paediatric pharmacology Flashcards
safe + effective use of medicines in children is complicated by
lack of acute dosage data
lack of approp formulations allowing accurate dosage and delivery
difficulty detecting ADRs
key prescribing points
- use most simple dosage regime
- pay attention to formulation, route and duration of therapy
- involve parents in prescribing choice
- check with BNFc
why cant extrapolate doses for kids based on adult dose data
- pharmacokinetic differences between adult and children
- altered pharmacodynamic response
- effects on growth and development not known
- different specific pathologies
off-label medicines
licensed for human use but not for use in children under certain age (16 or 18) or not via a certain route or not for a certain disease treatment
unlicensed medicines
no licence for human use in UK
-includes licensed medicines which are reformulated for easy use in children
what are the reasons for off-label prescribing
- formulation administered via route not intended
- medicines used for an indication not intended
- medicine used at different dose than recommended
- kid under recommended age
- medicines without licence: incl those made esp for child/used in clinical trials
why are neonates/infants more sensitive to drugs than adults
mainly due to organ system immaturity
what are neonates/infants more at risk of
adverse drug reactions
what do younger patients show
greater individual variation
neonate age
0-27 days
infant age
28days - 23mo
child age
2yrs - 11yrs
adolescent age
12yrs - 16/18yrs
neonate: phase of physiological immaturity with
- rapid growth
- highly variable alterations in drug metabolism and elimination
- lower tolerance to ARDs
- difficulty in identifying efficacy and toxicity
infancy pharmacology
body weight gain and body water composition change rapidly
as foes ratio of bod weight/surface area to organ size and function
toddler pharmacology
minor illnesses leading to multiple short courses of therapy
problems with compliance
young child pharmacology
enhanced metabolism and excretion
clearance can change significantly during a single dose regimen
adolescent pharmacology
sexual development produces major changes which affect drug metabolism
psychological changes and peer pressures results in smoking, alcohol, elicit drug use which alter drug metabolism
oral route of administration
- reduced gastric acid + delayed gastric emptying
- absorption via GIT reaches adult by 6-8mo
- bioavailability of drugs reduced + highly variable
- drugs which rely on entero-hepatic circulation highly variable e.g. cyclosporin
percutaneous route of administration
enhanced in infants and children, esp w damaged skin or an occlusive dressing
steroids
rectal route of administration
used in pts who are vomiting/unwilling to take oral meds
avoid 1st pass metabolism
IV route of administration
delayed or uncertain delivery
