Carcinogenesis, Mutagenesis, Impairment of Fertility
There are no animal or human studies on the carcinogenicity and mutagenicity of this drug, nor is there any information on its effect on fertility.
Animal reproduction studies have not been conducted with oxytocin. There are no known indications for use in the first trimester of pregnancy other than in relation to spontaneous or induced abortion. Based on the wide experience with this drug and its chemical structure and pharmacological properties, it would not be expected to present a risk of fetal abnormalities when used as indicated.
See ADVERSE REACTIONS in the fetus or infant.
Overdosage with oxytocin depends essentially on uterine hyperactivity, whether or not due to hypersensitivity to this agent. Hyperstimulation with strong (hypertonic) or prolonged (tetanic) contractions, or a resting tone of 15-20 mm H2O or more between contractions can lead to tumultuous labor, uterine rupture, cervical and vaginal lacerations, postpartum hemorrhage, uteroplacental hypoperfusion, and variable deceleration of fetal heart, fetal hypoxia, hypercapnia, or death. Water intoxication with convulsions, which is caused by the inherent antidiuretic effect of oxytocin, is a serious complication that may occur if large doses (40-50 mL/minute) are infused for long periods. Treatment of water intoxication consists of discontinuation of oxytocin, restriction of fluid intake, diuresis, IV hypertonic saline solution, correction of electrolyte imbalance, control of convulsions with judicious use of a barbiturate, and special nursing care for the comatose patient.
Syntocinon® (oxytocin) injection is contraindicated in any of the following conditions: Significant cephalopelvic disproportion; unfavorable fetal positions or presentations which are undeliverable without conversion prior to delivery (transverse lies); i.e., in obstetrical emergencies where the benefit-to-risk ratio for either the fetus or the mother favors surgical intervention; in cases of fetal distress where delivery is not imminent; prolonged use in uterine inertia or severe toxemia; hypertonic uterine patterns; patients with hypersensitivity to the drug; induction or augmentation of labor in those cases where vaginal delivery is contraindicated, such as cord presentation or prolapse, total placental previa, and vasa previa.