Classifications: hormone; oxytocic; Therapeutic: oxytocic
Pregnancy Category: X
10 units/mL injection
Synthetic, water-soluble polypeptide consisting of eight amino acids, identical pharmacologically to the oxytocin released
by posterior pituitary. By direct action on myofibrils, produces phasic contractions characteristic of normal delivery. Uterine
sensitivity to oxytocin increases during gestation period and peaks sharply before parturition.
Effective in initiating or improving uterine contractions at term.
To initiate or improve uterine contraction at term, management of inevitable, incomplete, or missed abortion; stimulation
of uterine contractions during third stage of labor; stimulation to overcome uterine inertia; control of postpartum hemorrhage
and promotion of postpartum uterine involution. Also used to induce labor in cases of maternal diabetes, preeclampsia, eclampsia,
and erythroblastosis fetalis.
Hypersensitivity to oxytocin; significant cephalopelvic disproportion, unfavorable fetal position or presentations that
are undeliverable without conversion before delivery, obstetric emergencies in which benefit-to-risk ratio for mother or
fetus favors surgical intervention, fetal distress in which delivery is not imminent, prematurity, placenta previa, prolonged
use in severe toxemia or uterine inertia, hypertonic uterine patterns, previous surgery of uterus or cervix including cesarean
section, conditions predisposing to thromboplastin or amniotic fluid embolism (dead fetus, abruptio placentae), grand multiparity,
invasive cervical carcinoma, primipara greater than 35 y of age, past history of uterine sepsis or of traumatic delivery,
intranasal route during labor, simultaneous administration of drug by two routes.
Concomitant use with cyclopropane anesthesia or vasoconstrictive drugs.
Route & Dosage
Adult: IV 0.52 mU/min, may increase by 12 mU/min q1560min (max: 20 mU/min) dose is decreased when labor is established.
High dose regimen: 6 mU/min, may increase by 6 mU/min q1560min until contraction pattern established
Adult: IM 10 U total dose IV Infuse a total of 1040 U at a rate of 2040 mU/min after delivery
Adult: IV 1020 mU/min
PREPARE: IV Infusion: When diluting oxytocin for IV infusion, rotate bottle gently to distribute medicine throughout solution. IV Infusion for Inducing Labor: Add 10 U (1 mL) to 1 L of D5W, NS, RL, or D5NS to yield 10 mU/mL. IV Infusion for Postpartum Bleeding/Incomplete Abortion: Add 1040 U (14 mL) to 1 L of D5W, NS, RL, or D5NS to yield 1040 mU/mL.
ADMINISTER: IV Infusion: Use an infusion pump for accurate control of infusion rate. IV Infusion for Inducing Labor: Initially infuse 0.52 mU/min; increase by 12 mU/min at 3060 min intervals. IV Infusion for Postpartum Bleeding: Initially infuse 1040 mU/min, then adjust to control uterine atony. IV Infusion for Incomplete Abortion: Infuse 1020 mU/min. Do not exceed 30 U in 12 h.
INCOMPATIBILITIES Solution/additive: Fibrinolysin, norepinephrine, prochlorperazine, warfarin.
Adverse Effects (≥1%)Body as a Whole:
Fetal trauma from too rapid propulsion through pelvis, fetal death,
anaphylactic reactions, postpartum hemorrhage, precordial pain, edema, cyanosis or redness of skin. CV:
Fetal bradycardia and arrhythmias, maternal cardiac arrhythmias, hypertensive episodes, subarachnoid hemorrhage,
increased blood flow, fatal afibrinogenemia,
ECG changes, PVCs, cardiovascular spasm and collapse. GI: Neonatal jaundice
, maternal nausea, vomiting. Endocrine:
ADH effects leading to severe water intoxication and hyponatremia, hypotension. CNS:
Fetal intracranial hemorrhage,
, maternal dyspnea
Uterine hypertonicity, tetanic contractions, uterine rupture,
cause severe hypertension; cyclopropane anesthesia
causes hypotension, maternal bradycardia, arrhythmias. Herbal: Ephedra, ma huang
may cause hypertension.
1 h. Distribution:
Distributed throughout extracellular fluid; small amount may cross placenta. Metabolism:
Rapidly destroyed in liver and kidneys. Elimination:
Small amounts excreted unchanged in urine. Half-Life:
Assessment & Drug Effects
- Start flow charts to record maternal BP and other vital signs, I&O ratio, weight, strength, duration, and frequency of contractions,
as well as fetal heart tone and rate, before instituting treatment.
- Monitor fetal heart rate and maternal BP and pulse at least q15min during infusion period; evaluate tonus of myometrium
during and between contractions and record on flow chart. Report change in rate and rhythm immediately.
- Stop infusion to prevent fetal anoxia, turn patient on her side, and notify physician if contractions are prolonged (occurring
at less than 2-min intervals) and if monitor records contractions about 50 mm Hg or if contractions last 90 sec or longer.
Stimulation will wane rapidly within 23 min. Oxygen administration may be necessary.
- If local or regional (caudal, spinal) anesthesia is being given to the patient receiving oxytocin, be alert to the possibility
of hypertensive crisis (sudden intense occipital headache, palpitation, marked hypertension, stiff neck, nausea, vomiting,
sweating, fever, photophobia, dilated pupils, bradycardia or tachycardia, constricting chest pain).
- Monitor I&O during labor. If patient is receiving drug by prolonged IV infusion, watch for symptoms of water intoxication
(drowsiness, listlessness, headache, confusion, anuria, weight gain). Report changes in alertness and orientation and changes
in I&O ratio (i.e., marked decrease in output with excessive intake).
- Check fundus frequently during the first few postpartum hours and several times daily thereafter.
- Incidence of hypersensitivity or allergic reactions is higher when oxytocin is given by IM or IV injection rather than by
IV infusion (diluted solution).
Patient & Family Education
- Be aware of purpose and anticipated effect of oxytocin.
- Report sudden, severe headache immediately to health care providers.