Module 1: Chapter 53 Drugs Affecting Uterine Motility

Question 1

what homrone is responsible for uterine contractions

Answer 1

oxytocin

Question 2

The induction of labor is related to what hormone

Answer 2

oxytocin

Question 3

the oxytocin receptors that are located in the _______ increase during ______ and reach peak levels at _____

Answer 3

endometerium
labor
birth

Question 4

what also has a role in preparing the uterus for labor and delivery

Answer 4

prostaglandins

Question 5

what prostaglandin leads to sensitization of the myometrium to oxytocin

Answer 5

prostaglandin E2

Question 6

what does prostaglandin E2 do

Answer 6

leads to sensitization of the myometrium to oxytocin

Question 7

what are the three phases of uterine contractions

Answer 7

incremental phase
stable phase
third phase

Question 8

what occurs in the incremental phase of uterine contractions

Answer 8

oxytocin receptors endometrium wait for oxytocin

Question 9

what happens in teh stable phase of uterine contractions

Answer 9

oxytocin receptors are fully occupied

Question 10

what occurs in the third phase of uterine contractions

Answer 10

uterine tetany (prolonged contractions)

Question 11

what are the two categories of obstetric situations that require drug administration to intitate the onset of contractions

Answer 11

1) labor that does not begin at term

2) pregnancy that is determental to the patient or her fetus

Question 12

what is the name for synthetic forms of the endogenous hormone oxytocin

Answer 12

oxytocic drugs

Question 13

where is the hormone oxytocin produced

Answer 13

posterior pituitary

Question 14

what do oxytocic drugs produce

Answer 14

uterine contractions and milk ejection for breast-feeding

Question 15

what is the prototype drug for oxytocics

Answer 15

pitocin

Question 16

what are the pharacotherapeutics for oxytocin

Answer 16

given by IV drip infusion to initate or augment (improve) labor contractions

Question 17

how is oxytocin administered

Answer 17

via IV

Question 18

what is the onset for oxytocin

Answer 18

immediate

Question 19

how is oxytocin eliminated

Answer 19

through the liver, kidney and mammary glands

Question 20

does synthetic exogenous oxytocin have the same effects on the body as natural endogenous oxytocin

Answer 20

yes

Question 21

what are some contraindications and precautions for oxytocin

Answer 21

cephalopelvic disproportion and unfavorable fetal positions

Question 22

what are some adverse effects for oxytocin

Answer 22

nausea, vomiting, uterine hypteronicity and cardiac arrhythmias

Question 23

what drugs have interactions with oxytocin

Answer 23

sympathomimetic drugs

Question 24

what should we assess for before giving oxytocin

Answer 24

assess pelvic adequacy
assess druation of pregnancy
consider the patient risk of water intoxication
assess environment where drug will be given

Question 25

what are two ways to maximize thereapeautic effects of oxytocin

Answer 25

assess cervical ripening using the bishop scoring system | use an infusion pump for precise administration of oxytocin

Question 26

what are two ways to minimize adverse effects of oxytocin

Answer 26

piggyback the diluted oxytocin solution into a primary IV line The FHR monitor continuously records the patients uterine contraction pattern

Question 27

what are the most severe adverse effect of oxytocin

Answer 27

water intoxication uterine rupture permanent CNS damage to the fetus

Question 28

what are 5 other adverse effects of oxytocin to the fetus

Answer 28

``` preamture ventricular contractions arrhythmias impaired fetal oxygenation premanet brain or CNS damage death ```

Question 29

what is the class of drugs called that inhibit uterine activity

Answer 29

tocolytics

Question 30

what is the medical complication that requires the use of tocolytics

Answer 30

preterm labor

Question 31

what gestational time frame are tocolytics used

Answer 31

when true labor begins after 20 weeks and usually before completion of the 34th gestational week

Question 32

what is the prototype drug for tocolytics

Answer 32

terbutaline (Bretheine)

Question 33

what is the off-label therapeutic use of terbutaline

Answer 33

control preterm labor in pregnancies of 20-34 weeks

Question 34

how is terbutaline administered

Answer 34

SC or orally

Question 35

how does terbutaline work

Answer 35

beta-receptor agonist (stimulant) that selectively prefers the beta-2 receptors over beta-1 receptors

Question 36

when is terbutaline contraindicated

Answer 36

before the 20th week of pregnancy

Question 37

what are the adverse effects of terbutaline

Answer 37

``` tachycardia hypotension dyspnea nervousness transient hyperglycemia pulmonary edema cerebral and myocardial ischemia N/V ```

Question 38

what other class of drugs has interactions with terbutaline

Answer 38

beta stimulants

Question 39

what pregnancy category is terbutaline

Answer 39

category B

Question 40

to maximize terbutaline effects when should you begin drug therapy

Answer 40

as soon as possible after preterm labor is diagnosed

Question 41

what should be done to minimize adverese effects

Answer 41

closely monitor the patients fluid status to avoid fluid overload

Question 42

what should be done if a patient demonstrates signs of adverse effects when being treated with terbutaline

Answer 42

dosage should be decreased

Question 43

why side should a patient lie on when being administered terbutaline

Answer 43

left | decrease chance of hypotension and promote fetal circulation

Question 44

T or F: terbutaline inhibits contractility of uterine smooth muscle by inhibition of the alpha receptors in the uterine smooth muscle

Answer 44

True: terbutaline is a beta-receptor agonist (stimulant) that selectively prefers the beta-2 over beta-1 receptors simulation of these receptors inhibits contractility of uterine smooth muscle