Oxytocin

Pitocin is the brand name of the hormone oxytocin, which stimulates contractions in the uterus.

Oxytocin is sometimes called the “love hormone” because your body releases it at high concentrations during positive social interactions (such as falling in love) or when giving birth.

The drug is used to start or speed up labor contractions during childbirth and control bleeding afterward.

Pitocin may also be used in women who experience an incomplete or inevitable abortion.

The medicine works by increasing the concentration of calcium inside muscle cells. It’s typically injected into a large muscle or given intravenously.

An oxytocin nasal spray is currently under clinical investigation for treating lactation deficiency in nursing moms, autism, and schizophrenia.

Some research has shown that giving oxytocin to women in labor may increase the chance that her baby will have a low APGAR score (a test to check a newborn's condition) and be more likely to be admitted to the neonatal intensive care unit (NICU).

However, other studies have shown the drug doesn’t harm babies and may shorten labor time by nearly two hours.

Pitocin was approved by the Food and Drug Administration (FDA) in 1980.

Pitocin Warnings

Before receiving Pitocin, you should tell your doctor if you are allergic to any medicines or if you have or have ever had:

• A premature delivery
• High blood pressure
• A heart rhythm disorder
• Cervical cancer
• Diabetes
• Genital herpes
• Previous surgery on your cervix or uterus, including a C-section delivery
• A prolapsed uterus
• Placenta previa (the placenta is in the lower part of the uterus and blocking all of the opening of the birth canal or a part of it)
• Any abnormal position of the fetus, such as breech position, or umbilical cord
• More than five pregnancies
• A difficult labor because of a small pelvis

You should also tell your doctor if you have been pregnant for less than 37 weeks.

Pregnancy and Pitocin

This medicine should not be used during pregnancy, except for inducing labor or abortion.

Pitocin may be passed into human breast milk. You should talk to your doctor about breastfeeding while taking this drug.

Pitocin in Men

Some research suggests that Pitocin may promote bonding in men.

Dads who took a dose of Pitocin via a nasal spray played more closely with their babies in one study.

Another showed that the hormone may help men stay in monogamous relationships by helping them view their partners as more attractive than strangers.

More research needs to be conducted to confirm the drug's effect on men.

Oxytocic; indirectly stimulates contraction of uterine smooth muscle; elicits all the responses of endogenous oxytocin.a

Elective induction of labor (i.e., no medical indication for induction) merely for clinician or patient convenience is not a valid indication for oxytocin use. a

IV infusion of dilute solutions is the method of choice for inducing labor at term and stimulating uterine contractions during the first and second stages of labor.a

Labor Induction

Use for labor induction is indicated in term or near-term pregnancies associated with hypertension (e.g., preeclampsia, eclampsia, cardiovascular-renal disease), erythroblastosis fetalis, maternal or gestational diabetes mellitus, antepartum bleeding, premature placenta rupture (abruptio placentae) chorioamnionitis, or premature rupture of the membranes in which spontaneous labor does not ensue.a c

Routine induction of labor with oxytocin may be indicated in prolonged pregnancies (greater than 42 weeks’ gestation).a c

Eclampsia: if delivery is not imminent within 12 hours following an initial oxytocin infusion, consider cesarean section rather than continued oxytocin administration.a

Induction of labor also may be indicated in cases of uterine fetal death (demise), fetal compromise (e.g., fetal growth retardation, isoimmunization), or static or decreasing maternal weight.a However, may be relatively ineffective in cases of missed abortion, intrauterine fetal death in late pregnancy, benign hydatidiform mole, or fetuses with anencephaly or erythroblastosis fetalis with hydrops or other congenital abnormalities incompatible with life; some clinicians recommend intravaginal dinoprostone.a

Induction of labor also may be indicated because of maternal medical conditions (e.g., diabetes mellitus, renal failure, COPD, chronic hypertension).c

Carefully evaluate pelvic adequacy and other maternal and fetal conditions (including fetal lung maturity) whenever labor induction is considered.a

If labor induction is indicated and cervical status is unfavorable, an agent for cervical ripening (e.g., dinoprostone) may be administered initially.c

Do not use to induce labor when the benefit-to-risk ratio for the mother or child favors surgical intervention.a

Labor induction and/or oxytocin may be contraindicated in certain fetal and/or maternal conditions.a (See Contraindications)

Augmentation of Labor

May use during the first and second stages of labor to augment contractions if labor is prolonged or if dysfunctional uterine inertia (oxytocin usually not to exceed 6–8 hours) occurs.a

Not recommended when labor is progressing normally during the first and second stages or when hypertonic patterns of labor occur, especially since drug response may be accentuated during the second stage of labor.a

