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P A R T 1
Introduction to nursing pharmacology
History
The person’s history is an important element of
assessment related to drug therapy because their past
experiences and illnesses can influence a drug’s effect.
Knowledge of this important information before begin-
ning drug therapy will help to promote safe and effective
use of the drug and prevent adverse effects, clinically
important drug–drug, drug–food or drug–alternative
therapy interactions and medication errors. Relevant
aspects of the person’s history specifically related to
drug therapy are discussed in the following text.
Chronic conditions
Chronic conditions can affect the pharmacokinetics and
pharmacodynamics of a drug. For example, certain con-
ditions (e.g. renal disease, liver disease, heart disease,
diabetes, chronic lung disease) may be contraindications
to the use of a drug. In addition, these conditions may
require cautious use or dose adjustment when adminis-
tering a certain drug. For example, a person with renal
disease may require a decreased dose of a drug due to the
way the drug is eliminated. The nurse or midwife should
be aware of the person’s renal function to determine the
person’s ability to eliminate the drug. Therefore, if renal
disease is mentioned in the person’s history, the nurse or
midwife should consider this factor to evaluate the dose
of the drug that is prescribed.
Drug use
Prescription drugs, over-the-counter (OTC) drugs,
street drugs, alcohol, nicotine, alternative therapies
and caffeine may have an impact on a drug’s effect.
People often neglect to mention OTC drugs or alterna-
tive therapies because they do not consider them to be
actual drugs or they may be unwilling to admit their
use to the healthcare provider. Ask people specifically
about OTC drug or alternative therapy use. Drug–drug
interactions with OTC and prescribed drugs are highly
likely and can be dangerous, resulting in ineffective drug
therapy for some at-risk people. People might also forget
to mention prescription drugs that they routinely take,
for instance, oral contraceptives. Always ask specifically
about all types of medications that the person might use.
Allergies
A person’s history of allergies can affect drug therapy.
Past exposure to a drug or other allergens can provoke
a future reaction or necessitate the need for cautious use
of the drug, food or animal product. Obtain specific
information about the person’s allergic reaction to deter-
mine whether the person has experienced a true drug
allergy or was experiencing an actual effect or adverse
effect of the drug.
Level of education and understanding
Information about the person’s education level provides a
baseline from which the nurse or midwife can determine
the appropriate types of teaching information to use. A
person with a secondary school education may require
materials at a different level from the person with a uni-
versity degree. Gathering information about the person’s
level of understanding about their condition, illness or
drug therapy helps the healthcare provider to deter-
mine where the person is in terms of their status and
the level of explanation that will be required. It also
provides additional baseline information for developing
a person-focused education program. It is important
not to assume anything about the person’s ability to
understand based on their reported education level.
Stress, disease and environmental factors can all affect
a person’s learning readiness and ability. Direct assess-
ment of actual learning abilities is critical for good
education.
Social supports
People are being discharged from healthcare facilities
earlier than ever before, often with continuing care
needs. In addition, earlier discharges leave minimal time
for teaching. Often people need help at home with care
and drug therapy. A key aspect of discharge planning
involves determining what support, if any, is available to
the person at home. In many situations, it also involves
referral to appropriate community resources.
Financial supports
The high cost of healthcare in general, and of medica-
tions in particular, must be considered when initiating
drug therapy and promoting compliance. Financial con-
straints may cause a person not to follow through with a
prescribed drug regimen. For example, the drug may be
too expensive or the person may lack the means to get
to a pharmacy to obtain the drug. In some situations, a
less expensive drug might be appropriate in place of a
very expensive drug. In addition, the nurse or midwife
may need to refer the person to appropriate resources
that might offer financial assistance.
Pattern of healthcare
Knowing how a person seeks healthcare provides the
care provider with valuable information to include
when preparing the person’s teaching plan. Does this
person routinely seek follow-up care, or do they wait
for emergency situations? Does the person tend to self-
treat many complaints, or is every problem brought to
a healthcare provider? Information about patterns of
healthcare also provides insight into conditions that the
person may have but has not reported or medication use
that has not been stated.
Physical examination
It is important to assess the person’s physical status
before beginning drug therapy to determine if any
conditions exist that would be contraindications or
cautions for using the drug and to develop a baseline
