oxytocin(redirected from Receptors, oxytocin)
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Pharmacologic class: Posterior pituitary hormone
Therapeutic class: Uterine-active agent
Pregnancy risk category NR
FDA Box Warning
• Drug isn't indicated for elective induction of labor (defined as initiation of labor in pregnant woman with no medical indications for induction). Available data aren't adequate to evaluate benefits versus risk.
Unknown. Thought to directly stimulate smooth muscle contractions in uterus and cervix.
Injection: 10 units/ml ampule or vial
Indications and dosages
➣ To induce or stimulate labor
Adults: Initially, 1-ml ampule (10 units) in compatible I.V. solution infused at 1 to 2 milliunits/minute (0.001 to 0.002 units/minute). Increase rate in increments of 1 to 2 milliunits/minute q 15 to 30 minutes until acceptable contraction pattern is established.
➣ To control postpartum bleeding
Adults: 10 to 40 units in compatible I.V. solution infused at rate adequate to control bleeding; or 10 units I.M. after placenta delivery
➣ Incomplete abortion
Adults: 10 units in compatible I.V. solution infused at 10 to 20 milliunits/minute (0.01 to 0.02 units/minute)
• Antepartal fetal heart rate testing
• Breast enlargement
• Hypersensitivity to drug
• Cephalopelvic disproportion
• Fetal distress when delivery is not imminent
• Prolonged use in uterine inertia or severe toxemia
• Hypertonic or hyperactive uterine pattern
• Unfavorable fetal position or presentation that's undeliverable without conversion
• Labor induction or augmentation when vaginal delivery is contraindi-cated (as in invasive cervical cancer, active genital herpes, or total placenta previa)
Use cautiously in:
• previous cervical or uterine surgery, history of uterine sepsis
• breastfeeding patients.
• Reconstitute by adding 1 ml (10 units) to 1,000 ml of normal saline solution, lactated Ringer's solution, or dextrose 5% in water.
☞ Don't give by I.V. bolus injection.
• Infuse I.V. using controlled-infusion device.
• Be aware that drug isn't routinely given I.M.
• Know that drug should be given only to inpatients at critical care facilities when prescriber is immediately available.
CNS: seizures, coma, neonatal brain damage, subarachnoid hemorrhage
CV: premature ventricular contractions, arrhythmias, neonatal bradycardia
GI: nausea, vomiting
GU: postpartal hemorrhage; pelvic hematoma; uterine hypertonicity, spasm, or tetanic contraction; abruptio placentae; uterine rupture (with excessive doses)
Hepatic: neonatal jaundice
Other: hypersensitivity reactions including anaphylaxis, low 5-minute Apgar score (neonate)
Drug-drug. Sympathomimetics: postpartal hypertension
Thiopental anesthetics: delayed anesthesia induction
Vasoconstrictors: severe hypertension (when given within 3 to 4 hours of oxytocin)
Drug-herbs. Ephedra (ma huang): increased hypertension
☞ Continuously monitor contractions, fetal and maternal heart rate, and maternal blood pressure and ECG. Discontinue infusion if uterine hyper-activity occurs.
☞ Monitor patient extremely closely during first and second stages of labor because of risk of cervical laceration, uterine rupture, and maternal and fetal death.
• When giving drug to control postpartal bleeding, monitor and record vaginal bleeding.
• Assess fluid intake and output. Watch for signs and symptoms of water intoxication.
• Inform patient about risks and benefits of oxytocin-induced labor.
☞ Teach patient to recognize and immediately report adverse drug effects.