Oxytocin
Drug Related WarningOxytocin
- An individual who is pregnant and does not have a medical reason to induce labor is said to be undergoing elective induction of labor.
- Oxytocin is not recommended for artificial labour induction since insufficient data assesses the benefits versus the risks.
Medicine Type :
Allopathy
Allopathy
Prescription Type:
Prescription Required
Prescription Required
Approval :
DCGI (Drugs Controller General of India)
DCGI (Drugs Controller General of India)
Schedule
Schedule H
Schedule H
Pharmacological Class:
Posterior pituitary hormone, Therapy Class:
Uterine stimulant, Approved Countries
The United States, Canada, the United Kingdom, Australia, Germany, France, Italy, Japan, India, Brazil and Mexico.
Oxytocin is a uterine stimulant belonging to the pharmacological class of Posterior pituitary hormone.
The FDA approves Oxytocin for antepartum (inducing labour in cases of preeclampsia, maternal diabetes, premature rupture of membranes, uterine inertia, and abortions) and postpartum (delivering the placenta, managing haemorrhage).
Following intravenous or intramuscular delivery, Oxytocin is quickly absorbed. It diffuses widely in extracellular fluid, crosses the placenta, and only slightly penetrates breast milk. The kidneys and liver mostly metabolize it. Its primary means of elimination is urine excretion.
The most common side effects of Oxytocin include vomiting, headache, and dizziness.
Oxytocin is available as an injectable solution.
The molecule is available in the United States, Canada, the United Kingdom, Australia, Germany, France, Italy, Japan, India, Brazil and Mexico.
Oxytocin is a uterine stimulant belonging to the pharmacological class of Posterior pituitary hormone.
The hypothalamus produces Oxytocin, stored in the posterior pituitary and released during childbirth to induce uterine contractions. Oxytocin is essential for labour and delivery. The concentration of oxytocin receptors on the myometrium rises during pregnancy and peaks in the early stages of labour. When these receptors are activated, a cascade raises intracellular calcium and intensifies and amplifies uterine contractions. The unique way that oxytocin functions is through positive feedback: applying pressure to the cervix releases Oxytocin, which in turn causes uterine contractions, which remove even more Oxytocin. This cycle of feedback continues until birth. The controlled use of synthetic Oxytocin to induce or intensify uterine contractions during particular antepartum and postpartum periods is made possible by its ability to mimic endogenous effects.
The time required for Oxytocin to show its effects usually begins within 3 to 5 minutes after administration
Oxytocin's effects may last 30 to 60 minutes after administration.
Oxytocin's peak plasma concentration (Cmax) is rapidly achieved within minutes after intravenous administration (Tmax).
Oxytocin is available as an Injectable solution.
Injectable solutions: To be administered by IM and IV infusion.
The physician recommends taking the medication with or without food as directed.
Oxytocin can be used in the following conditions:
- Antepartum
- Postpartum
Antepartum: Oxytocin provides crucial benefits by actively inducing or enhancing uterine contractions for early vaginal delivery, medically indicated labor induction, stimulating labor in uterine inertia cases, and serving as adjunctive therapy for incomplete abortions.
Postpartum: The active administration of synthetic oxytocin in the third stage of labor prevents hemorrhaging, effectively manages immediate post-delivery hemorrhage, and proactively ensures optimal maternal and fetal outcomes.
(1) Antepartum: Oxytocin injection (synthetic) induces or enhances uterine contractions for early vaginal delivery due to fetal or maternal reasons. It's used for
- labor induction in medically indicated situations like Rh problems, maternal diabetes, and preeclampsia, ensuring the best interest of both;
- labor stimulation or reinforcement in selected cases of uterine inertia;
- adjunctive therapy for incomplete or inevitable abortion. Curettage is primary for first-trimester abortion; oxytocin infusion is successful for second-trimester abortion but may need other therapies in some cases.
(2) Postpartum: It is indicated to administer a synthetic oxytocin injection to induce uterine contractions in the third stage of labor and to manage haemorrhaging immediately after delivery.
The dosage of Oxytocin is determined by uterine response. The following dosage information is based on the various regimens and indications in general use.
Induction or Stimulation of Labor
Administer Oxytocin exclusively via intravenous infusion (drip method) for labor induction or stimulation. Precise control of infusion rate using an infusion pump is vital, along with continuous monitoring of contraction strength and fetal heart rate. If contractions become too intense, promptly halt the infusion and initiate a non-oxytocin-containing intravenous solution. Monitor fetal heart rate and uterine activity, discontinue Oxytocin if hyperactivity or fetal distress occurs, and immediately evaluate the mother and fetus. Oxygen should be provided to the mother if needed.
