Pediatrics

Question 1

Differences in Physiology Changes over ages

Answer 1

Body Water
Body Fat
Plasma Proteins
Hormones
Organ Function

Question 2

Neonates

Answer 2

Birth to 4 weeks

Question 3

Neonates
- Pre-Term

Answer 3

Gestational age < 37 weeks

Question 4

Neonates
- Full-term

Answer 4

39-40 weeks

Question 5

Neonates
- Post-term

Answer 5

Greater than 40 weeks

Question 6

Infants

Answer 6

1 to 12 months of age

Question 7

Child

Answer 7

1 to 12 years of age

Question 8

Adolescent

Answer 8

13 to 18 years of age

Question 9

Pediatric

Answer 9

Birth to 18 years of age

Question 10

Gestational Age

Answer 10

1st day of last period to birth

Question 11

PK Change Absorption
- Gastric pH

Answer 11

Neonates
- Pre-term: Little acid production
- Post-term: pH 6-8

Infants: Acid levels increase
Child: Acid levels may reach adult levels

Adolescent: Adult levels

Low gastric pH increases bioavailability of acidic drugs

Question 12

Gastric pH effect on acidic drugs

Answer 12

High gastric pH will decrease bioavailability of acidic drugs
- Acidic drug gets ionized and trapped in lipids

Low gastric pH will increase bioavailability of acidic drugs

Question 13

PK Changes Absorption
- Gastric Emptying

Answer 13

Infants: Reaches to adult levels at 6-8 months

Slow gastric emptying has various effects depending on the drug

Question 14

PK Changes Absorption
- Pancreatic Enzymes

Answer 14

Neonates: Low

Infants: Increases but still lower than adults

Child: Reaches adults level

Low levels = reduced absorption

Question 15

PK Changes Absorption
- GI Bacterial Colonization

Answer 15

Child: Normal adult levels by 4 years of age

Less bacteria = can not degrade medication effectively leading to high concentrations of drug

Question 16

PK Changes Absorption
- Drug transporters and metabolism enzymes

Answer 16

Pediatrics: Age-dependency is not clear yet

Higher bioavailability of drug in preterm neonates due to decreased expression of CPY3A4 in neonates

Question 17

PK Changes Distribution
- Total Body Water

Answer 17

Gradually decreases with age
- Reaches steady state at adult hood

Question 18

PK Changes Distribution
- Body Fat

Answer 18

1. Starts off small
2. Gradually increases
3. Peaks at 1 year
4. Gradually decreases

Question 19

PK Changes Distribution
- Intracellular Water

Answer 19

Does not really change

Question 20

PK Changes Distribution
- Extracellular Water

Answer 20

1. Starts off large
2. Gradually decreases
3. Reaches minimum at 6 months
4. Gradually increases

Question 21

PK Changes Distribution
- Hydrophobic Drugs

Answer 21

Hydrophobic drugs have a higher Vd in children than neonates

Question 22

PK Changes Distribution
- Albumin and Alpha1-acid glycoprotein

Answer 22

Decreased levels in infants
- Reach adult levels in 12 months

Question 23

PK Changes Distribution
- Bilirubin

Answer 23

Increased levels in neonates (Caused by low liver metabolism)
- Competes with drug binding to albumin

Question 24

PK Changes Distribution - Alpha-fetoprotein

Answer 24

The infant's proteins, Increased levels - Has decreased affinity for binding Eventually replaced by albumin in 3-4 weeks

Question 25

Acidic Drugs binding

Answer 25

They bind to albumin

Question 26

Basic Drugs binding

Answer 26

They bind to alpha1=acid glycoprotein

Question 27

PK Changes Excretion - Renal Clearance

Question 28

Dosing based on BW

Answer 28

Leads to understimation