Perinatal and Pediatric Pharmacology

Question 1

drug administration to a pregnant patient can affect the developing fetus in one of two ways

Answer 1

• direct fetal effect

- indirect fetal effect

Question 2

direct fetal effect

Answer 2

passage into fetal circulation

Question 3

indirect fetal effect

Answer 3

changes in blood flow

Question 4

in pregnancy, most laws of pharmacodynamics and pharmacokinetics ____

Answer 4

still apply

Question 5

most drugs taken by pregnant women ____

Answer 5

can cross the placenta and expose the developing fetus to their effects

Question 6

drugs in maternal circulation can cross the placenta via:

Answer 6

• passive diffusion (majority)
• facilitated diffusion
• active transport
• pinocytosis/endocytosis

Question 7

drugs that are ____ will diffuse readily across the placenta

Answer 7

lipophilic

Question 8

highly ionized drugs cross the placenta ____;

____ concentrations in fetal circulation

Answer 8

slowly;

very low

Question 9

impermeability to polar compounds is ____ - if concentration gradient gets high enough, the drug may ____, even if it is ionized

Answer 9

relative;

pass readily

Question 10

lower molecular weight drugs pass _____ than larger drugs; there may be ____ that transport larger drugs (similar mechanism as transfer of maternal antibodies)

Answer 10

more readily;

placental transport proteins

Question 11

maternal blood has pH of ____ while fetal blood is ____; ____ is possible, especially if the fetus is “acidemic”

Answer 11

7.4; 7.3; ion trapping

Question 12

highly bound drugs may _____; exception is _____

Answer 12

have difficulty entering fetal circulation;

highly lipid-soluble drugs

Question 13

fetal proteins sometimes have ____ affinity for drugs; will be more highly bound in ____

Answer 13

lower;

maternal circulation that fetal (can have more active drug in fetal circulation than in maternal)

Question 14

effects of drugs on the pregnant female may be ____

Answer 14

altered (probably not significantly)

Question 15

pregnant female may require drugs that are ____

Answer 15

not needed otherwise (insulin, diuretics, etc.)

Question 16

fetus is sometimes the target for ____

Answer 16

therapeutic action

Question 17

predictable toxic drug actions

Answer 17

• dependence can develop in the fetus

- can cause organ damage

Question 18

a teratogenic drug must:

Answer 18

• result in characteristic malformation
• exert effects at a particular stage of development
• show dose-dependent incidence

Question 19

mechanisms of teratogenic drugs are ____

Answer 19

poorly understood; most likely multifactorial

Question 20

FDA risk category A

Answer 20

controlled studies fail to demonstrate risk in first trimester (and no evidence of later risk); safest category

Question 21

FDA risk category B

Answer 21

no risk in animal studies but no controlled human studies OR adverse effect shown in animal studies with no confirmation in human studies

Question 22

FDA risk category C

Answer 22

adverse effect shown in animal studies with no controlled human studies OR studies in women and animals are not available; only used if benefits to the mother outweigh the risks

Question 23

FDA risk category D

Answer 23

positive evidence of human fetal risk; only given in life-saving situations

Question 24

FDA risk category X

Answer 24

studies demonstrate fetal abnormalities; never given, no matter what

Question 25

new FDA ruling: narrative risk summary replaces single letter categories; subsections:

Answer 25

• pregnancy (summary of risk of taking medication while pregnant)
• lactation (summary of risk of taking medication while breast feeding)
• females and males of reproductive potential (summary of potential risk to developing fetus or to reproductive system)

Question 26

in infants and children, pharmacodynamic differences are ____

Answer 26

probably not significant;

except target tissues that mature at birth or shortly thereafter

Question 27

in infants and children, pharmacokinetic variables ____

Answer 27

change significantly in infants

Question 28

pharmacokinetic differences:

absorption

Answer 28

• blood flow at administration site (can be reduced in preterm infants)
• GI function (gastric acid secretion, gastric emptying time, and GI enzyme activity are all different; may require dose adjustments or changes to administration)

Question 29

pharmacokinetic differences:

distribution

Answer 29

body water percentage, fat composition, and plasma protein binding are different in infants

Question 30

pharmacokinetic differences:

metabolism

Answer 30

liver enzyme activity is lower in infants (individual enzymes take different lengths of time to mature)

Question 31

pharmacokinetic differences:

excretion

Answer 31

• lower glomerular filtration rate in newborns

- higher filtration rate in toddlers

Question 32

most drugs are excreted into breast milk, however ____

Answer 32

the concentrations are very small (below therapeutic levels)

Question 33

most drugs are excreted into breast milk in low concentrations;
exceptions:

Answer 33

• antibiotics
• sedatives and hypnotics
• opioids (complicated when mother taking methadone)

Question 34

dose recommendations usually found in ____

Answer 34

drug package insert, but often not for pediatric patients

Question 35

many drugs not _____ for pediatric use because ____

Answer 35

“approved”; no testing on infants and children

Question 36

when listed, the pediatric dose will usually be in ____

Answer 36

mg/kg or mg/pound; requires simple calculation

Question 37

if no recommended dose is listed, can use the following formula:

Answer 37

pediatric dose= adult dose x (weight (lbs)/150)