Drug Guide

Generic Name

Oxytocin

Brand Names Syntocinon, Pitocin, Oxytocin 5 Usp Units In Dextrose 5%, Oxytocin 20 Usp Units In Dextrose 5%, Oxytocin 10 Usp Units In Dextrose 5%

Classification

Therapeutic: Uterine stimulant, labor inducer, postpartum bleeding control

Pharmacological: Oxytocin receptor agonist

FDA Approved Indications

Induction of labor
Augmentation of labor
Control of postpartum bleeding

Mechanism of Action

Oxytocin acts on specific oxytocin receptors in the uterine myometrium, inducing uterine contractions. It also promotes milk ejection during breastfeeding.

Dosage and Administration

Adult: Administer IV infusion or IM injection; dosing varies based on indication and response. For labor induction, typically start with low doses and titrate upward.

Pediatric: Not commonly used in pediatric patients unless specific indications arise; dosing should be guided by pediatric specialists.

Geriatric: Use with caution; monitor closely due to increased risk of uterine hyperstimulation.

Renal Impairment: Adjustments not well established; use cautiously with close monitoring.

Hepatic Impairment: Use cautiously; hepatic impairment may alter drug metabolism.

Pharmacokinetics

Absorption: Rapid onset when administered IV, slower with IM

Distribution: Widely distributed; crosses placenta

Metabolism: Metabolized in the liver and kidneys

Excretion: Metabolites excreted in urine

Half Life: Approximately 1-6 minutes (IV) and 20-40 minutes (IM)

Contraindications

Fetal distress
Unfavorable fetal position
Women with obstetric emergencies requiring surgical intervention
Uterine scar from previous cesarean or uterine surgery unless otherwise advised

Precautions

Monitor fetal heart rate, uterine contractions, and maternal vital signs regularly. Use cautiously in women with cardiovascular disease, hypertension, or predisposition to uterine rupture.

Adverse Reactions - Common

Uterine hyperstimulation (Common)
Water intoxication (hyponatremia) (Occasional)
Nausea, vomiting (Common)
Hypotension or hypertension (Less common)

Adverse Reactions - Serious

Uterine rupture (Rare)
Fetal distress (Rare)
Seizures due to water intoxication (Rare)

Drug-Drug Interactions

Other uterotonics (e.g., ergometrine)
Mifepristone (antagonist, may reduce efficacy)

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor uterine tone and contractions, fetal heart rate, maternal blood pressure, and water balance.

Diagnoses:

Risk for uterine hyperstimulation
Risk for fetal distress
Potential fluid volume overload

Implementation: Administer as per protocol, titrate carefully, and monitor continuously.

Evaluation: Assess fetal and maternal response, uterine contraction pattern, and water status.

Patient/Family Teaching

Report any abdominal pain, vaginal bleeding, or changes in fetal movement immediately.
Inform about the importance of continuous fetal monitoring during administration.
Discuss potential side effects, including water intoxication and uterine hyperstimulation.

Special Considerations

Black Box Warnings:

Potential for uterine rupture with high doses or in women with previous uterine surgery.
Risk of water intoxication leading to hyponatremia; use caution to prevent excessive water retention.

Genetic Factors: None established specific to genetic factors.

Lab Test Interference: May cause false results in certain blood assays due to water retention.

Overdose Management

Signs/Symptoms: Uterine hyperstimulation, water intoxication symptoms like nausea, headache, confusion, seizures, hypotension.

Treatment: Discontinue oxytocin immediately. Manage water intoxication with fluid restriction and supportive care; treat hyperstimulation with appropriate tocolytics and uterine relaxation agents if needed.

Storage and Handling

Storage: Store at room temperature (15-30°C), protected from light.

Stability: Stable under recommended storage conditions; check specific product stability data.