Do not use to augment labor when vaginal delivery is contraindicated (e.g., total placenta previa).a

Postpartum Abbreviation of Third Stage of Labor

Has been used to shorten the third stage of labor immediately following delivery of the infant (when the absence of additional fetuses is established); oxytocin usually is recommended if an oxytocic is used for this purpose.a

Oxytocics may inhibit rather than assist in placenta expulsion, and increase the risk of hemorrhage and infection.a

Postpartum Control of Uterine Bleeding

Routinely used postpartum or following cesarean section to stimulate immediate uterine contractions and control uterine bleeding.a

Postpartum hemorrhage and uterine atony: Ergonovine or methylergonovine usually preferred (due to more sustained contractions and higher uterine tonus) unless an immediate contractile response is desired.a

IV oxytocin followed by an IM amine ergot alkaloid may be preferred.a

Termination of Pregnancy

Has been used to shorten the induction-to-abortion time following prostaglandin or hypertonic abortifacients for induction of second trimester abortions; to induce abortion after failure to respond to the abortifacient; or to induce abortion after membrane rupture.a

Has been used as an adjunct in incomplete abortion (when placenta fails to abort spontaneously within 1 hour after fetal abortion), but may hinder rather than assist in placental expulsion.a

Usually, do not administer until the abortifacient oxytocic effect has subsided, and carefully monitor; concurrent use of oxytocin with abortifacients may produce intense uterine contractions that increase risk of uterine rupture or cervical laceration.a

Evaluation of Fetal Respiratory Capability†

Successfully used to evaluate the adequacy of fetal respiratory capabilities in high-risk pregnancies of >31 weeks gestation.a

Transiently impedes uterine blood flow by inducing uterine contractions.a

Positive response (late deceleration in fetal heart rate indicating chronic hypoxia) may occur if placental reserve is low.a

Positive response may be fetal distress and may be indication for pregnancy termination, especially if a lecithin-sphingomyelin ratio >1.5 can be demonstrated.a

Negative response (fetal heart rate unchanged) indicates adequate placental support is probably available.a

Contraindications

• Substantial cephalopelvic disproportion.a b

• Unfavorable fetal position or presentation (e.g., transverse lies) undeliverable without conversion before delivery.a b c

• Obstetric emergencies where maternal or fetal risk-to benefit ratio favors surgery.a b

• Fetal distress when delivery is not imminent.a b

• Umbilical cord prolapse.c

• Uterine activity fails to progress adequately.a b

• Hyperactive or hypertonic uterus.a b

• Vaginal delivery is contraindicated (e.g., invasive cervical carcinoma, active genital herpes infection, total placenta previa, vasa previa, cord presentation or prolapse).a b c

• Uterine or cervical scarring from previous cesarean section or major cervical or uterine (e.g., transfundal) surgery.a b c

• Unengaged fetal head.a b c

• History of hypersensitivity to oxytocin or any ingredient in the formulation.a b

Warnings/Precautions

Warnings

Administer by qualified professional personnel in a hospital where intensive care and surgical facilities are immediately available.a b

Not contraindicated but require special attention for oxytocic therapy in labor induction:

• ≥1 previous low-transverse cesarian deliveriesc

• breech presentationc

• maternal heart diseasec

• multifetal pregnancyc

• polyhydramniosc

• presenting part above the pelvic inletc

• severe hypertensionc

• abnormal fetal heart rate patterns not necessitating emergent deliveryb

Sensitivity Reactions

Anaphylactic and other allergic reactions; rarely fatal.a

Major Toxicities

Dose-related, severe water intoxication (due to oxytocin’s antidiuretic effect) with seizures, coma, and death following prolonged IV infusion of oxytocin with an excessive volume of fluid.a Neonatal seizures also reported.a c Usually, only after prolonged administration of ≥40 milliunits/minute.b c

Consider potential for water intoxication, particularly when administered by IV infusion and patient is receiving oral fluids.a b

Restrict fluid intake, avoid administration of low-sodium infusion fluids and high oxytocin doses for prolonged periods, and monitor fluid intake and output during administration.a

General Precautions

Qualified professional personnel with thorough knowledge and capability to identify complications of oxytocin should observe patient continuously, and a clinician qualified to manage complications should be immediately available.a b c

Continuously monitor uterine contractions, fetal and maternal heart rate, maternal blood pressure, and, if possible, intrauterine pressure to avoid complications.a c

Carefully control delivery to minimize risk of increased postpartum bleeding (may be related to oxytocin-induced thrombocytopenia, afibrinogenemia, and hypoprothrombinemia).a

Electronic monitoring of the fetus is the best method for early detection of overdosage, but accurate measurement of intrauterine pressure during contractions requires intrauterine pressure recording.a

