Oxytocin Injection(5IU/10IU)

1.Mechanism of action:

Binds to oxytocin receptors on uterine smooth muscle, stimulates uterine contraction, increases uterine muscle tension and contraction frequency, the contraction effect is dose-dependent; small dose induces rhythmic uterine contraction similar to labor, large dose causes tonic contraction of uterus; also promotes lactation by contracting mammary gland myoepithelial cells to discharge milk, has weak antidiuretic and vasopressor effects.

1. Usage and dosage: Intramuscular injection or intravenous drip (slow and controlled infusion is recommended).

   1. Induction/Augmentation of labor: Intravenous drip, start with 2.5 Units diluted in 500ml normal saline, adjust drip rate according to uterine contraction (8~10 contractions per 10 minutes), maximum dose ≤20mU/min.
   2. Postpartum hemorrhage: Intramuscular injection 10 Units once after delivery of placenta; severe hemorrhage: intravenous drip 20 Units diluted in 500ml infusion solution.
   3. Uterine involution: Intramuscular injection 5~10 Units once, 1~2 times a day for 2~3 days.

2.Indications:

Induction and augmentation of labor in term pregnancy with medical indication; prevention and treatment of postpartum uterine atony and postpartum hemorrhage; promotion of uterine involution after delivery and abortion; also used for milk ejection aid in lactatin

3.Contraindications:

Contraindicated in patients allergic to this product and any excipients of the preparation; contraindicated in cephalopelvic disproportion, fetal malposition (transverse lie, breech presentation with complications), uterine scar, threatened uterine rupture; contraindicated in severe pregnancy-induced hypertension, eclampsia and pre-eclampsia; contraindicated in fetal distress and placental abruption; contraindicated in hypertonic uterine contraction.

4.Cautious population:

Use with extreme caution in patients with heart disease, hypertension, renal insufficiency and asthma; use with caution in multipara and uterine overdistension (polyhydramnios, multiple pregnancy); use with caution in patients with diabetes and hypothyroidism; monitor fetal heart rate and uterine contraction closely during medication; avoid rapid intravenous injection to prevent hypotension and arrhythmia.

5.Adverse reactions:

Uterine adverse reactions: excessive uterine contraction (hypertonia, tetanic contraction), uterine rupture, placental abruption (caused by overdose or rapid infusion).

Fetal adverse reactions: fetal distress, bradycardia, hypoxia and even death (due to excessive uterine contraction).

Maternal systemic reactions: nausea, vomiting, palpitations, headache, dizziness and flushing; rare hypotension, arrhythmia, water intoxication (antidiuretic effect) and allergic reactions (rash, urticaria); local pain at intramuscular injection site is mild and transient.