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ALERT: U.S. Boxed Warning

The FDA-approved labeling includes a boxed warning. See Warnings/Precautions section for a concise summary of this information. For verbatim wording of the boxed warning, consult the product labeling or www.fda.gov.

Pronunciation

(oks i TOE sin)

Generic Available (U.S.)

Yes

Index Terms

• Pit

Brand Names: U.S.

• Pitocin®

Brand Names: Canada

• Oxytocin for injection

Pharmacologic Category

• Oxytocic Agent

Use: Labeled Indications

Induction of labor in patients with a medical indication; stimulation or reinforcement of labor; adjunctive therapy in management of abortion; to produce uterine contractions during the third stage of labor; control of postpartum bleeding

Pregnancy Risk Factor

C (manufacturer specific)

Pregnancy Considerations

[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.

Lactation

Excretion in breast milk unknown/use caution

Breast-Feeding Considerations

Endogenous levels of oxytocin naturally increase during breast-feeding.

Contraindications

Hypersensitivity to oxytocin or any component of the formulation; significant cephalopelvic disproportion; unfavorable fetal positions; fetal distress when delivery is not imminent; hypertonic or hyperactive uterus; contraindicated vaginal delivery (invasive cervical cancer, active genital herpes, prolapse of the cord, cord presentation, total placenta previa, or vasa previa); obstetrical emergencies where surgical intervention is favored; where adequate uterine activity fails to achieve satisfactory progress

Warnings/Precautions

Boxed warnings:

• Appropriate use: See “Other warnings/precautions” below.

Special handling:

• Hazardous agent: Use appropriate precautions for handling and disposal.

Concerns related to adverse effects:

• Antidiuretic effect: May produce antidiuretic effect (ie, water intoxication). Severe water intoxication with convulsions, coma, and death is associated with a slow oxytocin infusion over 24 hours.

• 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. 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.

• Trained personnel: Intravenous preparations should be administered by adequately trained individuals familiar with its use and able to identify complications.

Adverse Reactions

Frequency not defined.

Fetus or neonate:

Cardiovascular: Arrhythmias (including premature ventricular contractions), bradycardia

Central nervous system: Brain or CNS damage (permanent), neonatal seizure

Hepatic: Neonatal jaundice

Ocular: Neonatal retinal hemorrhage

Miscellaneous: Fetal death, low Apgar score (5 minute)

Mother:

Cardiovascular: Arrhythmias (including premature ventricular contractions), hypertensive episodes

Gastrointestinal: Nausea, vomiting

Genitourinary: Pelvic hematoma, postpartum hemorrhage, uterine hypertonicity, tetanic contraction of the uterus, uterine rupture, uterine spasm

Hematologic: Afibrinogenemia (fatal)

Miscellaneous: Anaphylactic reaction, subarachnoid hemorrhage; severe water intoxication with convulsions, coma, and death is associated with a slow oxytocin infusion over 24 hours

Metabolism/Transport Effects

None known.

Drug Interactions

Dinoprostone: May enhance the therapeutic effect of Oxytocin. Risk D: Consider therapy modification

Misoprostol: May enhance the therapeutic effect of Oxytocin. Risk D: Consider therapy modification

Storage

Store at 20°C to 25°C (68°F to 77°F); excursions permitted to 15°C to 30°C (59°F to 86°F); do not freeze.

Reconstitution

I.V. :

Induction or stimulation of labor: Add oxytocin 10 units to NS or LR 1000 mL to yield a solution containing oxytocin 10 milliunits/mL. Rotate solution to mix.

Postpartum uterine bleeding: Add oxytocin 10-40 units to running I.V. infusion; maximum: 40 units/1000 mL.

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

Compatibility

Stable in D₅LR, D₅1/4NS, D₅1/2NS, D₅NS, D₅W, D₁₀W, LR, 1/2NS, NS.

Y-site administration: Compatible: Amikacin, ampicillin, cefazolin, cefotaxime, cefoxitin, clindamycin, doxycycline, erythromycin lactobionate, gentamicin, heparin, hydrocortisone sodium succinate, insulin (regular), meperidine, metronidazole, minocycline, morphine, nafcillin, oxacillin, piperacillin, potassium chloride, tobramycin, trimethoprim/sulfamethoxazole, vancomycin, vitamin B complex with C, warfarin, zidovudine. Incompatible: Pantoprazole.

