Chapter 3

Question 1

Drug Therapy During Pregnancy

Answer 1

-Drugs cross the placenta by diffusion
-Factors affecting safety:
Drug properties
Fetal gestational age
Maternal factors
-FDA has implemented pregnancy safety categories

Question 2

Category A

Answer 2

Studies indicate no risk to the human fetus

Question 3

Category B

Answer 3

Studies indicate no risk to the animal fetus; info for humans is not available

Question 4

Category C

Answer 4

Adverse effects reported in the animal fetus; info for humans is not available

Question 5

Category D

Answer 5

Possible fetal risk in humans has been reported; however; in selected cases consideration of the potential benefit versus risk may warrant use of these drugs in pregnant women

Question 6

Category X

Answer 6

Fetal abnormalities have been reported, and positive evidence of fetal risk in humans is available from animal and/or human studies. These drugs are NOT to be used in pregnant women

Question 7

Drug transfer to the fetus is most likely to occur during what trimester?

Answer 7

last trimester

Question 8

Exposure of a fetus to drugs is most detrimental during what trimester?

Answer 8

first trimester

Question 9

fetuses are at greatest risk for drug-induced developmental defects during which trimester?

Answer 9

first trimester

Question 10

Drug Therapy During Breastfeeding

Answer 10

• Breastfed infants are at risk for exposure to drugs consumed by the mother
• Consider risk-to-benefit ratio

Question 11

Neonatal and Pediatric Considerations Absorption

Answer 11

Gastric pH less acidic until 1 to 2 years of age
Gastric emptying slowed
Intramuscular absorption faster and irregular

Question 12

Neonatal and Pediatric Considerations Distribution

Answer 12

• Greater total body water means lower fat content
• Decreased level of protein binding
• Immature blood–brain barrier—more drugs enter the brain

Question 13

Neonatal and Pediatric Considerations Metabolism

Answer 13

• Liver immature; does not produce enough microsomal enzymes

- Older children may have increased metabolism, requiring higher doses than infants

Question 14

Neonatal and Pediatric Considerations Excretion

Answer 14

• Kidney immaturity affects glomerular filtration rate and tubular secretion.
• Decreased perfusion rate of the kidneys may reduce excretion of drugs.

Question 15

Factors Affecting Pediatric Drug Dosages

Answer 15

• Skin is thin and permeable
• Stomach lacks acid to kill bacteria
• Lungs have weaker mucus barriers
• Body temperatures less well regulated, and dehydration occurs easily
• Liver and kidneys are immature, impairing drug metabolism and excretion

Question 16

Methods of Dosage Calculation for Pediatric Patients

Answer 16

-Body surface area method
      Uses the West nomogram
-Always use weight in kilograms, not pounds
-Always use centimeters, not inches
-Body weight dosage calculations
      Uses mg/kg

Question 17

Considerations for Older Adult Patients

Answer 17

• Older adults: older than age 65 years
• High use of medications
• Polypharmacy
• Noncompliance, nonadherence
• Increased incidence of chronic illnesses
• Sensory and motor deficits

Question 18

Older Adults Absorption

Answer 18

• Gastric pH less acidic
• Gastric emptying slowed
• Movement through GI tract slowed because of decreased muscle tone and activity
• Blood flow to GI tract reduced
• Absorptive surface of GI tract reduced

Question 19

Older Adults Distribution

Answer 19

• Lower total body water percentages
• Increased fat content
• Decreased production of proteins by the liver, resulting in decreased protein binding of drugs (and increased circulation of free drugs)

Question 20

Older Adults Metabolism

Answer 20

• Aging liver produces fewer microsomal enzymes, affecting drug metabolism
• Reduced blood flow to the liver

Question 21

Older Adults Excretion

Answer 21

Decreased glomerular filtration rate

Decreased number of nephrons