Repro pharm Flashcards
After delivery of a healthy infant, a young woman begins to bleed extensively because her uterus has failed to contract. What can you give her?
Oxytocin
contracts uterine smooth muscle
- also used to control post partum hemorrhage
Gq
Increased by oxytocin
-increase PLC
Myometrial contraction
Gs
increased by beta 2 - relaxes
B2 agonist –> increases Gs –> increases cAMP –> decreases MLCK
*myosin light chain kinase
PGE2, PGF2a, and oxytocin all activate Gq, which increase Ca2+ and causes myometrial contraction, What is their receptors?
PGE2: EP1
PGF2a: FP
Oxytocin: OXT
PGE2: EP1
PGF2a: FP
Oxytocin: OXT
these receptors do what?
activate Gq and cause increase in Ca2+ (thru L type Ca2+ channels) and cause myometrial contraction
PGE and EPI increase Gs and have what effects?
PGE –> Ep2-4 –> Gs –> increase cAMP –> cervic ripening-dilation
EPI –> B2 –> Gs –> increase cAMP –> myometrial relaxation
Cervical dilatation is dependent upon ______
prostaglandins
Oxytocic –>
Tocolytic –>
Oxytocic –> contract
Tocolytic –> relax
Uterin sm also expresses B2-adrenergic receptors that mediate _____
relaxation
Epi –> B2 –> Gs –> Increase cAMP –> myometrial relaxation
HELLP
Hemolysis
Elevated Liver enzymes
Low Platelet count
Leading cause of infant mortality
Preventing preterm labor
Adverse drug rxns of oxytocin
Higher doses –> water intoxication –> coma, convulsions, death
Uterine rupture
Impaired fetal oxygenation
Misoprostol
PGE1 analog
- given orally to induce uterine contractions
CCB
- Nifedipine
- DIltiazem
- Verapamil
all vasodilators
Nifedipine increases HR
Ergot alkaloids
act via a1 and 5HT2 receptors –> direct contraction of vascular and uterine sm
- ONLY used for control of LATE uterine bleeding (if oxytocin doesnt work)
- reduce bleeding by causing sustained contraction of the uterus
A pregnant women presents at term for induction of labor, what to give her?
Admin of PGE2 vaginal gel until cervix has ripened followed in 6 hrs by admin of IC oxytocin thru an infusion pump if active labor has not occured
Wen are tocolytic agents indicated?
when delay in delivery for 48 hours will provide benefit to newborn
- reduce prematurity problems
ie: indomethacin
Indomethacin
tocolytic agent
Prostaglandin synthesis inhibitors (NSAIDS)
Most potent and widely used in suppressing labor in first 24-32 weeks gestation
Choice of inhibition of labor (tocolytic agent) if NSAIDS are contraindicated
(platelet disorders, renal dysfxn, GI ulcer disease, asthma)
Nifedipine CCB
- a vascular sm dilation
- potential concern is that fall in maternal BP may have negative fx on blood flow betwen uterus and placenta
Terbutaline
b2 adrenergic agonist
- tocolytic agent
- inhibition of labor
- less effective if cervix has dilated and membranes have ruptured
- higher relative incidence of maternal side effects
(risk of maternal hyperglycemia, and fetal hypoglycemia)
MgSO4
decreases Ca2+ –> decreases MLCK
- indicated for pre-eclampsia and eclampsia
(tocolytic agent)
drug class that will cause uterine contractions and deliver the products of conception following interruption of an established pregnancy with mifepristone is:
prostaglandin analogs (misoprostol)
*note: prostaglandin analogs have Prost in the name
What drug interacts with nitroglycerin by inhibiting metabolism of cGMP?
sildenafil
Phosphodiesterase inhibitors
-afils
Sildenafil (viagra)
1st line for ED
- blocks cGMP breakdown –> increases cGMP –> enhance vasodilation –> increase blood flow
- enhance fx of nitric oxide
