Pediatric Developmental Pharmacology & Clinical PK Flashcards
Is percutaneous skin thick or thin in pre-term neonate
thinner
In percutaneous skin is perfusion greater or less in neonates
greater
in percutaneous skin is hydration greater or less in neonates
greater
In percutaneous skin is BSA greater or less in neonates?
greater
What are some potential implications of topically applied medications in neonates
increased absorption that leads to increase toxicity
How is water loss controlled or prevented?
- using a product that holds moisture in
- incubator (humidity control)
- IV fluids
T/F rectal absorption is not realiable
False, it is reliable because neonates cannot take a pill
what are the benefits of rectal absorption?
Increased bioavailability in neonates
- limited first pass metabolism
- decreased hepatic metabolism
What type of suppositories are best to give neonates?
quick melting suppositories
Why is IM absorption unpredictable?
- decreased muscle mass
- decreased muscle activity
- decreased blood flow
- increased capillary density
Why is it not good to give neonates rectal suppositories?
neonates have a pulsating rectum
What medications may be given IM to neonates
- Immunizations*
- aminoglycosides
- beta lactams
- palivizumab
what is the significance of intrapulmonary in neonates?
- lung architecture changes over time
2. majority as localized treatments
When are lungs fully developed in a pediatric patient?
7-8 years of age
Do medications administered via nebulizer or inhaler have systemic absorption?
yes
what are neonates pH at birth?
neutral (~7)
within 24-48h of birth what are neonates pH?
~1-3
during neonates first week of life what is there pH?
neutral
What are neonates gastrointestinal affected by?
- gastric pH
- biliary function
- motility
- gastric emptying
- surface area
- blood flow
What is gastric pH determined by?
- Solubility of medications
- Ionization of medications
- Stability of medications
Which gastric pH is more important in neonates
Stability
Is Vitamin D2 absorbed better in term neonates or preterm neonates
term
Why is there lower bile salts in GI biliary tract
- Decreased lipophilic medication absorption
2. Decreased lipid vehicle based medication absorption
When do villi mature
around 20 weeks gestation
if a patient is born at 23 weeks will they have more or less villi
less villi
when does gastric emptying increase in neonates
first week of life
when do neonates motility reach adult fucntion
around 6 months of life
Is there an increase or decrease in contractility in neonates
decrease
Is there a decrease or increase spread of medication to absorption sites in neonates
decrease
does blood flood increase or decrease with age ?
increase
does blood flow increase or decrease with feeding
increase
does the concentration gradient change with blood flow
yes
what percent of total body weight is water in preterm neonates
85%
what percent of total body weight is fat in preterm neonates
1%
What percent of total body weight is water in term neonates
75%
What percent of total body weight is fat in term neonates
15%
What percent of extracellular water is in neonates
40& of total body weight
what percent of extracellular water is in adults
20% of total body weight
Are hydrophilic medications higher or lower in neonates
higher
Are lipophilic meds typically lower or higher in neonates
lower
compare a neonate to an adult
- decreased plasma proteins
- lower binding capacity
- decreased affinity for medications
What are the implications of a neonate compared to an adult
- greater drug effect
- increased clearance
- greater toxicity risk
what are some examples of phase 1 enzymatic processes
- oxidation
- hydrolysis
- hydroxylation
- reduction
What percentage is CYP3A responsible for medication metabolism?
~50%
which CYP enzyme is the primary member until 6 months of age
3A7
when does CYP3A reach adult function
around 1 year of life
what are the substrates of CYP2C?
- 2C9
2. 2C19
How much is CYP2C responsible of medication metabolism
~20%
when does 2C9 reach adult function
5 months of age
when does 2C19 reach adult level
10 years of age
what does phase 2 of the enzymatic process consist of
- conjugation
- glucuronidation
- matures by 3 years of age
- exceeds adult function during childhood - sulfation
- matures at birth - alcohol dehydrogenase
- matures at 5 years of age - methylation
- infants, not adults
what does theophylline make in neonates
caffine
what are the 3 metabolism outcomes
- activating medication
- inactive medication
- form active metabolites
what is elimination affected by
- glomerular filtration
- tubular secretion
- tubular reabsorption
At what age does tubular secretion reach adult function
12 months of life
when does glomerular filtration increase
first 2 weeks of life
when does glomerular filtration reach adult function
8-12 months of life
how long is neonates serum creatinine equivalent to mothers
~ 1 week
what does k stand for in the GFR equation
age constant
what does L stand for in the GFR equation
length in cm
what does PCr = to? in the GFR equation
SCr
Does serum therapeutic concentrations of aminoglycosides and vancomycin, are they different from pediatrics, neonate, and adult, do they vary based on age?
No, they are the same
