Oxytocin – Grindeks

/ A.L. Medi-Market LTD,

Induction or enhancement of labour
For labour induction or to increase contractions, Oxytocin may only be administered as an intravenous continuous infusion and never as subcutaneous, intramuscular or intravenous bolus injection.
The initial infusion rate should be set at 1-4 mU/min (2-8 drops/min). It may be gradually increased at intervals not shorter than 20 min, until a contraction pattern similar to that of normal labour is established. In pregnancy near term this can often be achieved with an infusion of less than 10 mU/min (20 drops/min), and the recommended maximum rate is 20 mU/min (40 drops/min).
Caesarean section
Immediately after extraction of the infant, 5 IU can be injected slowly I.V.
Prevention of postpartum uterine haemorrhage
The usual dose is 5 IU slowly I.V. after delivery of the placenta. In women given Oxytocin for induction or enhancement of labour, the infusion should be continued at an increased rate during the third stage of labour and for the next few hours thereafter.
Treatment of postpartum uterine haemorrhage
5-10 IU I.M. or 5 IU slowly I.V., followed in severe cases by intravenous infusion of a solution containing 5-20 IU of oxytocin in 500 ml of a non-hydrating diluent, run at the rate necessary to control uterine atony.
Due to the antidiuretic effect of Oxytocin which suppresses urine excretion Undesirable effects), the following measures should be observed when administering Oxytocin at high doses:
An isotonic sodium chloride solution (not glucose) should be used and the infused volume of fluid must be kept low. At the same time, oral fluid intake should be restricted and the fluid balance monitored. If an electrolyte imbalance is suspected, serum electrolytes must be monitored.
Incomplete, inevitable, or missed abortion
5 IU I.M. or slowly I.V., if necessary followed by intravenous infusion at a rate of 20-40 mU/min or higher.

• Induction of labour for medical reasons;
• Stimulation of labour in hypotonic uterine inertia;
• During Caesarean section following the delivery of the child;
• Prevention and treatment of postpartum uterine atony and haemorrhage.
• In early stages of pregnancy as an adjunctive therapy for the management of incomplete, inevitable or missed abortion

• Hypersensitivity to the active substance or to any of the excipients
• Hypertonic uterine contractions, mechanical obstruction to delivery, foetal distress. Any condition in which, for foetal or maternal reasons, spontaneous labour is inadvisable and/or vaginal delivery is contraindicated.
• Significant cephalopelvic disproportion
• Foetal malpresentation
• Placenta praevia and vasa praevia
• Placental abruption
• Cord presentation or prolapse
• Overdistension or impaired resistance of the uterus to rupture as in multiple pregnancy
• Polyhydramnios
• Grand multiparity
• In the presence of a uterine scar resulting from major surgery including classical Caesarean section.
Oxytocin should not be used for prolonged periods in patients with oxytocin-resistant uterine inertia, severe pre eclamptic toxaemia or severe cardiovascular disorders.
Oxytocin must not be administered within 6 hours after vaginal prostaglandins have been given.

