Oxytocin Injection

Oxytocin comes as a solution (liquid) to be given intravenously (into a vein) or intramuscularly (into the muscle) by a doctor or healthcare provider in a hospital or clinic. If oxytocin injection is given to induce labor or to increase contractions, it is usually given intravenously with medical supervision in a hospital.

Your doctor may adjust your dose of oxytocin injection during your treatment, depending on your contraction pattern and on the side effects that you experience. Talk to your doctor about how you are feeling during your treatment with oxytocin injection.

• Pitocin^®

Pitocin (Oxytocin Injection, USP) Synthetic is available as follows:

NDC 42023-130-06 Packages of six 50 mL Pharmacy Bulk Packages, each containing 10 units of oxytocin per mL (total = 500 units of oxytocin per vial).

Storage

Store between 20° to 25°C (68° to 77°F). See USP Controlled Room Temperature.

REFERENCES

1. Seitchik J, Castillo M: Oxytocin augmentation of dysfunctional labor. I. Clinical data. Am J Obstet Gynecol 1982; 144:899-905.

2. Seitchik J, Castillo M: Oxytocin augmentation of dysfunctional labor. II. Multiparous patients. Am J Obstet Gynecol 1983; 145:777-780.

3. Fuchs A, Goeschen K, Husslein P, et al: Oxytocin and the initiation of human parturition. III. Plasma concentrations of oxytocin and 13, 14-dihydro-15-keto-prostaglandin F2a in spontaneous and oxytocin-induced labor at term. Am J Obstet Gynecol 1983; 145:497-502.

4. Seitchik J, Amico J, et al: Oxytocin augmentation of dysfunctional labor. IV. Oxytocin pharmacokinetics. Am J Obstet Gynecol 1984; 150:225-228.

5. American College of Obstetricians and Gynecologists: ACOG Technical Bulletin Number 110- November 1987: Induction and augmentation of labor.

Manufactured and Distributed by: JHP Pharmaceuticals, LLC, Rochester, MI 48307. Revised: Mar 2013.

The following adverse reactions have been reported in the mother:

Anaphylactic reaction
Premature ventricular contractions
Postpartum hemorrhage
Pelvic hematoma
Cardiac arrhythmia
Subarachnoid hemorrhage
Fatal afibrinogenemia
Hypertensive episodes
Nausea
Rupture of the uterus
Vomiting

Excessive dosage or hypersensitivity to the drug may result in uterine hypertonicity, spasm, tetanic contraction, or rupture of the uterus.

The possibility of increased blood loss and afibrinogenemia should be kept in mind when administering the drug.

Severe water intoxication with convulsions and coma has occurred, associated with a slow oxytocin infusion over a 24-hour period. Maternal death due to oxytocin-induced water intoxication has been reported.

The following adverse reactions have been reported in the fetus or neonate:

For medical advice about adverse reactions contact your medical professional. To report SUSPECTED ADVERSE REACTIONS, contact JHP at 1-866-923-2547 or MEDWATCH at 1-800-FDA-1088 (1- 800-332-1088) or http://www.fda.gov/medwatch/.

Pitocin, when given for induction of labor or augmentation of uterine activity, should be administered only by the intravenous route and with adequate medical supervision in a hospital.

Uterine motility depends on the formation of the contractile protein actomyosin under the influence of the Ca2+ dependent phosphorylating enzyme myosin light-chain kinase. Oxytocin promotes contractions by increasing the intracellular Ca2+. Oxytocin has specific receptors in the myometrium and the receptor concentration increases greatly during pregnancy, reaching a maximum in early labor at term. The response to a given dose of oxytocin is very individualized and depends on the sensitivity of the uterus, which is determined by the oxytocin receptor concentration. However, the physician should be aware of the fact that oxytocin even in its pure form has inherent pressor and antidiuretic properties which may become manifest when large doses are administered. These properties are thought to be due to the fact that oxytocin and vasopressin differ in regard to only two of the eight amino acids (see PRECAUTIONS section).

Oxytocin is distributed throughout the extracellular fluid. Small amounts of the drug probably reach the fetal circulation. Oxytocin has a plasma half-life of about 1 to 6 minutes which is decreased in late pregnancy and during lactation. Following intravenous administration of oxytocin, uterine response occurs almost immediately and subsides within 1 hour. Following intramuscular injection of the drug, uterine response occurs within 3 to 5 minutes and persists for 2 to 3 hours. Its rapid removal from plasma is accomplished largely by the kidney and the liver. Only small amounts are excreted in urine unchanged.

Consult your pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Consult your pharmacist.

Keep a list of all your medications with you, and share the list with your doctor and pharmacist.