Oxytocics And Tocolytics

Front 1

Oxytocic agents include oxytocin, prostaglandins, ergot alkaloids and a progesterone receptor antagonist.

Name the prostaglandin agents.
Name the ergot alkaloid agents.
Name the progesterone receptor antagonist.

Back 1

Oxytocic agents include:

(1) oxytocin

(2) prostaglandins: PGE2, 15-methylprostaglandin F2, misoprostol

(3) ergot alkaloids: ergonovine, methylergonovine

(4) mefipristone

Front 2

In what trimester is the uterus most sensitive to oxytocin?

Back 2

3rd trimester

Front 3

If your goal is to stimulate uterine activity in the first 2 trimesters, this oxytocic agent would work best:

a) prostaglandin
b) oxytocin
c) ergot alkaloid

Back 3

If your goal is to stimulate uterine activity in the first 2 trimesters, this oxytocic agent would work best:

a) prostaglandin

Front 4

What are the physiological roles of oxytocin?

Where does this hormone come from?

Is it similar to other hormones?

Back 4

Oxytocin stimulates the myoepithelium lining the ductwork of teh breast to contract to make milk available for suckling. It also plays a role in the maintenance of labor.

It comes from the posterior pituitary and is released due to mechanical stretch of teh uterus, vagina or breast.

Oxytocin is structurally similar to ADH.

Front 5

Describe oxytocin's neuroendocrne reflex.

Back 5

The afferent neural arm brings information to the CNS upon tactile stimulation of the breast, stretch of the vagina or uterus, or auditory stimulation. The efferent, endocrine arm of the reflex then produces oxytocin secretion.

Front 6

What is the clinical indication for oxytocin injection?

Does it have a long or short half-life? Why is this important?

Back 6

Oxytocin injections allow for excellent control of uterine contractility during labor induction. Injections can also minimize post-partum blood loss by stimulating sustained contractions.

Oxytocin has a short half-life, which allows for excellent control of contractility and the avoidance of uterus rupture or fetal death if too much oxytocin is injected.

Front 7

Name the 3 oxytocic prostaglandin agents.

What is the indication for these prostaglandins?

Back 7

Prostaglandins include PGE2 or dinoprostone, 15-methylprostaglandin F2, and misoprostol.

These agents contract both the gravid and non-gravid uterus. They are also useful as abortifacients, for ripening the cervic and for post-partum bleeding.

Front 8

Name the 2 ergot alkaloid oxytocic agents.

What is the indication for these agents?

Back 8

Oxytocic ergot alkaloids include ergonovine and methylergonovine.

These agents are NOT used to induce labor. Instead they are administered after labor to control post-partum bleeding.

Front 9

What are the indications for inducing labor?

Back 9

Induce labor in a patient if the risk of continuing pregnancy is greater than the risks associated with inductions. The following clinical scenarios are indications for induction:

1) diabetes mellitus
2) hx of intrauterine demise, especially late in pregnancy
3) prolonged pregnancy >40 weeks
4) hypertension
5) bleeding complications
6) preeclampsia

Front 10

What are the contraindications for inducing labor?

Back 10

Contraindications:

1) fetopelvic disproportion
2) unfavorable presentation
3) invasive cervical cancer

Front 11

All of the following are associated uses of oxytocic agents. For each use/scenario, identify the appropriate agent that should be used..

1) maintenance of labor
2) post-partum bleeding control
3) ripening of cervix
4) fetal stress test
5) abortion

Back 11

1) maintenance of labor - oxytocin

2) post-partum bleeding control - oxytocin, PGs, ergots

3) ripening of cervix - small doses of dinoprostone

4) fetal stress test - oxytocin

5) abortion - prostaglandins with or without RU-486/mefipristone

Front 12

What is the fetal stress test and what oxytocic agent is used to perform it?

Back 12

The fetal stress test involves administering oxytocin to produce contractions. If the fetal heart rate slows down upon oxytocin administration and uterine contractions, this is indication that the baby is in distress.

Front 13

What are the adverse reactions associated with oxytocic agents?

Back 13

(1) uterine tetany, which may cause uterine rupture or fetal death

(2) H20 intoxication due to the ADH activity of oxytocin

Front 14

What is the general purpose of administering tocolytics to a pregnant woman?

Back 14

Tocolytics are uterine relaxants and prolong pregnancy until the fetus is viable.

Front 15

Under what circumstances are tocolytics administered?

Back 15

If a woman is at risk of going into labor before the fetus is viable, she must be put on bedrest first and foremost.

If she begins to go into premature labor before 34 weeks gestation, has a 3-4cm cervical dilation and no contraindications, then tocolytics can be administered.

Front 16

List the various tocolytic agents discussed in class.

Back 16

Tocolytic agents include:

--MgSO4
--beta2 agonists (ritodrine, terbutaline)
--indomethacin
--nefedipine

Front 17

In general, what are oxytocics? What are examples of oxytocics?

In general, what are tocolytics? What are examples of tocolytics?

Back 17

Oxytocics are agents that stimulate uterine contraction. Examples: estrogen, oxytocin, prostaglandins,

Tocolytics are agents that relax the uterus. Examples: progesterone, B-agonists