Determination of fetal heart rate via a fetal scalp electrode is more dependable than via external monitoring.a b

Inappropriate administration (e.g., excessive dosage) or with abortifacients or to sensitive patients may cause hyperstimulation of the uterus hazardous to mother and fetus.a c

Strong (hypertonic) and/or prolonged (tetanic) contractions, or a resting uterine tone of 15–20 mm H2O between contractions may result.a

Uterine rupture, cervical and vaginal lacerations, postpartum hemorrhage, abruptio placentae, impaired uterine blood flow, amniotic fluid embolism, and fetal trauma including intracranial hemorrhage may occur.a c

Discontinue immediately if uterine hyperactivity occurs; oxytocin-induced stimulation of uterine contractions usually decreases soon after discontinuance of the drug.a

Do not administer oxytocin when pregnancy is complicated by fetal distress, hydramnios, partial placenta previa, prematurity, borderline cephalopelvic disproportion, predisposition for uterine rupture (e.g., previous major surgery of the cervix or uterus including cesarean section, overdistension of the uterus, grand multiparity, history of uterine sepsis or traumatic delivery), except in unusual circumstances requiring the clinician’s judgment.a b

Maternal death from hypertensive episodes and subarachnoid hemorhage has resulted from injudicious use of oxytocin; also, rupture of the uterus, and fetal deaths due to various causes have been associated with oxytocic drug use for labor induction or augmentation in first and second labor stages.a b

Carefully select patient; evaluate pelvic adequacy, and both maternal and fetal condition before oxytocin use.b Consider that hypertonic contractions may occur when uterus is hypersensitive to oxytocin, even when properly administered.b

Do not administer for prolonged periods in severe toxemia.a

In patients with valvular heart disease and those receiving spinal and epidural anesthesia, administration of large dosages may be particularly hazardous; severe decreases in maternal systolic and diastolic blood pressure, increases in heart rate, systemic venous return and cardiac output, and arrhythmia may occur.a

Specific Populations

Manufacturers state oxytocin is not indicated for use during the first or second trimester of pregnancy other than in relation to spontaneous or induced abortion.201 202 203

Based on experience, chemical and pharmacologic properties, not expected to cause fetal abnormalities when used as indicated.201 202 203

May cause nonteratogenic fetal adverse effects.201 202 203

May be distributed into milk.202 Caution.

Common Adverse Effects

Adverse effects usually are dose related.c

Uterine hyperstimulation and subsequent fetal heart rate deceleration most common. (See Uterine Hyperactivity under General Precautions.)

Maternal nausea, vomiting, sinus bradycardia, premature ventricular complexes; probably related to labor and not the drug.a

Neonatal hyperbilirubinemia, jaundice, retinal hemorrhage, low Apgar scores at 5 minutes.a

Specific Drugs

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
• Signs of high blood pressure like very bad headache or dizziness, passing out, or change in eyesight.
• Bleeding a lot (soaking 1 pad per hour).
• Slow heartbeat.
• A heartbeat that does not feel normal.
• Trouble passing urine.
• Very bad belly pain.
• Seizures.
• Weakness on 1 side of the body, trouble speaking or thinking, change in balance, drooping on one side of the face, or blurred eyesight.

• If you need to store this medicine at home, talk with your doctor, nurse, or pharmacist about how to store it.

Antepartum: Induction of labor in patients with a medical indication (eg, Rh problems, maternal diabetes, preeclampsia, at or near term); stimulation or reinforcement of labor (as in selected cases of uterine inertia); adjunctive therapy in management of incomplete or inevitable abortion

Postpartum: To produce uterine contractions during the third stage of labor and to control postpartum bleeding or hemorrhage.

Note: IV administration requires the use of an infusion pump.

Induction or stimulation of labor: IV: Initial: 0.5 to 1 milliunits/minute; gradually increase dose in increments of 1 to 2 milliunits/minute every 30 to 60 minutes until desired contraction pattern is established; dose may be decreased by similar increments after desired frequency of contractions is reached and labor has progressed to 5 to 6 cm dilation. Infusion rates up to 6 milliunits/minute provide oxytocin levels similar to those with spontaneous labor; rates >9 to 10 milliunits/minute are rarely required. Higher dose regimens (eg, initial dose 2 to 6 milliunits/minute) with larger incremental dose increases (eg, 1 to 6 milliunits/minute) have also been proposed; decrease or discontinue dose for abnormal or excessive uterine contractions (ACOG, 2009).

Note: Discontinue the oxytocin infusion immediately in the event of uterine hyperactivity and/or fetal distress. If uterine contractions become too powerful, the infusion can be stopped abruptly.

