drugs acting on uterus

Question 1

goal of cervical ripening

Answer 1

reduce rate of failed induction

Question 2

cervical ripening drugs

Answer 2

1) dinoprostone

2) misoprostol

Question 3

use of dinoprostone/misoprostol

Answer 3

promote cervical ripening in women with unfavorable cervices

may also initiate labor - and reduce need for oxytocin

Question 4

dinoprostone

Answer 4

PGE2

Question 5

misoprostol

Answer 5

PGE1

Question 6

prostaglandins AE

Answer 6

tachysystole
fever/chills
v/d

Question 7

oxytocin use

Answer 7

induce labor when cervix is ripe

ripening agent should be used before when women has unfavorable cervix

Question 8

oxytocin

Answer 8

peptide hormone
secreted by posterior pituitary

IV infusion

Question 9

oxytocin MOA

Answer 9

G(q) = PLC – Ca2+ released from SR

ALSO activation of VG Ca2+ channels – calcium induced calcium release

Ca2+ activates MLCK = contraction

oxytocin also increases PG synthesis = more contractions

Question 10

oxytocin AE

Answer 10

sustained contractions = fetal distress, placental abruption (with too high doses)

activation of vasopressin receptors = fluid retention/water intoxication –> hyponatremia, HF, seizures

Question 11

management of postpartum hemorrhage

Answer 11

oxytocin (IV or IM)
ergot alkaloids
prostaglandins

Question 12

methylergonovine

Answer 12

ergot alkaloids - partial agonist at alpha adrenergic and serotonin receptors

uterus is very sensitive to ergot alkaloids during pregnancy

Question 13

methylergonovine AE

Answer 13

minimal - HTN, HA, n/v, CP

Question 14

methylergonovine contraindications

Answer 14

pregnancy
angina
MI
CVA
HTN

Question 15

carboprost tromethamine

Answer 15

PGF-2alpha

IM admin

Question 16

1st line postpartum hemorraghe

Answer 16

oxytocin

Question 17

2nd line for postpartum hemorrhage

Answer 17

methylergonovine, carboprost tromethamine, misprostone

Question 18

tocolytics

Answer 18

uterine relaxants

if gestation <37 weeks

given to have time for glucocorticoids to work to develop lungs (if <34 weeks)

Question 19

magensium sulfate

Answer 19

tocolytic
works like calcium antagonist

uncouple excitation contraction in myometrial cells - via inhibition of cell AP

Question 20

indomethacin

Answer 20

tocolytic

block PG (via NSAID)
only NSAID used for this purpose

Question 21

nifedipine

Answer 21

tocolytic

CCB - prevent SM contraction - no activation of MLCK

Question 22

tocoloytic DOC

Answer 22

none

Question 23

other tocolytics

Answer 23

atosiban

b2 agonist

Question 24

magnesium sulfate AE

Answer 24

respiratory depression
cardiac arrest
can cross placenta = respiratory/motor depression of baby

Question 25

indomethacin AE

Answer 25

more neonate AE than maternal**

crosses placenta = oligohydramnios d/t dec fetal RBF if used for more than 48 hours

premature PDA closure

not recommended after 32 weeks

Question 26

nifedipine AE

Answer 26

maternal tachycardia, palpitations, flushing, HA, dizzy

Question 27

atosiban

Answer 27

competitive antagonist at oxytocin receptors

Question 28

b2 agonists as tocolytic

Answer 28

AC = inc cAMP = PKA activated
–> smooth muscle MLCK phosphorylated = lower affinity for Ca2+ calmodulin complex = no phosphorylated myosin - SM relaxed

Question 29

b2 agonist AE

Answer 29

limited to be given 72 hours to tx preterm labor

palpitations
tremor
n/v
anxiety
hypokalemia
hypotension
pulmonary edema

**black box warning = terbutaline against use in preterm labor - death and serious AE