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Flashcards in Pharmacology Deck (40)
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1

Variables Affecting GI Absorption

pH
Gastric emptying time
GI motility
Pancreatic enzyme activity
GI surface area
Intestinal microorganisms

2

pH and GI Absorption

More alkaline than adults
Decrease absorption of weakly acidic drugs
Increase absorption of weakly basic drugs

3

Gastric Emptying Time/GI Motility and GI Absorption

Slower than adults
Irregular peristalsis

4

Pancreatic Enzyme Activity and GI Absorption

Decreased for first year of life
Affects drugs that are fat soluble

5

GI Surface Area and GI Absorption

Intestinal size vs. body size
Enhances drug absorption

6

GI Microorganisms and GI Absorption

Intestinal flora depends on diet
More rapid development of flora in breast fed infants
Flora active in breakdown of drugs

7

Rectal Absorption and GI Absorption

Cannot tolerate oral drugs/lack IV access
Absorbed by hemorrhoidal veins
Erratically & incompletely absorbed

8

IM Absorption Affected by:

Muscle mass
Blood flow to muscle
Tone
Activity

9

IM Absorption in Neonates

Decreased muscle mass
Decreased blood flow
Erractic/poor drug absorption

10

IM Absorption in Infants

Greater density of skeletal muscle capillaries
Efficient absorption

11

Percutaneous Absorption Affected by:

Thickness of skin
Body surface area to body mass

12

Thin Skin + Increased Body Surface Area =

Significant percutaneous drug absorption
Watch for toxicity

13

Factors Affecting Distribution in Pediatric Patients

Vascular perfusion
Body composition
Tissue binding characteristics
Physiochemical properties of the drug
Plasma protein binding
Route of administration

14

Vascular Perfusion in Distribution

Changes in perfusion common

15

Body Composition in Distribution

Higher body water & ECF the larger the volume of distribution
Some drugs need larger doses/kg

16

Tissue Binding Characteristics in Distribution

Drugs bound to tissues exhibit increased free blood levels when the mass of tissues i reduced

17

Physiochemical Properties in Distribution

Lipid solubility
Molecular configuration

18

Plasma Protein Binding in Distribution

Decreased alpha1-acid glycoprotein
Decreased albumin
Increased plasma levels of drugs
Larger volume of distribution in neonates

19

Routes of Administration

Orally
IV
IM

20

Oral Route of Administration

Liver primary distribution site
Hepatic first pass metabolism
Oral doses higher than IV doses

21

IV Route of Administration

Heart and lungs primary method of distribution

22

Increased Volume of Distribution of Protein Binding Drugs

Theophylline
Ampicillin
Phenobarbital
Phenytoin

23

Increased Uptake and Volume of Distribution of Tissue Uptake

Morphine
Fentanyl
Digoxin

24

What is delayed in neonates, infants, and young children?

Drug metabolism
Plasma clearance of drugs

25

GFR of Neonates Compared to Adults

Decreased until age 2

26

Decreased GFR Leads to:

Decreased tubular secretion & reabsorption rates
Proximal tubule decreased ability to concentrate urine

27

What are some common overdoses in children?

Iron supplements
Acetaminophen

28

GI and IM Absorption in Pediatric Patients

Infants & children absorb medications more rapidly & completely
Younger the human, more permeable the skin
Readily eliminate meds that are cleared renally

29

Drugs to Avoid in Pediatric Patients

Propylene glycol
Benzyl alcohol

30

Factors Affecting Pediatric Therapy

Liver disease
Renal disease
Cystic Fibrosis
GI disorders