Repro; Pharm - Owen: Labor And Delivery 1&2; Kek

Front 1

what hormone hyperpolarizes smooth muscle membranes and prevents the release of arachidonic acid?

Back 1

progesterone - decreases prostaglandin synthesis - less contraction

Front 2

An increase in this hormone during pregnancy causes an increase in oxytocin receptor concentraion in the uterine muscle.

Back 2

estrogen

Front 3

what other types of receptors increase in the uterus during pregnancy?

Back 3

alpha adrenergic and angiotensin receptors -> this increases the sensitivity to contraction stimulation

Front 4

During labor, this system causes contractions of the uterus to aid in delivery.

Back 4

neuroendocrine system: fetal pressure on the cervix leads to local stimulation and spinal reflex -> oxytocin and prostaglandins are released -> even more contractions

Front 5

Uterine muscle has receptor binding sites for these substances that aid in contractions of the uterus?

Back 5

estrogen, oxytocin, alpha 1 adrenergic agonist, PGF2a, PGE2

Front 6

As pregancy continues what happens to the progesterone:estrogen ratio?

Back 6

early in pregnancy high:low; late in pregnancy low:high

Front 7

What is the fetus' role in raising amount of estrogen and thereby decreasing the progesterone to estrogen ratio?

Back 7

the fetus: increases estrogen production, produces large quantities of cortisol, increases quantities of oxytocin, prostaglandins and cytokines

Front 8

These drugs are used to enhance uterine contraction to induce or augment labor; they halso help in therapeutic abortions and post partum hemorrhage control.

Back 8

oxytocins (oxytocic agents)

Front 9

What agent prevent premature labor by suppressing myometrial smooth mucle contractions and inhibit the synthesis or release of PGs and/or other endogenous uterine stimulants?

Back 9

tocolytics

Front 10

Name 3 oxytocic agents.

Back 10

oxytocin, ergot alkaloids, and prostaglandins

Front 11

What are the synthetic names for the endogenous oxytocin and describe it.

Back 11

Pitocin, Syntocinon: oxytocin is produced in the paraventricular nucleus of the hypothalamus and is stored in the posterior pituitary, it circulates unbound and has a T1/2 of 15 minutes; it is inactivated by the liver and kidneys and is the DOC for inducing labor

Front 12

When are oxytocic agents used?

Back 12

pts with labor disorders; after incomplete abortion after 20 wks; after delivery of fetus using to control uterine hemorrhage; high doses will induce abortion; also an oxytocin challenge test

Front 13

inappropriate use of oxytocin may lead to what?

Back 13

uterine rupture, anaphylactoid and allergic rxns and maternal death

Front 14

What can prolonged stimulation of uterine contractions lead to in the fetus?

Back 14

uteroplacental insufficiency, sinus bradycardia, PVCs and arrhythmias, fetal death, and H2O intoxication (b.c its secondary ADH effects)

Front 15

this class of drugs interacts with adrenoreceptors, 5-HT receptors, and dopamine receptors and causes vasoconstriction of small vessels and stimulation of uterine smooth muscle as well as INHIBIT the release of EDRF (endothelial-derived relaxing factor)

Back 15

ergot alkaloids

Front 16

name the ergots used to treat postpartum hemorrhage after fetal delivery.

Back 16

ergonovine (stimulates cervical contraction) and methylergonovine - both stimulate uterine smooth muscle to contract and induce arterial vasoconstriction

Front 17

why are ergots used in mother's to be?

Back 17

they induce a sustained tetanic contraction where they: shorten the final stage of labor, reduce postpartum blood loss, expel placenta after delivery

Front 18

Explain the pharmokinetics of ergots (metabolized, excreted).

Back 18

metabolized by the liver, excreted by the kidneys, and can be found in breast milk (if prolonged use and the infant is nursing, it could vasoconstrict the infants vessels and cause death, gangrene, etc)

Front 19

Explain the ADRs with ergot alkaloids.

Back 19

hypertension, headaches, possible seizures, N/V, CP (chest pain), difficulty breathing, leg cramps

Front 20

What are contraindications for ergot alkaloids?

Back 20

angina pectoris, MI, pregnancy, hx of CVA, TIA, or hypertension

Front 21

This oxytocic agent is an eicosanoid and is made from arachidonic acid.

Back 21

Prostaglandin Agents

Front 22

Name the naturally occuring PGE2.

Back 22

dinoprostone

Front 23

Name the synthetic analogue of PGF2.

Back 23

carboprost tromethamine

Front 24

name the PGE1 analogue.

Back 24

misoprostrol

Front 25

what are the indications for using dinoprostone and carboprost tromethamine?

Back 25

to stimulate uterine smooth muscle contraction (**better than oxytocin thru 2nd trimester); induce abortion during wks 12-20; and dinoprostone causes cervical ripening (softening)

Front 26

what are the indications for misoprostol?

Back 26

cervical ripening and labor induction

Front 27

What are the ADRs to these prostaglandin agents?

Back 27

GI disturbances (NVD); transient fever, retained placental fragments, excessive bleeding, decrease diastolic BP, and headache

Front 28

In what types of patients should you be cautious in giving prostaglandins?

