Special Population Considerations Flashcards
over the last several decades, 1st trimester use of perscription medications increased over ___%
60%
in general, medications should be ____ during pregnancy
avoided
when to use medication during pregnancy (1)
when necessary
what percent of birth defects may be a result of a medication
2-3%
pregnant women are what is considered a ____ _____ in medicine
vulnerable population
most medications are not ____ for pregnancy
tested
the placental barrier is a ______ membrane
semi-permeable
the placental barrier (2)
- site of metabolism for some drugs
- has protective effect on fetus
drugs that have crossed the placenta enter the fetal umbilical cord via the _____
umbilical vein
40-60% umbilical venous flow goes to ___ ____
fetal liver
by entering the fetal liver prior, this allows for _____ ______ before entering fetal circulation
partial metabolism
factors affecting placental drug transfer (5)
- stage of placental/fetal development
- physiochemical properties of drug
- rate at which drug crosses placenta
- duration of exposure to drug
- distribution characteristics
what type of drugs tend to readily diffuse across the placenta and enter fetal circulation?
lipophilic
drug passage is dependent on (2)
- lipid solubility
- degree of ionization
drugs of what size easily cross the placenta
250-500MW
drugs of what size cross the placenta with difficulty
500-1000
drugs of what size are restricted from crossing the placecnta
> 1000
certain transporters pump drugs back into maternal circulation and others are upregulated
drug transporters
what might affect the rate of transfer and amount transferred
protein binding
in some cases, like when using corticosteriods to simtulate fetal lung matuation the (fetus/mom) is the target of drug therapy
fetus
corticosteroids stimulate
fetal lung maturation in expected preterm birth
by using corticosteroids it reduces the occurence of ____ _____ _____ _____
infant respiratory distress syndrome
what is the period of optimal benefit for corticosteroids in preterm fetus’
24 hrs after dose, up to 7 days
other benefits of corticosteroids in fetus (3)
- decrease risk of inter-ventricular hemorrhage (brain bleed)
- decrease risk of systemic infections
- lower neonatal mortality rate
what is the most important factor in premature fetus?
lung maturation
antenatal steroids are
before birth
what do antenatal steroids work on?
type II pneumocytes in alveoli of the lungs
what does antenatal steroids do (2)
- increase maturation
- increase production of surfactant
chronic maternal opioid use can lead to
dependence in the fetus (neonatal abstinence syndrome)
associated risks of opioid use during pregnancy (7)
- preeclampsia
- increased risk of defects
- increased risk placental abruption
- problems with fetal growth
- miscarriage / stillbirth
- sudden infant death syndrome
- maternal cardiac arrest
teratogenicity allows you to (2)
- exert effects at certain stage of fetal development
- show dose-dependent incidence
substance or process resulting in characteristic set of malformations
teratogenic
teratogenic mechanisms negative outcomes(4)
- direct effect on maternal tissues
- interference with oxygen/nutrients passage through placenta & rapidly metabolizing
- direct actions on processes of differentiation in developing tissues
- deficiency of a critical substance (enzyme inhibition)
a shit ton of development occurs in the fetus from ____ weeks
1-8ish
gestation is divided into four stages, name then
- blastocyst
- organogenesis
- histogenesis and maturation
- labor and delivery
days/weeks for gestation
1. blastocyst
2. organogensis
3. histogenesis and maturation
4. labor and delivery
- 0-16 days
- 17-60 days
- 2nd and 3rd triemester
- birth (duh)
blastocyst (days, what occurs if exposed to teratogen)
0-16
teratogen exposure may result in pregnancy termination
ALL or NONE phenomena
organogenesis (days, what occurs if exposed to teratogen)
17-60 days
teratogen exposure during stage can cause gross structural malformation
histogenesis (what occurs, what happens if teratogen exposure occurs)
ongoing growth and fetal development
teratogen exposure = effects on growth and development
examples of effects of teratogen exposure during histogenesis and maturation (3)
pre-term labor and delivery, IUGR, low birth weight
effects of teratogen exposure during labor and delivery stage
behavioral changes
Pitocin/fentanyl associated with decreased _____ in ____ ____ _____
suckling in skin to skin contact
what was thalidomide perscribed for?
sleep aid and for nausea and vomiting, used for morning sickness in pregnant women
when did thalidomide become OTC in Germany?
1957
why did they approve thalidomide?
it worked in rats lol
what was the adverse effect of thalidomide
phocomelia
when was the first case of phocomelia reported?
1961
what is phocomelia?
congenital absence or underdevelopment of extremities. affecyed >10,000 children, ~50% survived
what is thalidomide used for now?
first line for multiple myeloma
when was the USFDA drug classification system established?
1979
how many categories in the FDA classification system?
5, ABCDX
Classification of:
A
B
C
D
X
A: no risk on human studies
B: no evidence of risk on animal studies
C: risk cannot be ruled out, concerning animal data
D:positive evidence of human fetal risk, can be justified in certain circumstances
X: contraindicated in pregnancy
the pregnancy letter category system is overly _____
simplistic
how did they fix the pregnancy grading system?
pregnancy and lactation labeling (PLLR)
PLLR assisted healthcare providers in what way?
