Uterine Drugs Flashcards
Oxytocin description
Peptide hormone secreted by the posterior pituitary -> milk ejection
Uterus becomes more sensitive to oxytocin during second half of pregnancy
Oxytocin mechanism
Activates Gq->Increase calcium -> MLCK -> contraction increases PG synthesis which further stimulates contraction of uterus
Oxytocin Indication
**DOC for induction of labor** Augment dysfunctional labor **Limit post partum hemorrhage** Challenge test -> fetal hypoxia -> measure heart rate Induce abortion
Oxytocin Adverse
Rare: fetal distress, placental abruption, uterine rupture
Activate vasopressin receptors -> fluid retention, hyponatremia, seizures and death
Hypotension when given as a bolus
Uterine stimulants
Oxytocin Eronovine Methylergonovine Carboprost Tromethamine Dinoprostone Misoprostol
Ergonovine and Methylergonovine description
Partial alpha agonist and some 5-HT
Sensitivity to ergo alkaloids increases dramatically during pregnancy
Ergonovine and Methylergonovine indication
Second line for post partum hemorrahge when oxytocin is ineffective (or use both)
Found in breast milk
Ergonovine and Methylergonovine Adverse
HTN, HA, seizure, nausea, vomiting, chest pain, leg cramps
*Gangrene in nursing infant
Ergonovine and Methylergonovine contraindications
Angina MI Pregnancy CVA HTN
Carboprost and Tromethamine description
PGF2 alpha analog
Carboprost and Tromethamine indication
Induce abortion in second trimester
Post - partum hemorrhage (3rd line of treatment)
Carboprost and Tromethamine PK
IM
Ergonovine and Methylergonovine PK
IM
Found in breast milk
Oxytocin PK
IV (slow)
IM
Nasal spray
Dinoprostone description
PGE2
Dinoprostone indication
Induce abortion in second trimester
Evacuate uterus after missed abortion
Benign hydatiform mole
Ripen the cervix
Dinoprostone PK
Vaginal insert or suppository
Cervical gel
Misoprostol description
PGE1 analog
*Not FDA approved for OB use (only approved for use with NSAID induced gastric ulcers)
Misoprostol indication
Ripen cervix
Induce labor
Post-partum hemorrhage
Tocolytics (uterine relaxants)
Magnesium sulfate Indometahcin Nifedipine Atosiban Terbutaline (beta 2 agonist)
Magnesium sulfate
Similar efficacy to terbutaline with better tolerance
Uncouples excitation contraction in myometrium (opposes calcium)**
Magnesium sulfate indication
Most popular tocolytic
Magnesium sulfate PK
crosses the placenta
Magnesium sulfate adverse
Respiratory depression
Cardiac arrest
