Chapter 4 Pharmacology and the Care of the Infant

1. A pediatric nurse is well aware of the many physiological variables that influence safe pharmacotherapy in patients younger than 18. Which of the following principles should the nurse integrate into care?

1. A)  The physiology of patients older than 15 can be considered to be the same as an

   adult patient.

2. B)  The younger the patient, the greater the variation in medication action compared

   to an adult.

3. C)  The larger the patient’s body mass index, the more his or her physiology varies

   from that of an adult.

4. D)  Pediatric patients have a greater potential to benefit from pharmacotherapy than

   adult patients.

Ans: B

Feedback:

The younger the patient, the greater the variation in medication action when compared to an adult. This does not necessarily equate into a greater potential for benefit, however. BMI is not the main or sole basis of variations between adults and children.

2. An infant who is 3 weeks old was born at full gestation but was just brought to the emergency department with signs and symptoms of failure to thrive. This pediatric patient will be classified into what pediatric age group?

1. A)  Full-term baby
2. B)  Young infant
3. C)  Neonate
4. D)  Early postnatal

Ans: C

Feedback:

Neonates are considered to be infants from full-term newborn 0 to 4 weeks of age.

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3. A pediatric nurse practitioner is aware that there are many knowledge gaps that still exist in the evidence base that underlies pediatric pharmacology. Many of these knowledge gaps are rooted in

1. A)  a lack of scientific understanding of the anatomy and physiology of children and

   infants.

2. B)  the historical lack of pediatric participation in the drug testing process.
3. C)  the fact that research grants in pharmacology have traditionally specified adult

   participation.

4. D)  assumptions that there are no physiological differences between adults and

   children.

Ans: B

Feedback:

Historically, researchers used only adults to test medications, and prescribers simply assumed that smaller doses would elicit the same results in smaller patients. The knowledge base surrounding anatomical and physiological differences between adults and children is substantial, and grant funding is not typically limited to adult participation.

4. A 3-year-old Asian American boy has had culture and sensitivity testing performed, and antibiotic treatment is indicated. The prescriber knows that the recommended antibiotic has not been extensively studied in pediatric patients. Consequently, the prescriber will be obliged to do which of the following?

A)

B) C) D)

Ans:

Administer subtherapeutic doses in order to mitigate the potential for adverse effects
Choose a different antibiotic that has been extensively tested in children
Apply vigilant clinical judgment when administering the antibiotic to the child Have the child’s family sign informed consent forms absolving the care team from responsibility for adverse effects

C

Feedback:

Prescribers must continue to treat pediatric patients with drugs for which they lack information; therefore, they must practice good assessment, dosing, and evaluation during the administration of any medication to a pediatric patient. Alternative drugs are not always an option, and a lack of data does not absolve the care team from responsibility for adverse outcomes.

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5. A 9-year-old boy with severe influenza symptoms will be treated with ribavirin (Rebetol), an antiviral that is usually taken by adults twice daily in doses of 600 mg PO. After learning that the child’s body surface area (BSA) is 1.10, the nurse will anticipate that the child will likely receive how much ribavirin for each dose?

1. A)  110 mg
2. B)  380 mg
3. C)  545 mg
4. D)  660 mg

Ans: B
Feedback:
The prescriber calculates a dose based on a known adult dose by using the following equation: pediatric dose = BSA/1.73 × adult dose. Thus, 1.1  1.73 × 600 = 381.5 mg. This would likely be rounded to 380 mg.

6. Significant pharmacodynamic variations exist between adult patients and pediatric patients. Which of the following factors are known to contribute to differences in the ways that drugs affect target cells in children and infants? Select all that apply.

1. A)  Inability of children to accurately describe adverse effects
2. B)  Immaturity of children’s organ systems
3. C)  Differences in the body composition of children
4. D)  The lack of active immunity in children
5. E)  Differences in the function of humoral immunity in children

Ans: B, C
Feedback:
Immature organ systems and changing body compositions mean that drugs affect children differently. Causes of pharmacodynamic variability across the lifespan include differences in body composition, immature systems, and genetic makeup. Total body water, fat stores, and protein amounts change throughout childhood and greatly influence the effectiveness of drugs in the pediatric population. Children are indeed less able to describe adverse effects, but this is not a pharmacodynamics variation. Differences in the function of the immune system are not noted to significantly influence pharmacodynamics.

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