Indications
Antepartum : Induction of labour for medical reasons, e.g. in cases of post-term gestation, premature rupture of the membranes, pregnancy-induced hypertension (pre-eclampsia); Stimulation of labour in hypotonic uterine inertia; Early stages of pregnancy as adjunctive therapy for the management of incomplete, inevitable, or missed abortion. Postpartum : During caesarean section, but following delivery of the child ; Prevention and treatment of postpartum uterine atony and haemorrhage.
Dosage and Administration
Usage: Intravenous Infusion or Intramuscular Injection.
1. Induction or enhancement of labour: If vaginal prostaglandins have been used, oxytocin should be started at least 6 hours after use of vaginal prostaglandins. Oxytocin should be administered as an intravenous drip infusion or preferably, by means of a variable-speed infusion pump. For drip infusion it is recommended that 5 units of oxytocin be added to 500 ml of a physiological electrolyte solution (such as sodium chloride 0.9%).
2. Caesarean section : The usual dose is 5 units by intravenous infusion over 5 minutes immediately after delivery.
3. Prevention of postpartum uterine haemorrhage: The usual dose is 10 units. Alternatively, 5 units can be given by intravenous infusion over 5 minutes after delivery of the placenta.
4. Treatment of postpartum uterine haemorrhage: The usual dose is 10 units by intramuscular or intravenous injection.
5. Incomplete, inevitable, or missed abortion: The usual dose is 5 units by intravenous infusion.
Precautions & Warning:
1. Oxytocin via intravenous infusion is preferred, as intravenous bolus injection may cause short-lasting hypotension accompanied by flushing and reflex tachycardia.
2. Induction of labour: The induction of labour by oxytocin should be attempted only when strictly indicated for medical reasons. Administration should only be under hospital conditions and qualified medical supervision. Oxytocin should not be infused via the same apparatus as blood or plasma, because it is rapidly inactivated by oxytocin-inactivating enzymes.
3. Use for induction and enhancement of labour Fetal distress and fetal death: Excessive doses of oxytocin can result in uterine overstimulation which may cause fetal distress, asphyxia and death, or may lead to hypertonicity, tetanic contractions or rupture of the uterus.
4. Water intoxication: Features of water intoxication include: - Headache, anorexia, nausea, vomiting and abdominal pain. - Lethargy, drowsiness, unconsciousness and grand –mal type seizures.
Contraindications:
1. Hypersensitivity to the active substance or to any of the excipients.
2. Hypertonic uterine contractions, mechanical obstruction to delivery, fetal distress. Any condition in which, for fetal or maternal reasons, spontaneous labour is inadvisable or vaginal delivery is contra-indicated.
Adverse Reactions:
As there is a wide variation in uterine sensitivity, uterine spasm may be caused in some instances by low doses. When oxytocin is used for the induction or enhancement of labour, excessive doses can result in uterine overstimulation which may cause fetal distress, asphyxia, and death, or may lead to hypertonicity, tetanic contractions, soft tissue damage or rupture of the uterus.
1. Immune system disorders: anaphylactic or anaphylactoid reaction associated with dyspnoea, hypotension or shock.
2. Nervous system disorders: headache.
3. Cardiac disorders: tachycardia, bradycardia; arrhythmia.
4. Gastrointestinal disorders:nausea, vomiting.
5. Vascular disorders: hypotension, haemorrhage, angioedema.
6. Skin : rash
Storage instructions:
Store in a cool and dry place, below 20℃.