Pharmacology Flashcards
Can breast fed infants be affected by their mothers medication?
Yes
Neonates/infants response to drugs compared to adults
More sensitive
What do neonates/infants show increased risk for?
Adverse drug reactions
The young child has enhanced what?
Metabolism
Excretion
What produces major changes in body size and composition in adolescence?
Sexual development
What can alter drug metabolism in adolescence?
Psychological changes and peer pressure resulting in behaviour e.g. smoking, alcohol and elicit drug use
What SSRI is used in childhood depression?
Paroxetine
How can drugs be administered in children?
Oral
Parenteral
Topically
Rectally
Differences in children with oral medicines
Reduced gastric acid and delayed gastric emptying. adult levels reached at 3 years
Absorption reaches adult values by 6-8 months
A lot of variability
Who gets rectal medication?
Vomiting
Unwilling to take oral medication
What does rectal medication avoid?
First pass metabolism
Drug Distribution in infants
Newborn infants high extracellular fluid of 45%
Total body water is high 75-92%
Fat content low 12% in term infants
Drug doses in children
Larger initial doses on a mg/kg body weight needs to be given to achieve a correct plasma concentration
Plasma protein binding in neonates
Reduced in neonates
Results in a great unbound or active drug
Drug elimination in neonates
Neonate liver metabolism is immature and thus drugs eliminated by the liver have a longer half life
Hepatic metabolism in the neonatal period
Very slow
Oxidation and glucuonidation
Especially sensitive to drugs eliminated by hepatic metabolism
Metabolic activity increases rapidly from about 1 month after birth with adult activity by 1 year of age
Drug changes in older children
Because of hepatic metabolism the dose-age of some drugs e.g. anti epileptics would be greater
Renal excretion in neonates
Decreased in neonates
Shows progressive maturation with age
Adult values achieved at 3-6 months
For most drugs t1/2 is prolonged
Pharmokinetics of new borns and babies in first year of life compared to adults
decreased Albumin proteins mean free drug increases
Increased free drug levels leads to increased response
Decreased hepatic metabolism leads to increased response
Decreased renal elimination leads to increased response
Decreased BBB leads to increased CNS effects
Sensitivity to drugs is increased by…
Fever
Dehydration (increased effects of many drugs)
Acidosis (decreased cellular penetration of basic drugs)
