paeds pharmacology

Question 1

why drug data can’t just be extrapolated from adults to children

Answer 1

• pharmacokinetic differences
• altered pharmacodynamic responses
• effects on growth and development not known
• different specific pathologies

Question 2

define off label medicines

Answer 2

licensed for human use but not for use in children below a certain age such as 16/18 years

Question 3

define unlicensed medicines

Answer 3

no license for human use in this country

Question 4

unlicensed/ off-label prescribing

Answer 4

formulation administered via a route not intended

used for an indication not intended

used at a difference dose to recommended

children below stated recommended age

used without a license, including those being used in clinical trials

Question 5

main reason neonates/ infants are more sensitive to drugs than adults

Answer 5

organ system immaturity

Question 6

describe physiology of child during early post natal period

Answer 6

• rapid growth
• highly variable alterations in drug metabolism and elimination
• low ADR tolerance
• difficult identifying efficacy and toxicity

Question 7

describe physiology of infancy

Answer 7

body weight gain and body water composition change rapidly, as does the ratio of bodyweight or surface area to organ size and function

Question 8

describe physiology of a toddler

Answer 8

• associated with lots of minor illnesses

- problems with compliance

Question 9

describe physiology young child

Answer 9

• enhanced metabolism and excretion

- clearance can change significantly during a single dose regimen

Question 10

describe physiology adolescence

Answer 10

• sexual development has major affects on body size and compositon
• psychological changes and peer pressure result in behaviours such as smoking, alcohol, and elicit drug use which can alter drug metabolism

Question 11

examples of drugs with narrow therapeutic index

Answer 11

• digoxin
• SSRI
• anti epileptics
• cytotoxics

Question 12

when are adult gastric acid and gastric emptying levels reached?

Answer 12

3 years

Question 13

when are adult absorption values reached in children

Answer 13

6-8 months

Question 14

benefits of rectal administration of medications in children

Answer 14

• vomitting
• unwilling to take oral meds
• avoids first pass metabolism

Question 15

describe newborns extracellular fluid volume compared with an adults

Answer 15

around 45% compared to adults 20-25%. drops to 25% @ 1year

Question 16

total body water composition compared with adults

Answer 16

75-92% compared with 50-60%

Question 17

fat content term infants compared with adults

Answer 17

12% term infants

18% adults

Question 18

fat content 1 year compared with adults

Answer 18

30% 1 year

18% adults

Question 19

describe plasma protein bonding in neonate and effect

Answer 19

reduced

results in greater unbound or active drug

Question 20

describe blood-brain barrier in neonates

Answer 20

• not fully developed @ birth
• drugs and other chemicals have relatively easy access to CNS
• infants especially sensitive to drugs that affects CNS function, causing CNS toxicity

Question 21

describe drug elimination in children

Answer 21

takes longer due to immature hepatic metabolism and renal elimination

Question 22

describe hepatic metabolism in children

Answer 22

• very slow in neonatal period
• neonates especially sensitive to drugs eliminated by hepatic metabolism
• @ adult rates by 1 year

Question 23

describe hepatic metabolism in older children

Answer 23

can be greater than in adults, with shorter hand life. this can result in greater doses needed for drugs such as anti-epileptics than in adults

Question 24

when are adult values for renal excretion achieved in children

Answer 24

3-6 months

Question 25

what metabolic disturbances increase sensitivity to drugs

Answer 25

• fever
• dehydration
• acidosis

Question 26

what resource can be used for parents and patients to report suspected side effects

Answer 26

• yellow card — online/ leaflet/ calling them