Peds Pharmacology Flashcards
less than what % of drugs used on neonates are FDA approved?
5%
what are the only 3 drugs approved for use on neonates? (R,R,S)
- remifentanil
- rocuronium
- sevoflurane
body composition:
- does total body water increase or decrease with age?
- does fat increase or decrease with age?
- does muscle increase or decrease with age?
- decrease
- increase
- increase
what is it called when the amount of drug removed from the body equals the amount of the dose?
steady state
body water composition:
- do infants have most of their total body water intracellular or extracellular?
- because of their body water composition, what puts infants at risk for dehydration?
- extracellular
2. unable to mobilize water from cells because don’t have much water in there
what 3 things make up total drug effect? (TBW, ME, PB)
- total body water
- maturational effects
- protein binding
protein binding:
- does protein binding increase or decrease with age?
- does the amount of free drug increase or decrease with age?
- increase
2. decrease
protein binding:
- does albumin concentration increase or decrease with age?
- do acidic or basic drugs bind to albumin?
- does alpha-1 acid glycoprotein increase or decrease with age?
- at birth alpha-1 acid glycoprotein is what % amount of adults?
- do acidic or basic drugs bind to alpha-1 acid glycoprotein?
- increase
- acidic
- increase
- 50%
- basic
what type of meds are an example of a basic drug?
amide local anesthetics
what 1 drug and 1 drug type are acidic? (D, B)
- diazepam
2. barbiturates
does the liver make meds more or less polar?
more polar
half-life is confounded by what 2 things? (C, V)
- clearance
2. volume
half-lives of meds:
- in one word, describe them in neonates? (P)
- do they increase or decrease in children 4-10 years old?
- at what age period do they reach adult values? (A)
- prolonged
- decrease
- adolescents
do half-lives increase or decrease with age?
decrease
biotransformation/metabolism are affected by what 3 things? (E, IE, M)
- enzyme
- induction exposure
- medications
Phase 1 reactions:
- what are 3 reactions in phase 1? (H, O, R)
- what group of enzymes provides the majority of phase 1 drug metabolism?
- in this phase, a parent drugs is converted into a more polar active metabolite by inserting a what on it? (PFG)
- hydrolysis, oxidation, reduction
- cytochrome P-450
- polar functional group
phase 2 reactions:
- what are 3 reactions in phase 2? (G, A, S)
- in this phase, a parent drug is converted to a more polar inactive metabolite by conjugation of what to functional groups? (S)
- used to facilitate elimination via what organ?
- what are 3 enzymes in this phase? (UD, S, NA)
- glucuronidation, acetylation, sulfation reactions
- subgroups
- kidney
- uridine diphosphoglucuronosyltransferase, sulfotransferase, N-acetyltransferase 2
fetal hepatic metabolism:
- starts as early as what range of weeks gestation?
- liver enzyme activity is what % range of an adult?
- 9-22 weeks gestation
2. 2-36%
neonate hepatic metabolism:
- is metabolism overall increased or decreased in neonates?
- as hepatic blood flow increases as the infant matures, does metabolism increase or decrease?
- does an open or closed PDA effect drug delivery to metabolizing organs?
- decrease
- increase
- yes
CYP-450:
- these enzymes are increase or decreased in neonates, which increases or decreases clearance and increases or decreases half-lives of meds?
- what CYP-450 enzyme is the most important because it has the broadest range of drgs it metabolizes and compromises the majority of the enzymes in the adult liver?
- this enzyme approaches adult levels by what post-natal month range?
- decreased, decreases, increases
- CYP3A
- 6-12 months
what 7 meds are metabolized by phase 1? (A,C,C,L,M,N,O)
- acetaminophen
- caffeine
- codeine
- lidocaine
- midazolam
- nicotine
- omeprazole
what 4 meds are metabolized by phase 2? (A,C,L,M)
- acetaminophen
- caffeine
- lorazepam
- morphine
what 3 things combine to decrease renal excretion in peds? (IGD, LPP, IOL)
- incomplete glomerular development
- lower perfusion pressure
- inadequate osmotic load
renal excretion:
- normal renal clearance by what months?
- fully mature by what age in years?
- 4 months
2. 2 years
renal drugs:
- what 2 abx have an increased half-life in peds because they are primarily excreted by the kidneys? (A, C)
- what LA can build up in peds and cause seizures d/t decrease renal excretion?
- aminoglycosides, cephalosporin
2. bupivacaine
pharmacokinetics are referred to the changes in what within what over time?
changes in drug concentrations within the body
first order kinetics:
- constant what is removed per time?
- is more drug removed at a higher concentration?
- fraction
2. yes
does a portion of enzymes needs to be free in order for first order kinetics to work?
yes
zero order kinetics:
- constant what is removed per time?
- why is it also referred to as saturation kinetics?
- what 3 drugs are eliminated by these kinetics at therapeutic doses in neonates? (C,D,F)
- amount
- because this type of kinetics occurs when the enzymes are saturated
- caffeine, diazepam, furosemide
what is context-sensitive half-life?
the amount of time required for the plasma drug concentration to decrease by 50% after infusion termination
half-life:
- how many half lives does it take to reach steady state equilibrium?
- when are loading doses used?
- 5
2. when the time to reach a constant concentration is excessive (3-5 half-lives)
Body composition:
- do infants have a greater Vd for fat-soluble or water-soluble meds?
- because of this, do they need an increased or decreased loading dose based on body weight to get target concentrations?
- do term neonates need a greater or lesser loading dose for some meds than older children?
- do neonates tend to be sensitive to the respiratory, neuro, and circulatory effects of many meds, and therefore more responsive to effects at a reduced blood concentration compared to children and adults?
- water-soluble
- increased
- greater
- yes