Uterine Stimulahts And Relaxants Flashcards
Are there contractions in the first to trimesters of pregnancy , why
No
Inhibitor reaction of progesterone in the uterine musculature
What is false labor
When contraction goes to the extent of feeling like onset of labor
What doesparturition requires
Cervical canal dilation
uterine smooth muscle contraction
Hormone responsible for cervical canal dilation
Relaxin
Where is relaxin produced
In the corpus luteum and the placenta
Hormone responsible for the association of connective tissue between the pelvic bones
Relaxin
Hormones responsible for contractions during labor
Oxytocin and prostagland
What causes contraction : oxytocin increasing levels or oxytocin receptors increasing level
Oxytocin receptors increasing level
The release of this hormone promotes prostaglandin production
Oxytocin
This compound is a powerful myometrial stimulants
Prostaglandins
Type of uterine Stimulants
Oxytocin
Ergonovine, methylergonovine maleate
prostaglandin analogues
Where is oxytocin produced
Hypothalamus and released by the posterior pituitary
Mechanism of action of Oxytocin
Direct stimulation of oxytocin receptors on the myometrial cell
Half life of oxytocin
15 minutes
Drug of choice to induce labor
Ox
Percentage of patients that progressed into labor after administration of oxytocin
80
Inappropriate use of oxytocin lead to
Uterine rupture
Anaphylactoid rxns
Maternal death
Fetal adverse rxns
Source of ergonovine
Ergot
Action of Ergonovine
Stimulate smooth muscle directly which
induces sustained tetanic contraction
Inhibit endothelial derived relaxation factor
Induce arterial vasoconstriction
Minor action on CNS
I
Ergonovine act on which receptors
Partial agonists at alpha adrenergic , dopamine and serotonin receptors
Mode of administration of Ergonovine and methylergonovine
IM
IV
Unwanted effect of IV administration of Ergonovine
Severe hypertension
Contra indications of Ergonovine
Angina pectoris
myocardial infarction
transient ischemic attack
hypertension
Examples of prostaglandin analogues
Dinoprostone
Carboprost tromethamine
Misoprostol
What is dinoprostome
Naturally occurring prostaglandin E2 found in mammals tissues
What is carbosprost tromethanien
Naturally occurring prostaglandin F2 found in mammals tissues
Can prostaglandin analogues cause abortion between weeks 12 to 20 weeks
Yes
Dinorprostone action
Cervical dilation
stimulation of the uterus
alternative to oxytocin labor induction
Where do you place dinoprostone
Cervix, posterior formix
Dinoprostone action
Cervical dilation
Stimulation of uterus
This prostaglandin analog given intramuscular cause immediate and sustained uterine contraction Which has saved a life of number of women
Carboprost
Misoprostol uss
Cervical dilation
Uterine stimulant activity
Peptic ulcer disease
Adverse effects of prostaglandin Analogues
Nausea vomiting diarrhea Transient fever retain placental fragments excessive bleeding decreased diastolic blood pressure headache
Why cannot use oxytocin with prostaglandin analogue
Because possibility of uterine rupture
Drugs used to inhibits early labor
uterine relaxants
Second name of uterine relaxants
Tocolytics
Example of tocolytics
ethanol magnesium sulfate prostaglandin inhibitors calcium channel blockers hydroxy progesterone beta2 adrenergic agonist
Adverse events of tocolytics
Pulmonary edema myocardial infarction respiratory arrest cardiac arrest death
Do we still use intravenous ethanol to inhibits premature labor
No
Action of ethanol
Inhibits oxytocin released from PT cherry which decreases myometrial contractility
MOA magnesium sulfate
Uncouples excitation contraction in myometrial cells through the inhibition of cellular action potentials
decreases calcium uptake by competing for binding sites which reduces intracellular calcium
At which plasma level should you maintain magnesium for tocolysis to to maybe occur
5.5meq/l
Side effects of magnesium sulfate
Cardiac arrest sweating warmth Flushing dry mouth nausea vomiting dizziness nystagmus headache palpitations
B2 adrenergic agonists are they effective in premature labor
Not completely
How long can beta2 adrenergic agonist arrest preterm labor
48 to 72
Percentage of increase in probability of survival for the new born with a 2 day delay in delivery due to beta2 adrenergic
10 to 15%
Mode of action of beta2 adrenergic agonist
Binds to the reçeptors in the Myometrium and activates cyclic AMP dependent protein kinase and decreases intracellular calcium leading to myometrial muscle relaxation
Side effects of beta-2 adrenergic agonist
Palpitations Tremor nausea vomiting nervousness hyperglycemia hypokalemia
Classical example of beta-2 adrenergic agonist
Terbutaline
Ritodrine
Can the combination of terbutaline in magnesium sulfate cause cardiac disturbances
Yes
Side effects of Terbutaline
Tachycardia
hyperglycemia
hypokalemia
What does administration of terbutaline
Subcutaneous intravenous oral
Example of prostaglandin inhibitors
Indomethacin - NSAIDS
What does administration of indomethacin
Rectal
oral
Side effects of indomethacin
Decrees amniotic fluid volume
oligohydramnios
Intraventricular hemorrhage in the newborn
Which calcium channel blocking is used as uterine relaxants
Nifedipine
Action of nifedipine
Impair entry of calcium into my metro cells and inhibits contractility
When do you use hydroxy progesterone as a uterine relaxants
As a prophylaxis in women who are a high-risk category for premature delivery
Why is the use of hydroxy progesterone limited
Teratogenic but I