Back 28

asthmatics, cervicitis, vaginitis, increased or decreased BP, anemia, jaundice, diabetes, and epilepsy

Front 29

In what types of patients should you not used prostaglandins in?

Back 29

acute PID, drug hypersensitivity, and active renal, hepatic, or CV disorders

Front 30

What is potentially carcinogenic and should NOT be used with oxytocin and why?

Back 30

prostaglandins - with oxytocin there is a risk of uterine rupture

Front 31

These group of drugs causes uterine relaxationa and are used to inhibit labor early in gestation.

Back 31

tocolytics (uterine relaxants)

Front 32

What is premature labor?

Back 32

labor occurs before week 37

Front 33

List the ADRs of tocolytics in the mother.

Back 33

Pulmonary edema, MI, respiratory arrest, cardiac arrest, and death

Front 34

List the ADRs of tocolytics in the newborn.

Back 34

respiratory distress, intraventricular hemorrhage and necrotizing enterocolitis

Front 35

List the absolute contraindications of tocolytics.

Back 35

acute fetal distress, chorioamnionitis, eclampsia or severe preeclampsia, fetal demise, maturity, and maternal hemodynamic instability

Front 36

Name some agents that inhibit contractions and thus prolong pregnancy.

Back 36

alcohol, B2 adrenergic agonist, Mg2+ sulfate, PG synthesis inhibitors, Ca2+ channel blockers and hydroxyprogesterone

Front 37

How does alcohol inhibit contractions?

Back 37

it ihibits oxytocin release from the pituitary (no longer used)

Front 38

Name the 2 B2 adrenergic agonist that prevent premature labor 20wks or more in gestation and can arrest preterm labor for 48-72 hours.

Back 38

ritodrene and terbutaline

Front 39

What is the mechanism of action of B2 adrenergic receptor activity?

Back 39

activates adenylate cyclase, increases cAMP, activates cAMP dependent protein kinase, decreases intracellular Ca2+, reduces the effect of calcium on muscle contraction

Front 40

what is given to premature babies to help inflate their underdeveloped lungs?

Back 40

corticosteroids

Front 41

What are the Side-effects of B2 adrenergic agonists?

Back 41

they may have residual B1 receptor (not completely selective) activity such as palpitations, tremors, N/V, nervousness, anxiety, CP, SOB, ECG changes, hyperglycemia, hypokalemia, hypotension; SERIOUS SEs: Pulmonary edema, cardiac insufficiency, arrhythmias, MI, death

Front 42

When you give _____ you have to monitor CV responses in mother and fetus.

Back 42

ritodrene - preference for B2

Front 43

what is special about terbutaline and its package labeling?

Back 43

PDR says it shouldn't be used for tocolysis (uterine relaxation) but it is in the hospital setting

Front 44

Of the 2 tocolytics, which one commonly leads to hypoglycemia?

Back 44

terbutaline

Front 45

of the 2 tocolytics, which one commonly leads to tachycardia and hypotension?

Back 45

ritodrine

Front 46

this drug not only prevents uterine contraction but prevents convulsions in preeclampsia by competing for Ca++ binding sites (decreasing Ca++uptake); it also directly uncouples excitation/contraction in myometrial cells thru inhibition of cellular action potentials.

Back 46

Magnesium sulfate

Front 47

Magnesium sulfate is preferred over Beta adrenergic agents in what types of patients?

Back 47

diabetics, HTN, Heart dz, and hyperthyroidism

Front 48

With increasingly toxic levels of magnesium you can get the following:

Back 48

(need at least 5.5mEq/L) first get loss of pateller reflex -> respiratory depression -> respiratory paralysis -> cardiac arrest

Front 49

name some other (less serious) SE of Mg2+ sulfate.

Back 49

sweating, dry mouth, dizzy, palpitations, warmth, nausea, nystagmus, ECG changes, flushing, vomiting, headache

Front 50

Since prostaglandins increase contractions it makes sense that NSAIDs like _____ prolong pregnancy.

Back 50

Indomethacin - decrease PG production, prolong spontaneous labor, interrupt premature labor

Front 51

what is indomethacin commonly used for after delivery in a fetus. Why may this be a problem during pregnancy?

Back 51

indomethacin is used to close a premature baby's fetal ductus arteriosus; if the pregnant mother is taking indomethacin to prolong the fetal growing, it could prematurely close the FDA

Front 52

What are the possible problems with a pregnant woman taking long term indomethacin?

Back 52

the newborm may have primary pulmonary hypotension and increased incidence of intraventricular hemorrhage

Front 53

This Ca++ channel blocker impairs Ca++ entry into myometrial cells and thus prevents contraction.

Back 53

nifedipine (more studies needed)

Front 54

When during pregnancy is hydroxyprogesterone used in preventing preterm labor and why is it not currently used much.

Back 54

it is used during weeks 12-37 but may have teratogenic potentials

Front 55

Name some other unapproved drugs that are under study to be used as tocolytics.

Back 55

diazoxide (anti-HTN, relaxes smooth muscle); atosiban (oxytocin antagonist, inhibits binding); prolactin?, bromocriptine (dopamine agonist - supresses prolactin)

Front 56

Name the antiprogestin agent that blocks the binding of progesterone and is an abortive agent used in early pregnancy.

Back 56

mifepristone (RU 486)