Chapter 3 Lifespan Considerations
OBJECTIVES
When you reach the end of this chapter, you will be able to do the following:
1. Discuss the influences of the patient's age on the effects of drugs and drug responses.
2. Identify drug-related concerns during pregnancy and lactation and provide an explanation of the
physiologic basis for these concerns.
3. Summarize the impact of age-related physiologic changes on the pharmacokinetic aspects of drug
therapy.
4. Explain how these age-related changes in pharmacokinetics influence various drug effects and
drug responses across the lifespan.
5. Provide several examples of how age affects the absorption, distribution, metabolism, and
excretion of drugs.
6. Calculate a drug dose for a pediatric patient using the various formulas available.
7. Develop a nursing care plan for drug therapy and the nursing process as related to the various
lifespan considerations.
KEY TERMS
Active transport
The active (energy-requiring) movement of a substance between different tissues via pumping
mechanisms contained within cell membranes.
Diffusion
The passive movement of a substance (e.g., a drug) between different tissues from areas of higher
concentration to areas of lower concentration. (Compare with active transport.)
Neonate
Pertaining to a person younger than 1 month of age; newborn infant.
Older adult
Pertaining to a person who is 65 years of age or older. (Note: Some sources consider “older adult” to
be 55 years of age or older.)
Pediatric
Pertaining to a person who is 12 years of age or younger.
Polypharmacy
The use of many different drugs concurrently in treating a patient, who often has several health
problems.
Diffusuion
The passive movement of a substance between different tissues from areas of higher concentration
to areas of lower concentration
KEY POINTS:
• There are many age-related pharmacokinetic effects that lead to dramatic differences in drug
absorption, distribution, metabolism, and excretion in the young and the older adult. At one
end of the lifespan is the pediatric patient, and at the other end is the older adult patient, both of
whom are very sensitive to the effects of drugs.
• Most common dosage calculations use the milligrams per kilogram formula related to age. Organ
maturity may also be considered. It is important for the nurse to know that many elements besides the
mathematical calculation itself contribute to safe dosage calculations. Safety must remain the first
priority and concern with consideration of the Nine Rights of medication administration .
• The percentage of the population older than 65 years of age continues to grow, and polypharmacy
remains a concern with the increasing number of older adult patients. A current list of all medications
and drug allergies must be on their person or with their family/caregiver at all times.
• Your responsibility is to act as a patient advocate as well as to be informed about growth and
developmental principles and the effects of various drugs during the lifespan and in various phases of
illness.
Review Questions
1. The nurse is reviewing factors that influence pharmacokinetics in the neonatal patient. Which
factors puts the neonatal patient at risk with regard to drug therapy? (Select all that apply.)
a. Higher gastric pH
b. Increased peristalsis in the GI tract
c. Immature renal function
d. Reduced first-pass elimination in the liver
e. Decreased protein-binding of medications
2. The physiologic differences in the pediatric patient compared with the adult patient affect the
amount of drug needed to produce a therapeutic effect. The nurse is aware that one of the main
differences is that infants have which of these factors?
a. Increased protein in circulation
b. Fat composition lower than 0.001%
c. More muscular body composition
d. Water composition of approximately 75%
3. While teaching a 76-year-old patient about the adverse effects of his medications, the nurse
encourages him to keep a journal of the adverse effects he experiences. This
intervention is important for the older adult patient because of which alterations in pharmacokinetics?
a. Increased renal excretion of protein-bound drugs
b. More alkaline gastric pH, resulting in more adverse effects
c. Decreased blood flow to the liver, resulting in altered metabolism
d. Less adipose tissue to store fat-soluble drugs
4. When the nurse is reviewing a list of medications taken by an 88-year-old patient, the patient says,
“I get dizzy when I stand up.” She also states that she has nearly
fainted “a time or two” in the afternoons. Her systolic blood pressure drops 15 points when she stands
up. Which type of medication may be responsible for these effects?
a. Nonsteroidal antiinflammatory drugs (NSAIDs)
b. Cardiac glycosides
c. Anticoagulants
d. Antihypertensives
5. A pregnant patient who is at 32 weeks’ gestation has a cold and calls the office to ask about taking
an over-thecounter medication that is rated as pregnancy category Which answer by the nurse is
correct?
a. “This drug causes problems in the human fetus, so you should not take this medication.”
b. “This drug may cause problems in the human fetus, but nothing has been proven in clinical trials. It
is best not to take this medication.”
c. “This drug has not caused problems in animals, but no testing has been done in humans. It is
probably safe to take.”
d. “Studies indicate that there is no risk to the human fetus, so it is okay to take this medication as
directed if you need it.”
6. The nurse is preparing to administer an injection to a preschool-age child. Which approaches are
appropriate for this age group? (Select all that apply.)
a. Explain to the child in advance about the injection.
b. Provide a brief, concrete explanation about the injection.
c. Encourage participation in the procedure.
d. Make use of magical thinking.
e. Provide comfort measures after the injection.
7. The nurse is preparing to give an oral dose of acetaminophen (Tylenol) to a child who weighs 12
kg.The dose is 15 mg/kg. How many milligrams will the nurse administer for this dose?
8. An 82-year-old patient is admitted to the hospital after an episode of confusion at home. The nurse
is assessing the current medications he is taking at home. Which method is the best way to assess
his home medications?
a. Ask the patient what medications he takes at home.
b. Ask the patient's wife what medications he takes at home.
c. Ask the patient's wife to bring his medications to the hospital in their original containers.
d. Contact the patient's pharmacy for a list of the patient's current medications.