NUR2474 Pharmacology Module 10 Quiz Review
Topics review:
1. Review timeframes for fetus development (trimesters), and which timeframes are most critical
a. Development:
i. Conception through week 2
ii. Embryonic period: weeks 3-8 (Gross malformations produced by teratogens)
iii. Fetal period: Week 9-delivery (functions disrupted with teratogen exposure
b. Third trimester: renal blood flow is doubled and renal excretion is accelerated
2. FDA Pregnancy Risk Categories
a. A: Safest
b. B: More dangerous than A
c. C: More dangerous than A and B
d. D: More dangerous than A, B, and C
e. X: Most dangerous; known to cause fetal harm
3. Alcohol effects on fetus development
a. Placental drug transfer
i. All drugs can cross the placenta
ii. Some can cross more easily than others
b. Adverse drug reactions during pregnancy
i. Can adversely affect both pregnant patient and fetus
ii. Some unique effects;
1. Heparin causes osteoporosis
2. Prostaglandins stimulate uterine contraction
3. Certain pain relievers used during delivery can depress
respiration in the neonate.
c. Birth defects
i. Gross malformations
1. Cleft palate, clubfoot, and hydrocephalus
ii. Neurobehavioral and metabolic anomalies
4. Lipid soluble drugs and placenta crossing
a. Placental drug transfer
i. All drugs can cross the placenta
ii. Some can cross more easily than others
b. Lipid soluble drugs (??)
i.
5. Treating asthma during pregnancy (med risk to fetus vs benefits) (??)
6. Chemo treatments in children (weight-based dosing) (I’m assuming this is what he meant.
Found on slide 19 & 20 of Chapter 10 PPT)
a. Dosing is most commonly based on body surface area
b. Initial pediatric dosing is, at best, an approximation
c. Subsequent doses need to be adjusted
d. Body surface are of the child x adult dose / 1.73 m2
, 7. Medication clearance children vs adults (not sure all of this is needed but just in case)
a. Pharmacokinetics: neonates and infants
i. Absorption
1. Oral administration: gastric emptying time is prolonged and
irregular. Adult function at 6-8 months.
2. Gastric acidity: very low 24 hours after birth. Does not reach adult
values for 2 years. Low acidity: absorption of acid-labile
drugs is increased.
3. Intramuscular administration: slow, erratic, delayed absorption as
a result of low blood flow during the first few days of life. During
early infancy, absorption of intramuscular drugs more rapid than
in neonates and adults.
4. Transdermal absorption: more rapid and complete for infants than
for older children and adults. Stratum corneum of infant’s skin is
very thin. Blood flow to skin greater in infants than in older patients.
Infants at increased risk of toxicity from topical drugs.
ii. Distribution
1. Protein binding: binding of drugs to albumin and other plasma proteins
is limited in the infant. Amount of serum albumin is relatively low.
2. Endogenous compounds compete with drugs for available binding
sites: limited drug/protein binding in infants. Reduced dosage
needed. Adult protein binding capacity by 10-12 months of age.
