Uterine Drugs

Question 1

What 4 things cause uterine contraction?

Answer 1

Estrogen, prostaglandins, oxytocin, stretching

Question 2

What 4 things cause uterine relaxation?

Answer 2

beta-adrenergic drugs, progesterone, alcohol, MgSO4

Question 3

What increases in # and sensitivity prior to labor and delivery?

Answer 3

Oxytocin receptors

Question 4

During the 2nd trimester, the uterus is resistant to stimulation but what can cause strong labor like contractions?

Answer 4

Prostaglandins

Question 5

What is the most common cause of postpartum hemorrhage?

Answer 5

Uterine atony
(lack of myometrial contractions fail to squeeze and constrict the spiral arteries)

Question 6

How much BF is getting to the placenta at term?

Answer 6

~500mL/ min

Question 7

How much blood loss is considered to be postpartum hemorrhage for both vaginal delivery and C-section?

Answer 7

Vaginal delivery ~500mL

C-section ~1000mL

Question 8

What is 1st line treatment for postpartum hemorrhage?

Answer 8

Massage

Question 9

In regards to premature labor, the earlier the preterm, the greater the what?

Answer 9

Risks for the baby

Question 10

What is the most common RF for premature labor?

Answer 10

Previous preterm labor or preterm birth

Question 11

If preterm labor needs to happen before the 37th week, what drugs should be given and why?

Answer 11

Give corticosteroids to induce lung development

Question 12

Pitocin drug class?

Answer 12

Oxytocin

Question 13

Syntocin drug class?

Answer 13

Oxytocin

Question 14

Ergonovine Maleate (Ergotreate) drug class?

Answer 14

Ergot alkaloids

Question 15

Dinoprostone drug class?

Answer 15

Prostaglandins

Question 16

Carboprost tromethamine drug class?

Answer 16

Prostaglandins

Question 17

Misoprostol drug class?

Answer 17

Prostaglandins

Question 18

Tranexamic acid drug class?

Answer 18

Non-uterotonic drugs

Question 19

Magnesium drug class?

Answer 19

Tocolytic agents

Question 20

Nifedipine drug class?

Answer 20

Tocolytic agents

Question 21

Indomethacin drug class?

Answer 21

Tocolytic agents

Question 22

Progesterone drug class?

Answer 22

Tocolytic agents

Question 23

What is the MOA for Pitocin and Syntocin?

Answer 23

Oxytocin receptor agonists

Question 24

What is DOC for inducing labor at term (if needed)?

Answer 24

Pitocin and Syntocin given IV

cause timed contractions = more physiological

Question 25

What is the use for Pitocin and Syntocin given IM?

Answer 25

Prevention of hemorrhage (if not already on IV, and 2nd line after massage

Question 26

What is the use for Pitocin and Syntocin given via the nasal route?

Answer 26

Milk let-down reflex

Question 27

What is the half life for Pitocin and Syntocin?

Answer 27

Short- 1-6 min | allows for on-off timed contractions

Question 28

What are the SEs of Pitocin and Syntocin? (4)

Answer 28

Water intoxication, uterine rupture, anaphylaxis, sinus bradycardia of fetus (Water intoxication and uterine rupture only with large doses, sinus bradycardia due to forceful contractions)

Question 29

What is the contraindication to Pitocin and Syntocin?

Answer 29

Any non-vaginal delivery

Question 30

What is the MOA for Ergonovine Maleate (Ergotreate)?

Answer 30

Contraction of uterine smooth muscle through activation of serotonin and alpha-adrenergic receptors ("always on")

Question 31

When is Ergonovine Maleate (Ergotreate) used?

Answer 31

After completion of labor and delivery of placenta to produce firm uterine contractions and decrease uterine bleeding, 3rd line (after massage and oxytocin)

Question 32

How long after Ergonovine Maleate (Ergotreate) given IV is it active?

Answer 32

Rapid action (30-40 seconds)

Question 33

How long after Ergonovine Maleate (Ergotreate) given orally is it active?

Answer 33

10 min

Question 34

How long do the actions of Ergonovine Maleate (Ergotreate) last?

Answer 34

Several hours

Question 35

What is the SE for Ergonovine Maleate (Ergotreate)?

Answer 35

Transient HTN (contracts all smooth muscle)

Question 36

What is the contraindication for Ergonovine Maleate (Ergotreate)? (3)

Answer 36

Never used to induce labor, peripheral vascular/ CAD

Question 37

What is the DOC for inducing abortions during the 2nd trimester?

Answer 37

Prostaglandins

Question 38

What drug is used for expulsion of uterine contents (abortion) and is 4th line (after massage, oxytocin, and ergots) for postpartum atony?

Answer 38

Prostaglandins

Question 39

What is the use of Dinoprostone in the gel form?

Answer 39

Cervical ripening prior to delivery at term

Question 40

Which of the Prostaglandins is associated with the worst diarrhea as a SE?

Answer 40

Dinoprostone (black box warning)

Question 41

What are the SEs of the prostaglandins? (3)

Answer 41

GI disturbances, vomiting, diarrhea | also fever, chills, HA

Question 42

What are the contraindications for use of Prostaglandins for abortions? (7)

Answer 42

``` Acute pelvic inflammation Acute cardiac/ pulm/ renal/ hepatic disease Asthma HTN Anemia Jaundice Epilepsy ```

Question 43

What is the MOA for Tranexamic acid?

Answer 43

Antifibrinolytics = inhibits plasminogen activation

Question 44

What is the use for Tranexamic acid?

Answer 44

Limits mortality from postpartum hemorrhage, given in combo with uterotonic therapy (oxytocin, ergots, PGE)

Question 45

How is Tranexamic acid given with standard uterotonic therapy?

Answer 45

IV

Question 46

What is the MOA for magnesium?

Answer 46

Relaxes uterus

Question 47

What is considered "1st line" for prevention of premature labor or to delay premature labor until the 37th week?

Answer 47

magnesium

Question 48

What drug can prevent convulsion in preeclampsia and is used to treat preeclampsia?

Answer 48

magnesium

Question 49

How is magnesium administered?

Answer 49

IV and slowly (hospital only)

Question 50

What are the SEs of magnesium?

Answer 50

Flu-like sxs

Question 51

What is the MOA of Nifedipine?

Answer 51

L-type calcium channel blocker (inhibits Ca2+ influx/ smooth muscle contractions)

Question 52

What is Nifedipine used for?

Answer 52

Prevents premature labor or delays premature labor until 37th week

Question 53

How is Nifedipine administered?

Answer 53

Orally (can be given at home)

Question 54

What is the MOA for indomethacin?

Answer 54

Inhibits COX enzyme (reduction of prostaglandin synthesis)

Question 55

When is indomethacin used?

Answer 55

Prevents premature labor or delays premature labor until 37th week

Question 56

What are the SEs of indomethacin? (2)

Answer 56

Maternal GI irritation, partial closure of fetal ductus arteriosus (usually remains open by PGE)

Question 57

What is progesterone used for with respect to labor?

Answer 57

Delays premature labor (until 37th week) when given prophylactically from 16th-37th week to women with a history of premature labor

Question 58

Why are progesterone NOT effective for acute treatment with respect to labor and delivery?

Answer 58

Work via nuclear receptors (slow reaction) and because progesterone is already naturally present (rises throughout pregnancy)