Pharm Antenatal and Perinatal - Wolff Flashcards
- misoprostol
- dinoprostone
- carboprost
- oxytocin
- ergot alkaloids
labor induction/control post-partum hemorrhage
- cortisol
- betamethasone
- dexamethasone
corticosteroids
- terbutaline
- indomethacin
- nifedipine
- MgSO4
- atosiban
tocolytics (delay labor)
what drugs are used to keep the ductus arteriosus open?
alprostadil, misoprostol
what drugs are used to close a PDA?
indomethacin, ibuprofen
- a-methyldopa
- labetalol
- hydralazine
- Na-nitroprusside
anti-hypertensives in pregnancy
what are the key factors thought to regulate phase 1 of parturition (labor)?
nitric oxide, hCG, progesterone
what are the key factors thought to regulate phase 2 of labor?
gap junction receptors, prostaglandins, hyaluronan
what are the key factors thought to regulate phase 3 of labor?
oxytocin, estrogen
what are the key factors thought to regulate phase 4 of labor?
inflammatory cell activation
process in which collagen and glycosaminoglycans are broken down in the cervix by matrix metallo-proteinases
- cervix becomes thin (effacement) and dilates
cervical ripening
synthetic prostaglandin E1 analog
- induces uterine contractions
- used to terminate intrauterine pregnancy if <70 days (in combination with mifepristone)
- off-label cervical ripening
- stable at room temp, cheap!
misoprostol
- causes NVD, can cause hypoxia in fetus
what are the contraindications of misoprostol?
pregnancy (unless aborting)
previous c-section (disrupts uterine scar -> rupture!)
synthetic prostaglandin E2 analog
- induces uterine contractions AND promotes cervical ripening
- available as gel, vaginal insert, or suppositories
- much more expensive than miso, needs to be refrigerated
dinoprostone
- causes NVD, fever (not responsive to NSAIDs)
- can cause hypoxia in fetus d/t tachysystole
synthetic prostaglandin F2a analog
- induces uterine contractions
- used to induce abortion b/w 13-20wks (if other methods don’t work)
- also used for post-partum hemostasis for refractory bleeding
- given IV, is expensive
carboprost
- causes HTN and pulmonary edema, is a potent vasoconstrictor (unlike PGE2)
- tends to reduce body temp (unlike PGE2)
- dizziness, gagging, heartburn, cough… lots of other side effects
posterior pituitary hormone
- increases force, frequency, and duration of uterine contractions (both induction and augmentation, but should be used with caution)
- administered IV, is cheap
oxytocin
- can cause water intoxication (rare) because structure is similar to ADH
NOTE: only works in uterus AT TERM (cervix needs to be ripe before uterus contract, otherwise it can rupture)
stimulates adrenergic, dopaminergic and serotogenic receptors
- causes prolonged tonic uterine contractions (not good for fetus)
- constricts arterioles and veins
- used POST-PARTUM to increase uterine tone and stop bleeding
- oral, IV or IM admin
ergot alkaloids (constrictor from rye fungus)
what are the contrindications of ergot alkaloids?
HTN, hypersensitivity
- very rarely can cause psychosis or convulsions (the whole witchcraft thing)
what drug class works well for cervical ripening, and can cause uterine contractions at any time during pregnancy (used for abortions)?
PGE analogs (prostaglandins)
what drug is used during labor and delivery to help induce AND augment contractions
- also helps limit post-partum bleeding
oxytocin
what is the second choice for limiting post-partum bleeding?
ergot alkaloids
what is the best tx for preeclampsia?
deliver that baby!
what are the two most common obstetrical complications associated with preterm birth?
- spontaneous labor (45%)
- spontaneous rupture of membranes (35%)
what is the trend that Wolff wants us to know about birth outcomes?
making it to term matters
- the later in gestational age, the better chance the baby has of surviving to 1 year
what is the management of PPROM if > 34 weeks?
- GBS prophylaxis
- single corticosteroid course
what is the management of PPROM if 32 - 34 weeks?
- GBS prophylaxis
- single corticosteroid course
- antimicrobials to prolong latency
what is the management of PPROM if 24 - 32 weeks?
- GBS prophylaxis
- single corticosteroid course
- (no consensus on tocolytics)
- antimicrobials to prolong latency
- MgSO4 for neuroprotection
what is the management of PPROM if <24 weeks?
