What Is Oxytocin and How Does It Work?

Oxytocin is recommended as an aid in the management of the following conditions:

Because of Oxytocin's milk ejecting effect, it will contract smooth muscle cells of the mammary gland for milk letdown if the nipple is in proper physiological state.

Oxytocin is available under the following different brand names: Pitocin.

What Are Dosages of Oxytocin?

Dosages of Oxytocin:

Dosage Forms and Strengths

Injectable solution

  • 10 units/mL

Dosage Considerations – Should be Given as Follows:

Postpartum Hemorrhage

  • 10 unit intramuscularly (IM) after delivery of the placenta
  • Add 10-40 units; not to exceed 40 units; to 1000 mL of non-hydrating intravenous (IV) solution and infuse at the necessary rate to control uterine atony

Labor Induction

  • 0.5-1 mUnit/min IV, titrate 1-2 mUnit/min q15-60min until contraction pattern reached that is similar to normal labor (usually 6 mUnits/min); may decrease dose after the desired frequency of contraction reached and labor has progressed to 5-6 cm dilation

Incomplete or Inevitable Abortion

  • 10-20 mUnit/min; not to exceed 30 units/12 hours


What Are Side Effects Associated with Using Oxytocin?

Common side effects of oxytocin include:

  • Slow heart rate
  • Fast heart rate
  • Premature ventricular complexes and other irregular heartbeats (arrhythmias)
  • Permanent central nervous system (CNS) or brain damage, and death secondary to suffocation
  • Neonatal seizure
  • Neonatal yellowing of skin or eyes (jaundice)
  • Fetal death
  • Low Apgar score (5 minutes)
  • Uteroplacental hypoperfusion and variable deceleration of fetal heart rate
  • Inadequate fetal oxygen levels (hypoxia)
  • Perinatal hepatic necrosis
  • Fetal hypercapnia
  • Severe decreases in maternal systolic and diastolic blood pressure, increases in heart rate, systemic venous return and cardiac output, and arrhythmia

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

What Other Drugs Interact with Oxytocin?

If your doctor has directed you to use this medication, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

  • Severe Interactions of oxytocin include:
    • None
  • Serious Interactions of oxytocin include:
  • Oxytocin has moderate interactions with at least 28 different drugs.
  • Mild Interactions of oxytocin include:
    • None

This information does not contain all possible interactions or adverse effects. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions, concerns, or for more information about this medicine.

What Are Warnings and Precautions for Oxytocin?


  • Elective induction of labor is defined as the initiation of labor in a pregnant individual who has no medical indications for induction
  • Because the available data are inadequate to evaluate the benefits-to-risks considerations, oxytocin is not indicated for elective induction of labor
  • This medication contains oxytocin. Do not take Pitocin if you are allergic to oxytocin or any ingredients contained in this drug
  • Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center immediately.


  • Significant cephalopelvic disproportion
  • Unfavorable fetal positions or presentations, e.g., transverse lies, which are undeliverable without conversion before delivery
  • Obstetric emergencies that favor surgery
  • Fetal distress where delivery is not imminent
  • Where adequate uterine activity fails to achieve satisfactory progress
  • Hyperactive or hypertonic uterus
  • Contraindicated vaginal delivery, e.g., invasive cervical carcinoma, active herpes genitalis, total placenta previa, vasa previa, and cord presentation or prolapse of cord
  • Hypersensitivity
  • Fetal distress, polyhydramnios, partial placenta previa, prematurity, borderline cephalopelvic disproportion, previous major surgery of cervix or uterus (including C-section), over-distension of the uterus, grand multiparity, invasive cervical carcinoma, history of uterine sepsis, or traumatic delivery
  • Hyperstimulation of the uterus, with strong (hypertonic) and/or prolonged (tetanic) contractions, or a resting uterine tone of 15-20 mm H2O between contractions may occur, possibly resulting in uterine rupture, cervical and vaginal lacerations, postpartum hemorrhage, abruptio placentae, impaired uterine blood flow, amniotic fluid embolism, & fetal trauma including intracranial hemorrhage
  • Not indicated for elective labor induction

Effects of Drug Abuse

  • No information available

Short-Term Effects

  • See "What Are Side Effects Associated with Using Oxytocin?"

Long-Term Effects

  • See "What Are Side Effects Associated with Using Oxytocin?"


  • If uterine hyperactivity occurs, discontinue immediately
  • Intravenous preparations should be administered by trained personnel
  • Risk of severe water intoxication on prolonged administration due to its antidiuretic effect
  • Restricting fluid intake may be warranted
  • Uterine hypertonicity, spasm, rupture of the uterus, and tetanic contractions may occur from high doses
  • Intramuscular (IM) not recommended for labor induction/augmentation

Pregnancy and Lactation

  • Do not use oxytocin in pregnancy unless deemed necessary by your obstetrician
  • The risks involved outweigh the potential benefits. Safer alternatives exist
  • Oxytocin may be distributed milk; commencement of nursing should be delayed for at least 1 day when discontinued; use caution
Medscape. Oxytocin.

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