Considerations in Pregnancy + drug use in pregnancy and lactation Flashcards
what CV characteristics are increased in pregnancy?
blood volume
cardiac output by 8wks
what are some possible causes to increased lower limb venous pressure with pregnancy
enlarging uterus impedes inferior vena cava pressure + placenta acts as AV shunt
3rd trimester may see ___________ episodes from gravid uterus impeding flow in ____________
supine hypotensive
inferior vena cava
what CV characteristics are decreased in pregnancy?
BP in first trimester
systemic peripheral vascular resistance
what respiratory characteristics are increased in pregnancy?
oxygen consumption
sensitivity of medullary respiratory center to CO2
minute ventilation (tidal volume and resp rate)
what resp characteristics are decreased in pregnancy?
residual volume
in pregnancy, there may be compensatory respiratory ________
1. acidosis
2. alkalosis
alkalosis
why does the medullary respiratory center become more sensitive to CO2 in pregnancy?
effects of progesterone
how much iron supplementation is recommended during last half of pregnancy?
50-60mg
absorption of iron
1. increases
2. decreases
in pregnancy
increases by 15%
pregnancy sees an increase in clotting factors due to
increased estrogen
why is there an increased risk of thrombosis peripartum
Virchow’s triad: venous stasis (rest), hypercoagulability (E), endothelial damage (from delivery)
in pregnancy, the smooth muscle of the GIT ____________, resulting in _____________
1. relaxes, faster gastric emptying
2. relaxes, slower gastric emptying
3. increases tone, faster gastric emptying
4. increases tone, slower gastric emptying
2
delayed gastric emptying in pregnancy results in
upper GI sx like heartburn/ GERD
N/V
what are some renal adaptations seen in pregnancy
increased blood flow and GFR
increased activity of the RASS system (from E)
increased glucosuria
in pregnancy, is glucosuria present in nondiabetics?
yes- GFR increases but ability to absorb glucose remains teh same
may not be a good indicator of glucose control in diabetics
a T1DM pregnant patient is having glucosuria, this
1. indicates a loss of blood glucose control
2. indicates diabetic ketoacidosis
3. may be present at normal blood glucose levels
4. is a good indicator of diabetes in pregnancy
3
PK changes in pregnancy includes
increased Vd adn CL
decreased GI motility = slower absorption time = later peak
decreased protein binding (albumin)
Maternal and fetal drug response during pregnancy are influenced by 2 factors
Pregnancy induced physiologic changes
Placental fetal unit
rank the following teratogens on incidence of congenital manifestations
unknown, genetic, medication exposure, environment
unknown > genetic > environment > med exposure
list 3 factors that can influence teratogenicity
The embryonic stage at exposure
Genotypes of the mother a fetus
The extent to which the drug crosses the placenta
Type of agent: dose, duration of exposure
Simultaneous exposure to other drugs/ environmental agents
placental drug transfer can occur by
simple diffusion, differential diffusion, active transport, and pinocytosis
placental drug transfer is influenced by
MW, protein binding, lipid solubility, degree of ionization, placental blood flow, placental metabolism, thickness of placental membrane
list 3 reasons why it is difficult to determine the safety of drugs in pregnancy
most RCTs exclude pregnant women
oevrall risk of most teratogens is low = needs large number of exposures
most data currently from case reports that is not generalizable to all women
small sample sizes
contribution of maternal disease unknown
recall bias in retrospective studies
unbalanced reporting
what are pregnancy registrise
post marketing data, voluntary, recorded prospectively
what meds mother was taking, if there are any effects on baby
what 4 drugs can affect brain development
isotretinoin, phenytoin, carbamazepine, valproic acid
lsit the 9 proven teratogens
thalidomide
DES
alcohol
cocaine
androgens
isotretinoin
warfarin
methotrexate
valproic acid
Alcohol use during pregnancy is associated with a range of complications called
FASD
FASD
1. results in lifelong physical, behavioural, intellectual effects
2. is completely preventable by avoiding alcohol in pregnancy
3. severity depends on amount of alcohol drank, timing of drinking
4. all of the above
4
when is the fetus most vulnerable to alcohol
days 19-21
what is the most severe subtype of FASD
FAS- physical + brain damage + neurodevelopmental effects
what % of FAS have the classical characteristics
10%
what are some classical sx of FAS
low nose bridge, short nose/ flat midface, smooth philtrum, thin upper lip, small jaw, microcephaly, epicanthal folds, short palpebral fissures, minor ear abnormalities, height/ weight <10th percentile
neurodevelopmental effects, no physical evidence
ARND
many birth defects (ex- cardiac, skeletal, renal, etc) from alcohol
ARBD (alcohol related birth defects)
what is pFAS
(partial fetal alcohol syndrome): partial physical effects and neurodevelopmental effects
neonatal adaptation sx usually resolves in
~2wks
common drugs precipitating neonatal withdrawal includes
drugs of abuse, psychotropic drugs, antidepressants (SSRIs)
Some drugs can cause withdrawal sx in the neonate (if taken during the ________________)
last trimester around the time of delivery
cannabis in pregnancy may affect ________, ____________, ___________ consequences
May affect fetal growth (inconsistent evidence), neurodevelopment, learning and behavioral consequences
evidence of cannabis in pregnancy mostly comes from
1. smoking
2. edibles
3. sprays
1
general guidelines for ITC use with pregnancy (4)
Try nonpharm first
Try to avoid meds during first trimester
Use noncombination, short acting agents
Choose topical over oral meds
passage of medication into milk is primarily from
passive diffusion
drug transfers into human milk more easily if it is
Highly lipid soluble
Low in protein binding
Low in MW (<500d)
Nonionized (pKa important)
High conc in mother
general rules for taking meds in breastfeeding
Choose drug with less secretion into milk
Avoid nursing at times of peak drug conc
Take med before infant’s longest sleep period
If ST tx, consider temp holding BF
medication levels tend to peak in breastmilk ____ after oral dose
1-3hrs
Relative infant dose
Relative infant dose = infant’s dose via milk (mg/kg/d)/ mother’s dose (mg/kg/d)
what is L1 in Hale’s medication
safest
if the RID is < ____, it is generally safe to use
10%
RID of most meds are ___
<1%
what % of THC exposed to the mother reaches the baby?
0.8-2.5%
