity
Management of
hyperphosphataemia
Prevention of the formation of
pho ph te urinary stones
Fluorine
(as fluoride)
Prev nti n of dental cavities
Prevention of osteoporosis
Gold
Treatment of rheumatoid arthritis
Iron
Treatment of iron deficiency anaemia
■■
TABLE 1.3 Comparison of generic, chemical, and brand names of drugs
thyroxine sodium
←
generic name
→
poractant alfa
l
-thyroxine,T
4
←
chemical name
→
dipalmitoylphosphatidylcholine
Eut oxsig, Oroxine
←
brand names
→
Curosurf
The text of each chapter ends with a
summary of
important concepts
.
12
P A R T 1
Introduction to nursing pharmacology
Therapeutic Guideli es
provides a wid rang of
drug i formation a series of systematic guid s, such
as tibiotics and astrointestinal pharmacology. These
guidelines draw upon a range of evaluated literature and
research.
McKenna’s Drug Handbook for Nursing and Mid-
wifery
has drug monographs organised alphabetically
and includes care implications and important teaching
points specifically relevant to nursing and midwifery
practice.
Numerous other drug handbooks are also on the
market and readily available for nurs s and midwives
to use.
Journals
Various journals can be us d to obtain drug informa-
tion. For example, the
Medical Letter
is a monthly
review of new drugs, drug classes and sp cific treat-
ment protocols. Many clinical nursing and midwifery
journals
offer information on new drugs, drug errors
and care implications.
Australian Prescriber
is a useful
source of easily interpreted pharmacology information
and is freely available online.
Internet information
Many individuals now use the Internet as a source of
medical information and advice. Nur es and midwives
need t become familiar with w a is available on the
Internet and what people may be referencing, and have
skills in critiquing the credibility of these sources.
CHAPTER SUMMARY
■■
Drugs are chemicals that are intro uced into the
body to bring about some sort of chang .
■■
Drugs can come from many sources: plants, animals,
inorganic elements nd synthetic prepar tions.
■■
Th TGA regulates the development and marketing
of drugs
safety and efficacy in Australia.
■■
Preclinical trial involve testing of potential drugs on
laboratory an mals to determine their therapeutic and
adverse effects.
■■
Phase I studies test potential drugs on healthy human
subjects.
■■
Phase II studies test potential drugs on individuals
who have the disease the drugs are designed to treat.
■■
Phase III studies test dr gs in the clinical setting
to determine any unanticipated effects or lack of
effectiveness.
■■
TGA pregnancy categories indicate the potential or
actual teratogenic effects of a drug.
■■
Generic drugs are sold under their chemical names,
not brand names; they may be cheaper but are not
necessarily as safe as brand-name drugs.
■■
Orpha drug
discov red to
are not financ
drugs.
■■
OTC drugs a
self-treatment
■■
Information a
variety of sou
books, journ
Knowi
study m
to find o
ONLIN
An extensive rang
and learning and t
b found online at
thePoint at http://
Learn videos, Con
review questions,
WEB LI
Healthcare pro
the following In
Home page of t
Product Agency
Australian Pres
Home page of
Home page of
Service.
Home page of t
BIBLIOGRA
Barton, J. H. & Em
pharmaceutical
potential refor
Cardinale, V. (199
directions.
Dru
Davies, C. A. (200
of the regulatio
devices in Austr
Dempsey, J., Hilleg
Nursing and Mi
(2nd Australian
Williams & Wil
This is followed by a series of review exercises in the
Check your understanding
s ction, to h lp focus student
learning on the s minal i formatio presented in the
chapter. This section assists students in testing their
knowledge and preparing for examinations.
928
P A R T 1 1
Drugs acting on the gastrointestinal system
Paul, S. P., Dewdney, C. & Lam, C. (2012). Managing children
with constipation in the community.
Nurse Prescribing, 10(6)
,
274–284.
Porth, C. M. (2011).
Essentials of Pathophysiology: Concepts
of Altered Health States
(3rd edn). Philadelphia: Lippincott
Williams & Wilkins.
Porth, C. M. (2009).
Pathophysiology: Concepts of Altered Health
States
(8th edn). Philadelphia: Lippincott Williams & Wilkins.
Prynn, P. (2011). Managing adult constipation.
Practice Nurse,
41(17)
, 23–28.
Sarre, R. (2005). Bowel pre aration.
Australian P escriber, 28
, 16–17.
Selby, W. (2010). Ma
Prescriber, 33
, 11
Shah, S. B. & Hanauer, S. B. (2007). Treat
pat ents w th inflammatory bowel diseas
Reviews in Gastroenterology Disorders,
Tobias, N., Mason, D., Lutkenhoff, M., Sto
(2008). Management and principles of o
childhood constipation.
Journal of Pedi
12–23.
Wang, M., Szucs, T. D. & Steffen, R. (2008
traveler’s diarrhea.
Journ l of Travel Me
C H E C K Y O U R U N D E R S T A N D I N G
C
U
Answers to the questions in this chapter can be found in
Appendix A at the back of this book.
MULTIPLE CHOICE
Select the best response to the following.
1.
Laxatives are drugs that are used to:
a.
increase the quantity of wastes excreted.
b.
speed the passage of the intestinal contents
through the GI tract.
c.
increase digestion of intestinal contents.
d.
increase the water content of the intestinal
contents.
2.
The laxative of choice when mild stimulation is
needed to prevent straining is:
a.
senna.
b.
castor oil.
c.
bisacodyl.
d.
magnesium sulphate.
3.
Cathartic dependence can occur when:
a.
people do not use laxatives routinely and
MULTIPLE RESPONSE
Select all that apply.
1.
A nurse or midwife is preparing
a person who has been prescribe
teaching plan should include wh
a.
the importance of proper diet
b.
the need to take the drug for
the full effect
c.
the importance of exercise
d.
the need to take advantage of
by providing privacy and tim
to work
e.
the need to limit fluids
f.
the importance of limiting th
laxative use
2.
A nurse or midwife might expec
paraffin for which person?
a.
a debilitated person low on n
b.
a person with haemorrhoids
c.
a person with recent rectal su
