Hellkatz: Uterine Drugs Flashcards
What drugs induce labor, control postpartum hemorrhage, produce uterine contractions after a C-section and many ohter things?
oxytocics
What stimulates smooth muscle contraction?
increased intracellular Ca
Where are oxytocin and pitocin synthesized and secreted?
synthesized in paraventricular and supraoptic nuclei of the hypothalamus>
transported via neurons>
secreted from vesicles in PP
What causes the release of oxytocin and pitocin?
cervical dilation
mechanical stimulation of vagina/uterus
suckling reflex
What type of receptor do oxytocin and pitocin stimulate?
OTR is a GPCR> increases PLC
What recetpor is present in myoepithelial cells of mammary glands, pregnant myometrium and the CNS?
OTR
What inhibits the release of oxytocin and pitocin?
ethanol
What is used to promote uterine contractions and milk let down?
Oxytocin and pitocin
**can also be used as an antidiuretic at high concentrations (like ADH)
Can be oxytocin and pitocin be given orally?
NO it’s a peptide so it can’t be
What is the drug of choice for labor induction ?
pitocin (synthetic oxytocin)
What is pitocin used for?
Post-due date
Augment dysfunctional labor
Speed up labor in risk situations (chronic HTN, preeclampsia)
Milk let down postpartum
stimulate uterine motility postpartum to reduce bleeding
What is synthesized form AA by COX and rises in AF during pregnancy?
PGs
What promotes ripening of cervix (d/t numerous biochemical processes that rearrange the collagen molecules) and uterine contraction?
PGE2
What causes uterine contractions?
PGF2
What reduces oxytocin induced uterine contractions by inhibiting COX and therefore reducing PG production?
Indomethacin (NSAID)
What is a natural PGE used to tx hydatidiform mole?
Dinoprostone
What is a synthetic PGE used to DILATE the cervix and can also be used as an abortificant?
Misoprostol
What drugs are natural PGF2A?
Dinoprost and Carboprost
What are PGs responsible for?
hyperalgesia (pain) inflammation fever vomiting diarrhea
What are SE of PGs?
flu-like sxs
What is the difference between PGER and PGFR?
PGER= Gs coupled PGFR= Gq > stimulates IP3
What drug mediates contraction of the uterus and is used to control postpartum bleeding?
Ergonovine-ergometrine
Uterine contractions compress BVs to reduce bleeding
What is used to tx migraine HA?
ergotamine
What drug is a nonselective COX 1/2 inhibitor that decreases PG formation and is used to delay labor short term and is antiinflammatory?
NSAID (indomethacin)
Prevents seizures associated w/ eclampsia and competes w/ Ca to relax SM
Mg Sulfate
What is a tocolytic?
any drugs used to suppress uterine SM> suppress premature labor
Can be used after 20 week to suppress preterm labor but may increase HR, cause pulmonary edema, hyperglycemia nad precipitate MI by increasing O2 demand (by incrased HR)?
B2 agonists (terbutaline)
What is the MOA of terbutaline?
B2 selective agent>
AC>
increased cAMP
What drug inhibits OTR inositol triphosphate activation in order to delay labor and has a rapid onset?
Oxytocin receptor antagonist (atosiban)
Why might atosiban be used over terbutaline?
has fewer maternal SE than B2 agonists BUT it may increase fetal mortality…so maybe not.
From posterior pituitary
Can induce labor
Reduce postpartum bleeding
Release milk from mammary glands
Oxytocin
Induces labor
ripens cervix
PGs (Dinoprostone, Dinoprost, and Misoprostol)
reduces post-partum uterine bleeding (NEVER given to induce labor)
Ergonovine
vasoconstrictor used for headaches
Ergotamine