Control of Postpartum Uterine Bleeding
Intravenous Infusion (Drip Method): To manage a postpartum haemorrhage, a nonhydrating diluent (1,000 mL) can be mixed with 10–40 units of Oxytocin and administered at a rate that regulates uterine atony.
Intramuscular Administration: 1 mL (10 units) of Oxytocin can be administered following placenta delivery.
Treatment of Incomplete or Inevitable Abortion
Intravenous infusions should be administered at 20 to 40 drops per minute using 500 mL of physiological saline solution, 5% dextrose in physiological saline solution, or 10 units of Oxytocin.
When solution and container allow, parenteral drug products should be visually inspected for discolouration and particulate matter before administration.
The dosage and duration of treatment should be as per the treating physician's clinical judgment.
Injectable Solution: 10 units/mL
Oxytocin is available as an injectable solution.
Dose Adjustment in Adult Patients:
Postpartum haemorrhage 10-unit IM after placenta delivery
To 1000 mL of nonhydrating IV solution, add 10–40 units, not more than 40 units, and infuse at the required rate to manage uterine atony.
Induction of Labor
0.5–1 mUnit/min IV, titrate 1-2 mUnit/min every 15–60 minutes until a contraction pattern similar to normal labour is achieved (usually 6 mUnits/min); after the desired frequency of contractions is reached, and labor has advanced to a 5–6 cm dilation, the dosage may be decreased.
Incomplete or Inevitable Abortion
10–20 minutes/min; a maximum of 30 units per hour
Avoid grapefruit or grapefruit juice while using Oxytocin to avoid changing its effects. Limit the fluid intake to prevent electrolyte imbalances and water retention caused by antidiuretics. Limit your intake of caffeine and sugary beverages in favour of frequent little snacks. Consume spicy food in moderation to avoid digestive problems. Drink clear liquids to stay hydrated, and choose meals that are simple to digest. Avoid alcohol while giving birth to avoid exacerbating any adverse effects. Use small doses of castor oil to stimulate prostaglandins for cervical ripening and labour onset. When inducing labor, take into account foods with cervical ripening properties, such as dates and raspberry tea leaves.
The dietary restriction should be individualized as per patient requirements.
Oxytocin may be contraindicated in the following conditions:-
- Prominent cephalopelvic disproportion
- Undesirable fetal positions or presentations that cannot be delivered without conversion before delivery, such as transverse lies.
- When a mother or the fetus's benefit-to-risk ratio suggests surgical intervention in an emergency involving pregnancy.
- If delivery is not imminent, but there is fetal distress
- Prolonged use in cases of severe toxemia or uterine inertia
- Patterns in the hypertonic uterus
- Individuals with severe drug hypersensitivity
- When vaginal delivery is not recommended, such as in situations involving cord presentation or prolapse, complete placenta previa, or vasa previa, induction or augmentation of labor.
- Immediately discontinue if uterine hyperactivity arises.
- Trained personnel should administer intravenous preparations.
- Prolonged use may lead to severe water intoxication due to antidiuretic effects.
- Consider restricting fluid intake as a precaution.
- High doses may cause uterine hypertonicity, spasm, rupture, or tetanic contractions.
- Avoid intramuscular administration for labor induction/augmentation.
Alcohol Warning
It is unsafe to consume alcohol.
Breast Feeding Warning
Oxytocin is safe to use during breastfeeding.
Pregnancy Warning
It is generally considered to be safe when used during pregnancy. Animal studies indicate minimal fetal risks; human data is limited.
Food Warning
Avoid grapefruit and alcohol; hydrate and moderate caffeine intake.
The adverse reactions related to Oxytocin can be categorized as
- Common Adverse Effects: Nausea, vomiting, and uterine hyperactivity.
- Less Common Adverse Effects: Headaches, hypertension, and allergic reactions.
- Rare Adverse Effects: Cardiac arrhythmias, water intoxication, and uterine rupture.
The clinically relevant drug interactions of Oxytocin are briefly summarized here.
- Drug-Drug Interactions: Anesthesias (sevoflurane, halothane, cyclopropane, desflurane), prostaglandins, antidiuretic hormone (vasopressin), neurotransmitters (dopamine), anti-sickness medication (ondansetron), sympathomimetic agents (epinephrine), and other medications used to induce labor should be used cautiously when combined with Oxytocin.
- Drug-Food Interactions: Consuming alcohol while taking Oxytocin should be avoided as it may interact and cause unpleasant side effects.
