1
Q
Define preterm, neonate, infant, child and adolescent?
A
- preterm: under 36 weeks gestational age
- neonate: first 30 days of life
- infant: 1 month to 1 year
- child: 1 -12 years old
- adolescent: 12-18 years old
2
Q
Variables affect GI absorption of meds?
A
- pH
- gastric emptying time and GI motility
- pancreatic enzyme activity
- GI surface area
- intestinal microorganisms
3
Q
Diff in pH?
A
- more alkaline than adults until child reaches 1
- adversely affects absorption of weakly acid drugs and improves absorption of weakly basic drugs
4
Q
Diff in gastric emptying time and GI motility?
A
- slower than adults for first month of life
- neonates and infants have irregular peristalsis
(can increase absorption)
5
Q
Diff in pancreatic enzyme activity?
A
- decreased for first year of life compared to adults
- affects drugs that are fat soluble (not absorbed)
- neonates can’t absorb vitamin E
6
Q
Diff in GI surface area?
A
- intestinal size relatively to body size matters
- in young kids - relative size of duodenum compared with adults enhances drug absorption
7
Q
Diff in GI microorganisms?
A
- intestinal flora depends more on diet than age
- more rapid development of flora in breast fed infants
- flora is active in breakdown of various drugs
- example: digoxin is reduced to inactive metabolites by anaerobic intestinal bacteria. Digoxin metabolites are not detected in kids until about 16 months of age and adult like reduction of digoxin doesn’t occur until age 9
- warfarin same thing
8
Q
When is rectal absorption used? How are drugs absorbed?
A
- for pts who can’t tolerate oral drugs or lack IV access
- drug is absorbed by hemorrhoidal veins and avoids first pass hepatic metabolism
- most drugs admin by this route are erratically and incompletely absorbed
- ex: Diazepam, valproic acid or secobarbital may be given PR in status epilepticus when lacking IV access
- babies have a lot of BMs, that are unpredictable, and they also don’t have good anal sphincter tone - PR isn’t the best route!
9
Q
IM absorption - what is it affected by? How does it differ in neonates and infants?
A
- affected by muscle mass, blood flow to muscle, tone and activity
- neonates: decreased muscle mass and limited muscle activity decreases blood flow to and from the muscle, erratic and poor drug absorption
- infants: greater density of skeletal muscle capillaries than older children therefore more efficient absorption
10
Q
How is percutaneous absorption affected?
A
- by thickness of the skin
- body surface area relative to body mass
- neonates have thin skin and increased BSA relative to body mass = sig percutaneous drug absorption in neonates compared to adults
- Be careful with ointments and creams!!
11
Q
Factors affecting distribution in ped patients?
A
- vascular perfusion
- body composition
- tissue binding characteristics
- physiochemical properties of the drug
- plasma protein binding
- route of administration
- neonates: these factors are sig different from adults
12
Q
Vascular perfusion in babies?
A
- changes in perfusion are common in neonates
- ex: in response to hypoxia the blood may be diverted (shunted) from the lungs to the tissues and organs
(inhaled meds - low deposition rate in lungs)
13
Q
Body composition in babies?
A
- higher the total body water and extracellular water the larger the volume of distribution
- neonates and infants have increased total body water and ECF compared to older children and adults
- neonates: mostly water, drugs will be more diluted
14
Q
Tissue binding characteristics?
A
- drugs bound to tissue exhibit increased free blood levels when mass of tissue is reduced such as in peds
15
Q
Physiochemical properties?
A
- lipid solubility
- molecular configuration
- these properties affect the ability of the drug to move across membranes into target tissues and cells
- regarding percutaneous absorption, may lead to toxicity in the neonate
16
Q
Plasma protein binding in babies?
A
- neonates have decreased alpha 1-acid glycoprotein - binds alkaline drugs
- decreased albumin in neonates: binds acid drugs, fatty acids, and bilirubin
- results in drug displacement and increased plasma levels due to decreased available protein for binding
- larger Vd in neonates compared to adults
17
Q
Route of admin - distribution sites?
A
- orally:
liver becomes the primary distribution site, affected by hepatic first pass metabolism, oral doses are generally higher than IV doses - IV: heart and lungs act as the primary method of distribution
18
Q
Distribution difference in babies and adults - ECF?
