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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

U.S. Brand Names

• Pitocin®

Canadian Brand Names

• Pitocin®
• Syntocinon®

Pharmacologic Category

• Oxytocic Agent

Use: Labeled Indications

Induction of labor at term; control of postpartum bleeding; adjunctive therapy in management of abortion

Pregnancy Risk Factor

X

Pregnancy Considerations

[U.S. Boxed Warning]: To be used for medical rather than elective induction of labor. 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; 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)

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 and excess uterine contractions).

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

• Water intoxication: Severe water intoxication with convulsions, coma, and death is associated with a slow oxytocin infusion over 24 hours.

Other warnings/precautions:

• Appropriate use: [U.S. Boxed Warning]: To be used for medical rather than elective induction of labor.

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, hypertensive episodes, premature ventricular contractions

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

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 oxytocin at 2°C to 8°C (36°F to 46°F); do not freeze. Pitocin® may also be stored at 15°C to 25°C (59°F to 77°F) for up to 30 days.

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 dextran 6% in dextrose, dextran 6% in NS, D₅LR, D₅1/4NS, D₅1/2NS, D₅NS, D₅W, D₁₀W, LR, 1/2NS, NS.

Y-site administration: Compatible: Heparin, hydrocortisone sodium succinate, insulin (regular), meperidine, morphine, potassium chloride, vitamin B complex with C, warfarin.

Compatibility when admixed: Compatible: Chloramphenicol, metaraminol, sodium bicarbonate, thiopental, verapamil. Incompatible: Fibrinolysin (human), norepinephrine, prochlorperazine edisylate, warfarin. Variable (consult detailed reference): Phytonadione.

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: 1-5 minutes

Excretion: Urine

Dosage

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

Induction of labor: I.V.: 0.5-1 milliunits/minute; gradually increase dose in 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.

Postpartum bleeding:

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

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.

Refer to Reconstitution for dilution information. An infusion pump is required for administration.

Monitoring Parameters

Fluid intake and output during administration; 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)

References

de Groot AN, van Dongen PW, Vree TB, et al, “Ergot Alkaloids. Current Status and Review of Clinical Pharmacology and Therapeutic Use Compared With Other Oxytocics in Obstetrics and Gynaecology,” Drugs, 1998, 56(4):523-35.

International Brand Names

• Evatocin (PH)
• Induxin (ID)
• NeOxyn (PH)
• Octocin (TH)
• Oksitocins (EE)
• Otoxin (PH)
• 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, IL, 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, 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 March 2011

Content last modified March 2011