Uterine Contractions

Question 1

Misoprostol

Answer 1

Uterine Contractions
Prostaglandin PGE1 agonist
Therapeutic Indications
• Cervical Ripening
• Induction of Labor (IOL)
• Abortifacient
• Post-partum Hemorrhage
• Prevention/treatment
MOA  
• PIP3 agonist, which eventually increases the intracellular calcium, thus inducing uterine contractions. 
Adverse Effects
• *Diarrhea and shivering (short-lived)
• Uterine hyperstimulation
• Uterine rupture w/wo Fetal Heart Rate changes
- Mother and Fetus should be monitored
Contraindications
• Women attempting vaginal birth with prior caesarean section

Question 2

Dinoprostone

Answer 2

Uterine Contractions
Prostaglandin PGE2 agonist
- Two types: Prepidil Gel and Cervidil
• Prepidil = 6 hour duration
- Cervidil = 12 hour duration
• Physicians like to give cervidil first, then if necessary, oxytocin.
Therapeutic Indications
• Cervical Ripening (most common) and IOL
• Cervidil is sustained-release
MOA
• PIP3 agonist, which eventually increases the intracellular calcium, thus inducing uterine contractions.
Adverse Effects
• *Hypertension, Hepatic, renal dysfunction, and Glaucoma
• Uterine hyperstimulation
• Uterine rupture w/wo Fetal Heart Rate changes
- Mother and Fetus should be monitored

Question 3

Carboprost

Answer 3

Uterine Contractions
Prostaglandin PGF2alpha agonist
Therapeutic Indications
• Postpartum hemorrhage (due to uterine atony)
MOA
• PIP3 agonist, which eventually increases the intracellular calcium, thus inducing uterine contractions.
Adverse Effects
• *Nausea, Vomiting, Diarrhea
• Uterine hyperstimulation
- Uterine rupture w/wo Fetal Heart Rate changes
- Mother and Fetus should be monitored

Question 4

Methylergonovine

Answer 4

Uterine Contractions
Ergot Alkaloids
- Produced by claviceps pururea a fungus
Therapeutic Indications
• prevent and treat post-partum hemorrhage, not inducement of labor
Mechanism of Action
• α1-adrenergic, dopaminergic, agonist at serotonin receptors (5-HT1A and 5-HT1D )
- Induces uteronic effect and decreases blood loss
Adverse Effects
• Diarrhea, Nausea, Vomiting
- *fetus: shock, severe HTN, dysrhythmias
Contraindications
• Obstructive vascular disease
• Collagen disease

Question 5

Oxytocin (pitocin)

Answer 5

Uterine Contractions
Therapeutic Indications
• Dilute oxytocin most effective medical means of IOL often used after cervical ripening by Prostaglandins
• Postpartum hemorrhage
MOA
- Acts on oxytocin receptor, which stimulates prostaglandins to be released, which in turn induce more oxytocin (+) Feedback.
Adverse Effects:
• Hyperstimulation of uterine contractions
• Activation of vasopressin receptors
• Excessive fluid retention
• Hyponatremia, heart failure, seizures, or death
Contraindications
• Fetal distress
• Prematurity
• Abnormal fetal presentation