Oxytocin must only be administered as an I.V. infusion and never by I.V. bolus injection as it may cause an acute short-lasting hypotension accompanied with flushing and reflex tachycardia.
Cardiovascular disorders
Oxytocin should be used with caution in patients who have a pre-disposition to myocardial ischaemia due to pre-existing cardiovascular disease (such as hypertrophic cardiomyopathy, valvular heart disease and/or ischaemic heart disease including coronary artery vasospasm), to avoid significant changes in blood pressure and heart rate in these patients.
QT syndrome
Oxytocin be given with caution to patients with known ‘long QT syndrome’ or related symptoms and to patients taking drugs that are known to prolong the QTc interval.
Foetal distress and foetal death: Administration of oxytocin at excessive doses results in uterine overstimulation, which may cause foetal distress, asphyxia and death, or may lead to hypertonicity, tetanic contractions or rupture of the uterus. Careful monitoring of foetal heart rate and uterine motility (frequency, strength, and duration of contractions) is essential, so that the dosage may be adjusted to individual response.
Particular caution is required in the presence of borderline cephalopelvic disproportion, secondary uterine inertia, mild or moderate degrees of pregnancy-induced hypertension or cardiac disease, and in patients above 35 years of age or with a history of lower- uterine-segment Caesarean section.
Disseminated intravascular coagulation: In rare circumstances, the pharmacological induction of labour using uterotonic agents, including oxytocin, increases the risk of postpartum disseminated intravascular coagulation (DIC). The pharmacological induction itself and not a particular agent is linked to such risk. This risk is increased in particular if the woman has additional risk factors for DIC such as being 35 years of age or over, complications during pregnancy and gestational age more than 40 weeks. In these women, oxytocin or any other alternative drug should be used with care, and the practitioner should be alerted by signs of DIC.
Intrauterine death
In the case of foetal death in utero, and/or in the presence of meconium-stained amniotic fluid, tumultuous labour must be avoided, as it may cause amniotic fluid embolism.
Water intoxication
Because oxytocin possesses slight antidiuretic activity, its prolonged I.V. administration at high doses in conjunction with large volumes of fluid, as may be the case in the treatment of inevitable or missed abortion or in the management of postpartum haemorrhage, may cause water intoxication associated with hyponatraemia. The combined antidiuretic effect of oxytocin and the I.V. fluid administration may cause fluid overload leading to a haemodynamic form of acute pulmonary oedema without hyponatraemia. To avoid these rare complications, the following precautions must be observed whenever high doses of oxytocin are administered over a long time: an electrolyte-containing diluent must be used (not dextrose); the volume of infused fluid should be kept low (by infusing oxytocin at a higher concentration than recommended for the induction or enhancement of labour at term); fluid intake by mouth must be restricted; a fluid balance chart should be kept, and serum electrolytes should be measured when electrolyte imbalance is suspected.
Renal impairment
Caution should be exercised in patients with severe renal impairment because of possible water retention and possible accumulation of oxytocin.
Anaphylaxis in women with latex allergy
There have been reports of anaphylaxis following administration of oxytocin in women with a known latex allergy. Due to the existing structural homology between oxytocin and latex, latex allergy/intolerance may be important predisposing risk factor of anaphylaxis following oxytocin administration.

Common: Headache, Tachycardia, bradycardia, Nausea, vomiting.
See prescribing information for full details.

Prostaglandins and their analogues
Prostaglandins and their analogues facilitate contraction of the myometrium; hence oxytocin can potentiate the uterine action of prostaglandins and analogues and vice versa.
Drugs prolonging the QT interval
Oxytocin should be considered as potentially arrhythmogenic, particularly in patients with other risk factors for torsades de pointes such as drugs which prolong the QT interval or in patients with history of long QT syndrome.
Interactions to be considered
Inhalation anaesthetics: Inhalation anaesthetics (e.g., cyclopropane, halothane, sevoflurane, desflurane) have a relaxing effect on the uterus and produce a notable inhibition of uterine tone and thereby may diminish the uterotonic effect of oxytocin. Their concurrent use with oxytocin has also been reported to cause cardiac rhythm disturbances.
Vasoconstrictors/Sympathomimetics: Oxytocin may enhance the vasopressor effects of vasoconstrictors and sympathomimetics, even those contained in local anaesthetics.
Caudal anaesthetics: When given during or after caudal block anaesthesia, oxytocin may potentiate the pressor effect of sympathomimetic vasoconstrictor agents.

Pregnancy: Based on the wide experience with this drug and its chemical structure and pharmacological properties, it is not expected to present a risk of fetal abnormalities when used as indicated.
Lactation: Oxytocin may be found in small quantities in mother’s breast milk. However, oxytocin is not expected to cause harmful effects in the newborn because it passes into the alimentary tract where it undergoes rapid inactivation.