- Drug-Disease Interactions: Patients who have had a cesarean section in the past, have hypertension (high blood pressure), heart problems, cervical cancer, herpes infection, kidney problems, or whose pelvis is too small for a standard delivery should not take Oxytocin.
The common side effects of Oxytocin include: -
Nausea
Vomiting
Headache
Skin rashes
Fast heartbeat
Uterine contractions
- Pregnancy
Pregnancy Category C (FDA): Use caution if the benefits outweigh the risks.
In pregnancy, oxytocin injections are used for inducing labor in patients who have a medical indication to do so; stimulating or reinforcing labor, such as in some instances of uterine inertia; and serving as adjuvant therapy for the management of incomplete or unavoidable abortions; Given the extensive experience with this medication and its chemical and pharmacological characteristics, it is not expected to pose a risk of fetal abnormalities when used as prescribed. There are no known indications for using this medication in the first or second trimester of pregnancy other than in connection with spontaneous or induced abortion.
- Nursing Mothers
It is unknown if this medication is eliminated in human milk; however, since numerous medications are stopped in human milk, caution should be taken when giving Oxytocin to a nursing mother.
The advantages of breastfeeding for development and health should be taken into account, as well as the mother's clinical need for oxytocin injection and any possible risks to the breastfed child from oxytocin injection or an underlying medical condition.
- Pediatric Use
As per the FDA, the safety and efficacy of Oxytocin in pediatric patients have yet to be extensively studied or established.
Dose Adjustment in Kidney Impairment Patients:
Due to its rapid metabolism and excretion, no dose adjustment is required in kidney impairment patients.
Dose Adjustment in Hepatic Impairment Patients:
Oxytocin doesn't have a specific dose adjustment in hepatic impairment due to its rapid metabolism and excretion.
The physician should be vigilant about the knowledge pertaining to the identification and treatment of overdosage of Oxytocin.
Signs and Symptoms
Overdosage of Oxytocin can result in uterine hyperactivity, water retention, tachycardia, hypotension, nausea, vomiting, and cardiac arrhythmias, potentially leading to maternal and fetal distress.
Management
There is no specific antidote or treatment for excessive Oxytocin intake. However, immediate medical attention is essential. Oxytocin should be terminated immediately when an overdose is suspected or if any unusual symptoms occur after intake to prevent further adverse effects.
For symptomatic treatment, manage hypotension with fluid resuscitation and elevate the lower extremities to improve venous return. Address tachycardia and arrhythmias by closely monitoring vital signs and administering medications if necessary. In severe cases where there's a risk of water intoxication or hyponatremia due to excessive fluid retention, consider diuretics to increase urine output and normalize electrolyte levels.
Addressing maternal and fetal status is crucial, closely monitoring uterine contractions and fetal heart rate. If uterine hyperactivity causes fetal distress or there are concerns for maternal health, consider administering a tocolytic agent like terbutaline or nitroglycerin to reduce uterine contractions.
Close vital sign monitoring is crucial, emphasizing timely medical intervention to mitigate potential risks from Oxytocin overdose.
Continuous fetal monitoring and maternal observation post-overdose are essential.
Pharmacodynamics:
It is commonly known that Oxytocin stimulates parturition and lactation. Still, it also has significant physiological effects on metabolic and cardiovascular processes, sexual and maternal behaviour, pair bonding, social cognition, and fear conditioning. Oxytocin is a nonapeptide, pleiotropic hormone.
It's important to consider that oxytocin receptors are not just found in the reproductive system but also in various peripheral tissues and parts of the central nervous system, such as the brain stem and memory region.
Pharmacokinetics:
Absorption
When administered intravenously or intramuscularly, Oxytocin gets rapidly absorbed and distributed throughout the body; it reaches peak plasma levels within minutes of administration.
Distribution
Oxytocin distributes widely within the extracellular fluid upon administration. It can cross the placenta and enter breast milk in minimal quantities.
Vd: 0.3 L/kg
Metabolism
Metabolism primarily occurs in the liver and kidneys. Oxytocinase, predominantly responsible for metabolizing and regulating oxytocin levels during pregnancy, increases its activity as term approaches. The placenta and various organs, including mammary glands and the heart, express oxytocinase, responding to rising oxytocin levels.
Elimination
The drug is excreted primarily through urine, albeit in small amounts and mainly as an unchanged substance. The elimination half-life of Oxytocin is relatively short, lasting between 1 to 6 minutes.
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Published on: 8 Dec 2023 10:26 AM GMT
