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Flashcards in Peds Pharm Deck (31)
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1
Q
What are the ages for the following terms:
Preterm/premature
Neonate
Infant
Child
Adolescent
A
Preterm/premature: less than 36 weeks gestational age
Neonate: Frist 30 days of life
Infant:1 month to 1 year
Child: 1-12 years
Adolescent:12-18 years
2
Q

Variables affect GI absorption how

  • pH
  • Gastric emptying time
  • Pancreatic enzyme activity
  • GI surface area
  • Intestinal microorganisms
A
  • pH
  • -more alkaline than adults until child reaches 1 year
  • -adversely affects the absorption of weakly acid drugs and improves the absorption of weakly basic drugs
  • gastric emptying time and GI motility
  • -slower than adults for the first month of life
  • -neonates and infants have irregular peristalsis
  • Pancreatic enzyme activity
  • -decreased in first year
  • -affects drugs that are fat soluble (neonates cant absorb vitamin E)
  • GI surface area
  • -In young children the relative size of the duodenum compared with the adults enhances drug absorption
  • Intestinal microorganisms
  • -Intestinal flora depends more on diet than age
  • -more rapid development of flora in breast fed infants
  • -flora is active in the breakdown of various drugs
3
Q

Rectal absorption

  • Used in who
  • drug is absorbed how
  • Problems with this method
A

Used in who
-those that cannot tolerate oral drugs or lack of IV access

drug is absorbed how
-by the hemorrhoidal veins and avoids first pass metabolism

Problems with this method

  • drugs are erratically and incompletely absorbed
  • babies dont have good sphincter tone so the meds could come right back out
4
Q

IM absorption

  • affected by
  • quality of absorption in neonates
  • quality of absorption in infants
A

Affected by
-muscle mass, blood flow to the muscle, tone, activity

Neonates
-Erratic and poor absorption d/t decreased muscle mass and activity and tone

Infants
-greater density of skeletal muscle capillaries than older children therefore more efficient absorption

5
Q

Percutaneous absorption

  • affected by
  • quality of absorption in neonates
A

Affected by:

  • thickness of the skin
  • body surface area relative to body mass

Neonates:
-have thin skin and increased body surface area relative to body mass, leading to significant drug absorption in neonates compared to adults

6
Q

Factors affecting distribution in pediatric patients (6)

A
  • vascular perfusion
  • body composition
  • tissue binding characteristics
  • physiochemical properties if the drug
  • plasma protein binding
  • route of administration
7
Q

Distribution: Vascular perfusion
-Are changes in perfusion common in neonates?
Ex

A

Changes in perfusion are common in neonates

Ex. in response to hypoxia, the blood mat be diverted (shunted) from the lungs to the tissues and organs. This could be a problem if we are trying to give an inhaled medication

8
Q

Distribution: Body composition

  • What happens to the volume of distribution if total body water and extracellular water increase?
  • Explain how this applies to neonates
A
  • The 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, so some drugs will require a larger dose per Kg in infants and younger compared to adults…think of it being more diluted (neonates are just little bags of water)
9
Q

Distribution: Tissue Binding Characteristics

-what happens to free blood levels of a drug when the mass of tissue is reduced?

A

Drugs bound to tissues exhibit increased free blood level when the mass of tissue is reduced such as in pediatrics

10
Q

Distribution: Physiochemical properties

-What properties affect the ability of the drug to move across membranes into target tissues and cells?

A
  • lipid solubility

- molecular configuration

11
Q

Distribution: Plasma protein binding

  • How is neonate protein levels different from adults?
  • what does this result in?
  • how does this affect neonate VD?
A

Neonates have:

  • decreased Alpha1-acid glycoprotein (binds alkaline drugs)
  • decreased albumin (bind drugs, fatty acids, and bilirubin)

This results in drug displacement and increased plasma levels due to decreased availability protein for binding

This means neonates have a larger volume of distribution compared to adults

12
Q

Distribution: Route of Administration
primary distribution site for:
-Orally
-IV

A

Orally

  • liver becomes the primary distribution site
  • affected by hepatic first pass metabolism

IV
-heart and lungs act as the primary method of distribtuion

13
Q

How is ECF different in neonates vs adults?