A
- adults: 20% body wt is ECF
- neonates: 40% of body wt is ECF
- drugs that are distributed mainly in ECF (ahminoglycosides)
- Vd should reflect ECF compartment of patient
- neonates reqr higher dosage of amingoglycosides
19
Q
Difference in protein binding in neonates - increased volume of distribution effects what drugs?
A
- theophylline
- ampicillin
- phenobarbital
- phenytoin
20
Q
Tissue uptake in neonates, drugs that have increased uptake and Vd?
A
- morphine
- fentanyl
- digoxin
21
Q
Drug metabolism in peds?
A
- delayed in neonates, infants and young kids
- drug clearance is reliant on hepatic metabolism
- phase 1 (oxidation, reduction, hydrolysis):
CYP 450 system is decreased in neonates (ex: caffeine and theophylline (need smaller doses and less frequent dosing) - increased in infants and children: anticonvulsants (6 mo - 2 yrs) often 2-5x adult dose
- phase 2 conjugation: acetaminophen normally metabolized via glucuronidation but neonates and infants don’t have this ability so broken down by sulfate conjugation
22
Q
Elimination in babies?
A
- decreased plasma clearance of many drugs via the kidneys
- almost all drugs and metabolites are excreted through the kidneys
- GFR increases during first 2 weeks of life but doesn’t reach adult rates until 2
- immature renal system:
decreased tubular secretion and reabsorption rates, proximal tubule decreased ability to concentrate urine - abx with longer half lives in neonates due to decreased renal excretion - PCN, sulfonamides, ahminoglycosides
- thiazides: need GFR greater than 30 to be effective, neonates reqr higher doses or need to switch to stronger one (loop diuretic)
23
Q
Common overdoses in peds?
A
- Fe supplements: contained in some vitamins, counsel parents to dist vitamins from candy
- acetaminophen: deadly overdoses primarily in kids older than 12
- accidental or intended
24
Q
GI and IM absorption differences in peds to consider?
A
- infants and kids generally absorb meds more rapidly and completely than adults
- the younger the human, the more permeable the skin (creams - steroids watch out!)
25
What are drugs to avoid in peds?
- propylene glycol: added to many injectable drugs to increase stability
- may cause hyperosmolality in infants
- Benzyl alcohol (preservative in IV fluids): can cause metabolic acidosis, neuro damage in neonates
26
Liver and renal disease considerations in peds pharm?
- liver disease: data on dosage adjustments lacking in peds, monitor pt closely, avoid potentially hepatoxic drugs
- renal disease: data also lacking, monitor pt closely, avoid potentially nephrotoxic drugs
27
CF affect in ped therapy?
- increased requirements/increased clearance
- aminoglycosides
- PCNs
- theophylline
28
GI disorders considerations in ped therapy?
- dosage adjustments may be necessary:
celiac disease
gastroenteritis
severe malabsorption
29
A cc equals what?
- cc equal to ml
| - 5 cc = 1 tsp
30
Dosing of tylenol?
- 10-15 mg/kg q 4-6 hrs
- rectal acetaminophen is discouraged because its effects can vary widely
- wt based dosing preferred b/c it is more accurate
- comes in 7 oral dosing forms, and caregivers have problems dosing it properly
- most common problem is under dosing
31
Ibuprofen dosing?
- comes in 2 liquid strengths and 2 chewable tablets
- dose 5-10 mg/kg per dose every 6 hrs
- reserve 10 mg for high fevers
- motrin not labeled for infants less than 6 months
- infant drops: 50 mg/1.25 ml (40 mg/ml)
- liquid: 100/5 (20 mg/ml)
- motrin 50 mg and 100 mg chewables
- adult tabs: 200 mg each
32
When do you use adult dosing instead of ped dosing?
- when you have a larger kid
| - example: 40 kg kid dose him/her as adult otherwise giving too much
33
What 2 drug classes should you not use in peds pops?
- fluoroquinolones (tendon rupture) and tetracyclines ( teeth staining and bone growth)
Pediatrics
flashcards
Decks in class (20)
# Cards
-
Embryology23
-
Perinatal Period61
-
The newborn exam63
-
Well Child Care - Developmental assessment56
-
Congenital disorders95
-
Psych77
-
Oncology95
-
Common ped medical problems55
-
Ped pharm33
-
Childhood developmental behavior42
-
adolescent health26
-
Ortho55
-
Lung Diseases37
-
Immunizations37
-
Allergies51
-
ID I66
-
Child abuse and neglect32
-
Injuries and poisoning47
-
ID II72
-
Asthma Review32