Postpartum uterine bleeding:

IM: 10 units after delivery of the placenta

IV: 10 to 40 units added to a running infusion solution depending on amount of infusion fluid remaining (maximum: 40 units in 1,000 mL of IV fluid); adjust infusion rate to sustain uterine contraction and control uterine atony

Adjunctive treatment of abortion: IV:

Incomplete, inevitable, or elective abortion: 10 units as an IV infusion after suction or a sharp curettage (used to help contract the uterus)

Midtrimester elective abortion: 10 to 20 milliunits/minute; maximum total dose: 30 units/12 hours (may decrease injection to abortion time)

There are no dosage adjustments provided in the manufacturer’s labeling.

IV:

Induction or stimulation of labor: Add oxytocin 10 units to NS or LR 1,000 mL to yield a solution containing oxytocin 10 milliunits/mL. Rotate solution to mix.

Postpartum uterine bleeding: Add oxytocin 10 to 40 units to running IV infusion; maximum: 40 units to 1,000 mL.

Adjunctive management of abortion: Add oxytocin 10 units to 500 mL of a physiologic saline solution or D5W.

Frequency not defined.

Cardiovascular: Cardiac arrhythmia (including premature ventricular contraction), hypertension, subarachnoid hemorrhage

Central nervous system: Hypertonia (uterine)

Endocrine & metabolic: Water intoxication (severe water intoxication with seizure and coma is associated with a slow oxytocin infusion over 24 hours)

Gastrointestinal: Nausea, vomiting

Genitourinary: Postpartum hemorrhage, tetanic uterine contractions, uterine rupture, uterine spasm

Hematologic & oncologic: Pelvic hematoma

Hypersensitivity: Anaphylaxis

Concerns related to adverse effects:

• Antidiuretic effect: May produce intrinsic antidiuretic effect (ie, water intoxication). Severe water intoxication with convulsions, coma, and death may occur, particularly with large doses (40 to 50 milliunits/minute) or when given as a slow infusion over 24 hours and if the patient is receiving fluids by mouth.

• Maternal deaths: Maternal deaths caused by hypertensive episodes, subarachnoid hemorrhage, or rupture of the uterus and fetal deaths have occurred with oxytocic medications when used for induction of labor or for augmentation in the first and second stages of labor.

• Uterine effects: High doses or hypersensitivity to oxytocin may cause uterine hypertonicity, spasm, tetanic contraction, or rupture of the uterus.

Other warnings/precautions:

• Appropriate use: [U.S. Boxed Warning]: To be used for medical rather than elective induction of labor. Oxytocin is used to initiate or improve uterine contractions in order to achieve a vaginal delivery; it should only be used when medically needed for fetal or maternal reasons. Medical indications for labor induction may include Rh problems, maternal diabetes, preeclampsia at or near term, when delivery is in the best interest of mother or fetus, or premature rupture of membranes when delivery is indicated. Use is generally not recommended in the following conditions: Fetal distress, hydramnios, partial placenta previa, prematurity, borderline cephalopelvic disproportion, or conditions where there is a predisposition for uterine rupture (eg, previous major surgery on cervix or uterus, cesarean section, overdistention of the uterus, grand multiparity, past history of uterine sepsis or traumatic delivery).

• Trained personnel: Intravenous preparations should be administered by adequately trained individuals familiar with its use and able to identify complications; continuous observation is necessary for all patients.

[U.S. Boxed Warning]: To be used for medical rather than elective induction of labor. Animal reproduction studies have not been conducted. When used as indicated, teratogenic effects would not be expected. Nonteratogenic adverse reactions are reported in the neonate as well as the mother.

Applies to oxytocin: solution

Along with its needed effects, oxytocin may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking oxytocin:

• Confusion
• convulsions (seizures)
• difficulty in breathing
• dizziness
• fast or irregular heartbeat
• headache (continuing or severe)
• hives
• pelvic or abdominal pain (severe)
• skin rash or itching
• vaginal bleeding (increased or continuing)
• weakness
• weight gain (rapid)

• Abdominal pain or cramping
• blood clotting problem that causes prolonged bleeding
• chest pain or discomfort
• cough
• difficulty swallowing
• extra heartbeats
• fainting
• lightheadedness
• pounding or rapid pulse
• puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
• severe bleeding after giving birth
• shortness of breath
• tightness in the chest
• unusual tiredness or weakness
• wheezing

Get emergency help immediately if any of the following symptoms of overdose occur while taking oxytocin:

• Restlessness
• shakiness
• sleepiness
• slow to respond
• slurred speech
• unconsciousness

Some side effects of oxytocin may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

• Nausea
• vomiting

Data not available