Compatibility in syringe: Incompatible: Dimenhydrinate, hydrocortisone sodium succinate, pantoprazole.

Mechanism of Action

Oxytocin stimulates uterine contraction by activating G-protein-coupled receptors that trigger increases in intracellular calcium levels in uterine myofibrils. Oxytocin also increases local prostaglandin production, further stimulating uterine contraction.

Pharmacodynamics/Kinetics

Onset of action: Uterine contractions: I.M.: 3-5 minutes; I.V.: ~1 minute

Duration: I.M.: 2-3 hour; I.V.: 1 hour

Metabolism: Rapidly hepatic and via plasma (by oxytocinase) and to a smaller degree the mammary gland

Half-life elimination: 1-6 minutes; decreased in late pregnancy and during lactation

Excretion: Urine

Dosage

I.V. administration requires the use of an infusion pump. Adults:

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

Postpartum bleeding:

I.M.: Total dose of 10 units after delivery of the placenta

I.V.: 10-40 units by I.V. infusion in 1000 mL of intravenous fluid at a rate sufficient to control uterine atony

Adjunctive treatment of abortion: I.V.: 10-20 milliunits/minute; maximum total dose: 30 units/12 hours

Administration: I.V.

An infusion pump is required for administration.

Monitoring Parameters

Fluid intake and output during administration, uterine activity, blood pressure; fetal monitoring

Dental Health: Effects on Dental Treatment

No significant effects or complications reported

Dental Health: Vasoconstrictor/Local Anesthetic Precautions

No information available to require special precautions

Mental Health: Effects on Mental Status

None reported

Mental Health: Effects on Psychiatric Treatment

None reported

Nursing: Physical Assessment/Monitoring

Monitor blood pressure, fluid intake and output, and labor closely if using oxytocin for induction; fetal monitoring is strongly recommended.

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Injection, solution: 10 units/mL (1 mL, 10 mL, 30 mL)

Pitocin®: 10 units/mL (1 mL, 10 mL) [contains chlorobutanol]

References

ACOG Committee on Practice Bulletins - Obstetrics, "ACOG Practice Bulletin No.107: Induction of Labor,"Obstet Gynecol, 2009, 114(2 Pt 1):386-97.

Rajan PV and Wing DA, "Postpartum Hemorrhage: Evidence-Based Medical Interventions for Prevention and Treatment," Clin Obstet Gynecol, 2010 53(1):165-81.

Wei SQ, Luo ZC, Qi HP, et al, "High-Dose vs Low-Dose Oxytocin for Labor Augmentation: A Systematic Review," Am J Obstet Gynecol, 2010, 203(4):296-304.

International Brand Names

• Evatocin (PH)
• Induxin (ID)
• NeOxyn (PH)
• Octocin (TH)
• Oksitocins (EE)
• Oxitone (AE, BH, CY, EG, IL, IQ, IR, JO, KW, LB, LY, OM, PH, QA, SA, SY, YE)
• Partocon INJ (FI)
• Pitocin (EC)
• Pitocin INJ (IN)
• Pitogin (ID)
• Piton S (ID)
• Piton S INJ (AE, BH, CY, EG, IQ, IR, JO, KW, LB, LY, NL, OM, QA, SA, SY, TW, YE)
• Santocyn (ID)
• Synthetic Oxytocin INJ (IN)
• Syntocinon (DK, HR, LU, PT)
• Syntocinon INJ (AR, AT, AU, BE, BF, BJ, BR, CH, CI, CN, DE, ES, ET, FI, FR, GB, GH, GM, GN, HK, IE, IT, KE, LR, MA, ML, MR, MU, MW, MX, MY, NE, NG, NL, NZ, PE, PH, PK, PL, PY, SC, SD, SE, SL, SN, TN, TZ, UG, UY, VE, ZA, ZM, ZW)
• Syntocinon Spray (AT, CH, NO, PL, SE)
• Udoxan (MY)
• Xitocin (MX)

Lexi-Comp.com

Last full review/revision January 2012

Content last modified January 2012