A

Neonates have about 40% of their body wieght as ECF while adults have about 20% of their body weight as ECF.

*Volume of distribution should reflect the ECF compartment of the patient
(volume of distribution-the more water there is, the more dilute the drug is going to be)

14
Q

What drugs have increased VD in neonates?

increased uptake and VD?

A

Increased VD in neonates

  • theophylline
  • ampicillin
  • phenobarbitol
  • phenytoin

Increased uptake and VD

  • morphine
  • fentanyl
  • digoxin
15
Q

Is drug metabolism delayed in neonates, infants, and young children?

What is drug clearance reliant on?

A

Yes!

Drug clearance is reliant on hepatic metabolism

16
Q

What are the phases of drug metabolism in neonates, infants, and young children?

A

Phase I (oxidation, reduction, hydrolysis)

  • CYP 450 system
  • decreased in neonates
  • need smaller doses and less frequent dosing)
  • increased in infants and children
Phase II (conjugation)
-acetaminophen normally is metabolized via gluconidation but neonates and infants dont have this ability so broken down by sulfate conjugation
17
Q

What is the half life of acetaminophen in neonates? Adults?

A

neonates: 3.5 hours

Adults: 2 hours

18
Q

What are the consequences of neonates and young children having an immature renal system?

A
  • decreased plasma clearance of many drugs via the kidneys
  • decreased tubular secretion and reabsorption rates
  • proximal tubules decreased ability to concentrate urine
19
Q

What antibiotics have longer half lives in neonates die to decreased renal excretion?

A
  • PCN
  • Sulfonamides
  • Aminoglycosides
20
Q

What are two common overdoses in young children?

A
  • Iron supplements (contained in some childrens vitamins)

- Acetaminophen

21
Q

Infants and children generally absorb medications more _____ and _____ than adults

A

Infants and children generally absorb medications more rapidly and completely than adults

22
Q

What are two drugs to avoid in pediatric patients?

A
  • 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, neurologic damage in neonates
23
Q

Cystic Fibrosis pts have increased requirements and increased clearance of what drugs?

A
  • aminoglycosides
  • PCN
  • theophylline
24
Q

What GI disorders may requires dose adjustments and why?

A
  • celiac disease
  • gasteroenteritis
  • severe malabsorption

-because these disease will affect the absorption of the drug

25
Q

___cc=___ml=___teaspoon

A

5cc=5ml=1 teaspoon

26
Q

Amoxicillin dosing example

  • 13kg pt
  • amoxicillin at 80-100mg/kg/day divided q12h/8h for 7-10 days
  • suspension 400mg/5ml
A

13kg x 80-100mg/kg/day=1040-1300mg/day

1040/2= 520mg
1300/2=650 mg

520/x=400/5…6.5 or 650/x=400/5…8.125

either choose 7 or 8mL

27
Q

What is the pediatric dose for tyenol?

Handy dosing?

A

Tylenol: 10-15mg/kg q4-6 hrs

24-36lbs=5ml
36-48lbs= 7.5ml
48-60lbs=10ml

28
Q

What is the pediatric dose for ibuprofen?

What age can you begin dosing this?

A

5-10mg/kg/dose q6-8 hours

Not labeled for infants less than 6 months, so 6 months!

29
Q

Once the pediatric dose reaches the adult dose, don’t go any further. True or false?

A

True, yo!

30
Q

Whats one of the most important things to remember about peds dosing?

A

That you can’t remember anything, so look it up! hehe

But really, everything changes, so look it up!

31
Q

What are two major drug classes to not used in the peds population?

A

Fluoroquinolones and Tetracyclines