Oxytocin is indicated in- Induction of labor, stimulation of uterine contractions. Post delivery period, for the prevention or treatment of secondary haemorrhage and adherent placenta. To stimulate lactation, only it advised by the registered Gynaecologist/Physician. ... Read moreOxytocin is indicated in- Induction of labor, stimulation of uterine contractions. Post delivery period, for the prevention or treatment of secondary haemorrhage and adherent placenta. To stimulate lactation, only it advised by the registered Gynaecologist/Physician. Treatment of incomplete abortion to obtain more rapid expulsion in order to prevent secondary hemorrhage.

Drugs acting on the Uterus

Uterine motility depends on the formation of the contractile protein actomyosin under the influence of the Ca2+ dependent phosphorylating enzyme myosin light-chain kinase. Oxytocin promotes contractions by increasing the intracellular Ca2+, which in turn activates myosin's light chain kinase. Oxytocin has specific receptors in the muscle lining of the uterus and the receptor concentration increases greatly during pregnancy, reaching a maximum in early labor at term.

Induction or Stimulation of Labor: The standard solution for infusion of Oxytocin is prepared by adding the contents of one 1ml vial containing 10 units of Oxytocin to 1000 ml of infusion fluids. The combined solution containing 10 mU (1mU=0.001U) of Oxytocin/ml is rotated in the infusion bottle for thorough mixing. The initial dose should be 0.5-1 mU/min (equal to 3-6 ml of the dilute Oxytocin solution per hour). At 30-60 minutes intervals the dose should be gradually increased in increments of 1-2 mU/min until the desired contraction pattern has been established. Once the desired frequency of contractions has been reached and labor has progressed to 5-6 cm dilation, the dose may be reduced by similar increments. At term, higher infusion rates should be given with great care and rates exceeding 9-10 mU/min are rarely required. Before term, when the sensitivity of the uterus is lower because of a lower concentration of Oxytocin receptors, a higher infusion rate may be required. Control of Postpartum Uterine Bleeding: Intravenous Infusion (Drip Method): To control postpartum bleeding, 10 to 40 units of Oxytocin may be added to the bottle, depending on the amount of infusion fluids solution remaining (maximum 40 units to 1000 ml). Adjust infusion rate to sustain uterine contraction and control uterine atony. Intramuscular Administration: 1 mL (10 units) of Oxytocin can be given after the delivery of the placenta. Treatment of Incomplete or Inevitable Abortion: Intravenous infusion of 10 units of Oxytocin added to 500 ml of a 0.9% sodium chloride solution may help the uterus contract after a suction or sharp curettage for an incomplete, inevitable or elective abortion. Subsequent to intra-amniotic injection of hypertonic saline, prostaglandins, urea etc., for mid trimester elective abortion, the injection-to-abortion time may be shortened by infusion of Oxytocin at the rate of 10 to 20 mU (20 to 40 drops) per minute. The total dose should not exceed 30 units in a 12-hour period due to the risk of water intoxication.

Severe hypertension has been reported when Oxytocin was given three to four hours following prophylactic administration of a vasoconstrictor in conjunction with caudal-block anesthesia. Cyclopropane anesthesia may modify Oxytocin’s cardiovascular effects, so as to produce unexpected results such as hypotension. Maternal sinus bradycardia with abnormal atrioventricular rhythms has also been noted when Oxytocin was used concomitantly with cyclopropane anesthesia.

Cephalo-pelvic disproportion. Abnormal position of the child or abnormal position of the skull. Overdistention of the inferior segment of the uterus. Severe toxaemia. Hypertonic uterine dysfunction. Foetal distress, where delivery is not imminent (uterine contractions may increase hypoxia). Cord presentation and prolapse. Total placenta previa. Vasa praevia.

Hypersensitivity to the drug may result in uterine hypertonicity, spasm, titanic contraction or rupture of the uterus.  The possibility of increased blood loss and afbrinigenemia should be kept in mind when administering the drug. Severe water intoxication with convulsions and coma has occurred.  Oxytocin may occasionally cause nausea, vomiting, haemorrhage or cardiac arrhythmias, anaphylactic reaction. Adverse reactions: Exceptionally, symptoms of water intoxication may occur. An increased incidence of icterus neonatorum has been reported after use of oxytocin.

Pregnancy category C. It is not known whether Oxytocin is excreted in human milk

Since uterine sensitivity to oxytocin may vary widely. Oxytocin should be used with care. The smallest effective dose must be determined for each patient and then utilized to initiate labor. Oxytocin should only be used when adequate medical supervision is provided. Fetal heart rate and maternal blood pressure should be determined. Oxytocin should be used with care if scars of the uterus and of the cervix uteri exist.

Excess oxytocin may cause violent uterine contractions leading to fetal bradycardia and arrhythmias, extensive laceration of the soft tissues, uterine rupture and perhaps fetal or maternal death. Treatment consists of immediate discontinuation of the infusion and induction of tocolysis.

Store in between 2 to 8°C, in dark & frost free place. Keep out of the reach of children.

Drugs acting on the Uterus

Uterine motility depends on the formation of the contractile protein actomyosin under the influence of the Ca2+ dependent phosphorylating enzyme myosin light-chain kinase. Oxytocin promotes contractions by increasing the intracellular Ca2+, which in turn activates myosin's light chain kinase. Oxytocin has specific receptors in the muscle lining of the uterus and the receptor concentration increases greatly during pregnancy, reaching a maximum in early labor at term.

Pregnancy category C. It is not known whether Oxytocin is excreted in human milk