Module 1: Chapter 53 Drugs Affecting Uterine Motility Flashcards
what homrone is responsible for uterine contractions
oxytocin
The induction of labor is related to what hormone
oxytocin
the oxytocin receptors that are located in the _______ increase during ______ and reach peak levels at _____
endometerium
labor
birth
what also has a role in preparing the uterus for labor and delivery
prostaglandins
what prostaglandin leads to sensitization of the myometrium to oxytocin
prostaglandin E2
what does prostaglandin E2 do
leads to sensitization of the myometrium to oxytocin
what are the three phases of uterine contractions
incremental phase
stable phase
third phase
what occurs in the incremental phase of uterine contractions
oxytocin receptors endometrium wait for oxytocin
what happens in teh stable phase of uterine contractions
oxytocin receptors are fully occupied
what occurs in the third phase of uterine contractions
uterine tetany (prolonged contractions)
what are the two categories of obstetric situations that require drug administration to intitate the onset of contractions
1) labor that does not begin at term
2) pregnancy that is determental to the patient or her fetus
what is the name for synthetic forms of the endogenous hormone oxytocin
oxytocic drugs
where is the hormone oxytocin produced
posterior pituitary
what do oxytocic drugs produce
uterine contractions and milk ejection for breast-feeding
what is the prototype drug for oxytocics
pitocin
what are the pharacotherapeutics for oxytocin
given by IV drip infusion to initate or augment (improve) labor contractions
how is oxytocin administered
via IV
what is the onset for oxytocin
immediate
how is oxytocin eliminated
through the liver, kidney and mammary glands
does synthetic exogenous oxytocin have the same effects on the body as natural endogenous oxytocin
yes
what are some contraindications and precautions for oxytocin
cephalopelvic disproportion and unfavorable fetal positions
what are some adverse effects for oxytocin
nausea, vomiting, uterine hypteronicity and cardiac arrhythmias
what drugs have interactions with oxytocin
sympathomimetic drugs
what should we assess for before giving oxytocin
assess pelvic adequacy
assess druation of pregnancy
consider the patient risk of water intoxication
assess environment where drug will be given
what are two ways to maximize thereapeautic effects of oxytocin
assess cervical ripening using the bishop scoring system
use an infusion pump for precise administration of oxytocin
what are two ways to minimize adverse effects of oxytocin
piggyback the diluted oxytocin solution into a primary IV line
The FHR monitor continuously records the patients uterine contraction pattern
what are the most severe adverse effect of oxytocin
water intoxication
uterine rupture
permanent CNS damage to the fetus
what are 5 other adverse effects of oxytocin to the fetus
preamture ventricular contractions arrhythmias impaired fetal oxygenation premanet brain or CNS damage death
what is the class of drugs called that inhibit uterine activity
tocolytics
what is the medical complication that requires the use of tocolytics
preterm labor
what gestational time frame are tocolytics used
when true labor begins after 20 weeks and usually before completion of the 34th gestational week
what is the prototype drug for tocolytics
terbutaline (Bretheine)
what is the off-label therapeutic use of terbutaline
control preterm labor in pregnancies of 20-34 weeks
how is terbutaline administered
SC or orally
how does terbutaline work
beta-receptor agonist (stimulant) that selectively prefers the beta-2 receptors over beta-1 receptors
when is terbutaline contraindicated
before the 20th week of pregnancy
what are the adverse effects of terbutaline
tachycardia hypotension dyspnea nervousness transient hyperglycemia pulmonary edema cerebral and myocardial ischemia N/V
what other class of drugs has interactions with terbutaline
beta stimulants
what pregnancy category is terbutaline
category B
to maximize terbutaline effects when should you begin drug therapy
as soon as possible after preterm labor is diagnosed
what should be done to minimize adverese effects
closely monitor the patients fluid status to avoid fluid overload
what should be done if a patient demonstrates signs of adverse effects when being treated with terbutaline
dosage should be decreased
why side should a patient lie on when being administered terbutaline
left
decrease chance of hypotension and promote fetal circulation
T or F: terbutaline inhibits contractility of uterine smooth muscle by inhibition of the alpha receptors in the uterine smooth muscle
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