- GBS prophylaxis NOT RECOMMENDED
- single corticosteroid course
- (no consensus on tocolytics)
what heightens the risk of RDS?
preterm birth
- affects 40-50% of babies born before 32 weeks
- caused by surfactant deficit in immature lungs
what drugs are used in pre-term delivery to promote lung maturation and increase surfactant production?
corticosteroids
what are the indications for antenatal corticosteroids?
women between 24-36 weeks gestation with:
- threatened preterm labor
- antepartum hemorrhage
- preterm rupture of membranes
- conditions requiring c-section (preeclampsia, HELLP)
fluorinated steroid that hastens fetal lung development
- given in TWO doses IM in 24hr intervals (48hrs total)
betamethasone
fluorinated steroid that hastens fetal lung development
- given in FOUR doses IM in 12hr intervals (48hrs total)
dexamethasone
what is the MOA of endogenous fetal cortisol?
induces transcription of surfactant proteins in alveolar type 2 pneumocytes
why not administer cortisol to mom?
the placenta metabolizes/inactivates to CORTISONE (via 11b-hydroxy steroid dehydrogenase-2), so it doesn’t affect baby
NOTE: this means you can give cortisol if mom needs it for something and it won’t harm baby
which drugs should you use to delay contractions?
currently NO FDA approved drugs in US…
- nifedipine or indomethacin seem to be best choices currently available in US
NOTE: recommendation is to NOT combine tocolytics
calcium channel blocker
- MOA: blocks calcium influx thru voltage-gated channels (less calcium=less contraction)
- NOT FDA approved, but CCB’s are preferable to other comparative tocolytics
nifedipine
- causes flushing, headaches, dizziness
- no fetal side effects
what are the contraindications of nifedipine?
cardiac dz, maternal hypotension, avoid concomitant use with MgSO4
prostaglandin synthesase inhibitor
- MOA: blocks synthesis of PGFa2 (a potent stimulator of uterine contractions)
- NOT FDA approved
indomethacin
- causes nausea, heartburn, gastritis, proctitis, hematochezia, impaired renal function
- fetal side effects: constrics ductus arteriosus, pulmonary HTN, reversable decrease in renal function with oligohydramnios
what are the two main contraindication of indomethacin
significant renal or hepatic impairment
which tocolytic has been found to delay labor for 2-7 days?
- there is no evidence of benefit to fetus
- mother experience side effects: cardiac arrhythmias, pulmonary edema, myocardial ischemia, hypotension, tachycardia, SOA, hyperglycemia, hyperinsulinemia, tremor, NV)
terbutaline (beta-2 agonist)
what drug is used to prevent eclamptic seizures
- MOA: inhibits ACh release at uterine NMJ
- evidence does support its use for neuroprotection (appears to decrease risk for cerebral palsy)
- is a long-term drug of choice for tocolysis in US (but rarely used elsewhere)
magnesium sulfate
- in mom: causes skin flushing, palpitations, headaches, depressed reflexes, respiratory depression, impaired cardiac function
- in baby: muscle relaxation, rarely CNS depression
which b2-agonist used for tocolysis was approved by FDA in 1980, but was taken off the market in 1998?
ritodrine
- causes severe hallucinations
oxytocin inhibitor what is NOT available in the US?
atosiban
- causes maternal headaches, nausea
- no fetal side effects
synthetic PGE1 analog (similar to misoprostol) that MAINTAINS a patent ductus arteriosus
- indicated in pre-term infants with congenital heart defects
- infusion of PGE1 substitutes for and complements with PGE2
alprostadil
- adverse effects: hypotension, tachycardia, apnea
what drugs can be used to CLOSE a ductus arteriosus?
- signs of a PDA: baby isn’t eating well, is listless, breathes too fast and seems to be sweating too much
NSAIDs!
- indoemthacin
- recently, more likely ibuprofen
what drugs classes are contraindicated for HTN in pregnancy?
ALL ACE INHIBITORS/ARBs!!!
- they are lethal during 2nd/3rd trimesters
what is the first line tx for moderate HTN in pregnancy?
- oral a-methyldopa (a2 agonist)
- oral labetalol (a/b blocker)
what is the second line tx for severe HTN in pregnancy?
- parenteral labetalol
- hydralazine (arterial vasodilator)
- sodium nitroprusside (arterial/venous vasodilator)