iii. Distribution: Blood-brain barrier
1. Not fully developed at birth
2. Drugs and other chemicals have relatively easy access to the CNS
3. Infants especially sensitive to drugs that affect CNS function
4. Dosage should also be reduced for drugs used for actions outside the CNS
if those drugs are capable of producing CNS toxicity as a side effect
iv. Hepatic metabolism
1. The drug-metabolizing capacity of newborns is low
2. Neonates are especially sensitive to drugs that are eliminated
primarily by hepatic metabolism
3. The liver’s capacity to metabolize many drugs increases rapidly
about 1 month after birth
4. The ability to metabolize drugs at the adult level is reached
a few months later
5. Complete liver maturation occurs by 1 year of age.
v. Renal excretion
1. Significantly reduced at birth.
2. Low renal blood flow, glomerular filtration, and active tubular secretion
3. Drugs eliminated primarily by renal excretion must be given in
reduced dosage and/or at longer dosing intervals
4. Adult levels of renal function achieved by 1 year.
Topics review:
1. Review timeframes for fetus development (trimesters), and which timeframes are most critical
a. Development:
i. Conception through week 2
ii. Embryonic period: weeks 3-8 (Gross malformations produced by teratogens)
iii. Fetal period: Week 9-delivery (functions disrupted with teratogen exposure
b. Third trimester: renal blood flow is doubled and renal excretion is accelerated
2. FDA Pregnancy Risk Categories
a. A: Safest
b. B: More dangerous than A
c. C: More dangerous than A and B
d. D: More dangerous than A, B, and C
e. X: Most dangerous; known to cause fetal harm
3. Alcohol effects on fetus development
a. Placental drug transfer
i. All drugs can cross the placenta
ii. Some can cross more easily than others
b. Adverse drug reactions during pregnancy
i. Can adversely affect both pregnant patient and fetus
ii. Some unique effects;
1. Heparin causes osteoporosis
2. Prostaglandins stimulate uterine contraction
3. Certain pain relievers used during delivery can depress
respiration in the neonate.
c. Birth defects
i. Gross malformations
1. Cleft palate, clubfoot, and hydrocephalus
ii. Neurobehavioral and metabolic anomalies
4. Lipid soluble drugs and placenta crossing
a. Placental drug transfer
i. All drugs can cross the placenta
ii. Some can cross more easily than others
b. Lipid soluble drugs (??)
i.
5. Treating asthma during pregnancy (med risk to fetus vs benefits) (??)
6. Chemo treatments in children (weight-based dosing) (I’m assuming this is what he meant.
Found on slide 19 & 20 of Chapter 10 PPT)
a. Dosing is most commonly based on body surface area
b. Initial pediatric dosing is, at best, an approximation
c. Subsequent doses need to be adjusted
d. Body surface are of the child x adult dose / 1.73 m2
, 7. Medication clearance children vs adults (not sure all of this is needed but just in case)
a. Pharmacokinetics: neonates and infants
i. Absorption
1. Oral administration: gastric emptying time is prolonged and
irregular. Adult function at 6-8 months.
2. Gastric acidity: very low 24 hours after birth. Does not reach adult
values for 2 years. Low acidity: absorption of acid-labile
drugs is increased.
3. Intramuscular administration: slow, erratic, delayed absorption as
a result of low blood flow during the first few days of life. During
early infancy, absorption of intramuscular drugs more rapid than
in neonates and adults.
4. Transdermal absorption: more rapid and complete for infants than
for older children and adults. Stratum corneum of infant’s skin is
very thin. Blood flow to skin greater in infants than in older patients.
Infants at increased risk of toxicity from topical drugs.
ii. Distribution
1. Protein binding: binding of drugs to albumin and other plasma proteins
is limited in the infant. Amount of serum albumin is relatively low.
2. Endogenous compounds compete with drugs for available binding
sites: limited drug/protein binding in infants. Reduced dosage
needed. Adult protein binding capacity by 10-12 months of age.
iii. Distribution: Blood-brain barrier
1. Not fully developed at birth
2. Drugs and other chemicals have relatively easy access to the CNS
3. Infants especially sensitive to drugs that affect CNS function
4. Dosage should also be reduced for drugs used for actions outside the CNS
if those drugs are capable of producing CNS toxicity as a side effect
iv. Hepatic metabolism
1. The drug-metabolizing capacity of newborns is low
2. Neonates are especially sensitive to drugs that are eliminated
primarily by hepatic metabolism
3. The liver’s capacity to metabolize many drugs increases rapidly
about 1 month after birth
4. The ability to metabolize drugs at the adult level is reached
a few months later
5. Complete liver maturation occurs by 1 year of age.
v. Renal excretion
1. Significantly reduced at birth.
2. Low renal blood flow, glomerular filtration, and active tubular secretion
3. Drugs eliminated primarily by renal excretion must be given in
reduced dosage and/or at longer dosing intervals
4. Adult levels of renal function achieved by 1 year.