- assess benefit vs risk
- changing content/format of information of drug labeling
updated labeling categories (3)
- Pregnancy
- Lactation
- Females and Males of Reproductive potential
meds pass through the breast milk via _____ _____
passive diffusion
factors affecting distribution of breastfeeding/lactation and drug therapy
- breast milk is more acidic than plasma
- weakly acidic drugs less likely to pass through membrane
- meds that are high protein bound, low lipid solubility, or large molecular weight do not enter breastmilk
drugs that are prescribed directly to ____ are usually safe
infants
doses transferred via breastmilk are ____ than therapeutic doses
much lower
breastfed infants are generally not affected by medications with poor _____ bioavailability
oral (like insulin or heparin)
to avoid interactions while breastfeeding, breastfeeding _____ to medication administration is good
PRIOR
the greatest exposure to drug therapy during breastfeeding occurs within the ____ _____ ____ after med admin
first few hours
drugs with longer half lives are more likely to maintain _____ levels in breastmilk
higher
how much of the medication dose transfers to infant while breastfeeding?
1-2%
what medications decrease breast milk volume
- dopamine agonists (bromocriptine)
- decongestants (Zyrtec, Claritin, Allegra)
- estrogens (contraceptives)
bromocriptine is assosiated with maternal
death (from MI)
what is lactmed
online website to see how medicines interact with infant through breastmilk
what is the definition of a premature neonate (age)
<37 weeks
full term neonate
37-42 weeks
postnatal age
< 28 days
infant age
28-1 year
pediatric child age
1-12 years
pediatric adolescent age
13-17 years
pediatric absorption factors to think about (3)
- blood flow at site of admin
- Skin thickness/hydration
- Gastric acid production
blood flow at site of administration
- reduced muscle mass
- diminished peripheral perfusion
(can result in erratic absorption)
skin thickness and hydration
enhanced absorption with topical products
gastric acid production
reduced in infants, increased pH in stomach (more basic)
when do infants achieve adult gastric acid values
3 years
when do preterm infants produce gastric acid
32 weeks
what type of absorption is affected by gastric acid production
oral
distribution factors in neonate (3)
- higher percent of body weight in form of water
- extracellular water is increased
- total body fat is greater in full term vs preterm
water soluble drugs will have an _____ volume of distribution in neonates
increased
adjust dose based on patients
weight
in lipophilic drugs adipose tissue acts as a _____ _____
drug reservoir
if a preterm infant has a lower body fat there will be
increased risk for high serum concentration
is protein binding increased or decreased in neonates and infants?
reduced
a decreased amount of bound drug in infants and neonates means that there will be an _____ amount of free drug
increased
drugs given to neonates with jaundice displaces ______ from _______
bilirubin from albumin
bilirubin entering the brain =
kernicterus
is the liver mature at infant birth?
no
why do we have a dosage schedule for children, aka not dosing children like “mini adults”
their livers are not fully developed - that would be bad
if we dosed children like mini adults what would happen?
increased risk of drug toxicity
what other major organ is immature at birth?
kidney
how is the kidney immature at birth?
anatomically, functionally, nephrogenesis occurs til 35 weeks gestation
Glomerular filtration rate in newborns important to knows (4)
- much lower in newborns than infants/children
- even lower in neonates before 34 wks gestation
- functional improves within 1st week of life
- drug dependent on renal function cleared SLOW in first weeks of life
how does pediatric dosing work?
mg/kg or mg/m2
when calculating a pediatric dose you DO NOT
exceed adult doses
is there a standard dose for kids?
NO, calculated by body or surface area
what are the types of pediatric oral liquids?
- Elixers
- suspension
difference between an elixir and a suspension
elixer contains alcohol to help dissolve better. Suspension has undissolved particles… you gotta shake!!
common volumes for oral liquids in pediatric doses
teaspoon = 5 mL
tablespoon = 15 mL
what are 4 compliance considerations to tell parents when giving a child an oral medication
- use calibrated medication syringe - not a spoon lol
- choose a convenient dose forms and make a schedule
- educate when to re dose
- make sure they FINISH the antibiotic (if thats what theyre taking)
does the functional capacity of organ systems decline as get older? if so what age do you think it starts?
yes, 45
geriatric patients do not LOSE functions at an accelerated rate they ACCUMULATE more _______
deficiencies
absorption in geratric patients is altered due to (3 things)
- altered nutrition habits
- increased consumption of OTC meds
- slower gastric emptying
the altered absorption factors in geriatric patients are altered mainly due to
increased gastric pH
distribution of medication in geriatric patients affected due to (a million things, name a few lol)
- decreased lean body mass
- decreased total and percentage body water
- increased percent body fat
- reduced concentration of serum albumin
- decreased blood flow
- decreased liver function –> 7. decreased metabolism
metabolism of meds in geriatric patients is affected by
- capacity of liver does not consistently decline with age for all drugs
- greatest change in PHASE 1 REACTIONS - conjugation less affected
- decreased blood flow to liver and regeneration
excretion of meds in geriatric patients is affected by
- age-related decline in renal function
- prolongation of half-life in drugs = accumulation
are elderly at risk to experience an adverse drug reaction, if so why?
yes, they take a shit ton of drugs and dont know what half of them do, mix and match is fun in pill form!
what are some potential explanations to adverse drug reactions? (other than fun pill mix and match)
- poly-pharmacy
- error in prescription
- error in drug use (noncompliance, cost, forgetfulness, etc)
- OTC meds
prescribing cascade =
when you get a side effect to a med, and you fix it with a new med. then your new med causes a side effect so you get a med for the med that you were using to fix the side effect of the first med. works sometimes - not often lol there are better ways to avoid this problem.
tips for managing polypharmacy (5)
- keep an accurate updated list
- inform doc of any supplements you start
- understand why you take the medication
- simplify meds, discontinue ones you don’t need
- take ALL AS PRESCRIBED
promoting adherence in drug therapy in geriatric patients
- clearly label, easy open containers
- daily reminders
- ensure a support system is in place
- frequently monitor patients
