Generic
Oxytocin
10 brands available in the market
At a glance
Oxytocin is a hormone and medication used for induction of labor, stimulation of uterine contractions, prevention and treatment of postpartum hemorrhage and stimulation of lactation.
Description
Oxytocin is a synthetic hormone identical to natural posterior pituitary hormone. It causes uterine contractions, mimicking normal spontaneous labor and transiently impeding uterine blood flow. It also stimulates smooth muscle associated with secretory epithelium of the lactating breast causing milk ejection.
Indications
- Induction of labor
- Stimulation of uterine contractions
- Prevention and treatment of secondary postpartum hemorrhage
- Adherent placenta
- Stimulation of lactation
- Treatment of incomplete abortion (to prevent secondary hemorrhage)
Therapeutic class
Drugs Acting on the Uterus
Pharmacological class
Uterine Stimulant
Pharmacology
Oxytocin binds to specific receptors in uterine smooth muscle to increase intracellular calcium, activating myosin light chain kinase to cause uterine contractions. It also increases local prostaglandin production which further stimulates contraction.
Mechanism of action
Stimulates uterine contractions for labor induction and postpartum hemorrhage control.
Dosage
Labor Induction (IV):
- 0.5-1 mUnit/min (initial); titrate 1-2 mUnit/min q15-60min until contraction pattern similar to normal labor (usually 6 mUnit/min)
- Decrease dose after desired frequency reached and labor progressed to 5-6 cm dilation
Postpartum Hemorrhage (IV): 10-40 units (max 40 units) in 1000 mL nonhydrating IV solution
Incomplete Abortion (IV): 10-20 mUnit/min; not to exceed 30 units/12 hr
IM: 2-5 IU (postpartum); 2 IU (lactation); 2-5 IU every 30-60 min (incomplete abortion)
Administration
- Administered by doctor or nurse as IV infusion or IM injection
- IV: Use controlled infusion device
- IM: Do not exceed 0.5-1 IU per injection (irregular response and overdose symptoms)
Missed dose
Not generally applicable (scheduled administration); consult doctor if needed.
Side effects
Common Side Effects:
- Vomiting
- Headache
- Uterine contractions
- Nausea
- Uterine hypertonicity, spasm, titanic contraction or uterine rupture
- Water intoxication (with convulsions and coma)
- Cardiac arrhythmias
- Anaphylactic reaction
Precautions & warnings
- Uterine sensitivity varies; use lowest effective dose
- Monitor fetal heart rate and maternal blood pressure
- Caution if uterine or cervical scars exist
- Caution while driving (contractions may begin)
Contraindications
- Cephalopelvic disproportion
- Abnormal presentation of fetus
- Hydramnios
- Multiparae
- Previous caesarean section or other uterine surgery
- Hyperactive or hypertonic uterus
- Contraindicated vaginal delivery (invasive cervical cancer, active genital herpes, cord prolapse, total placenta previa)
- Fetal distress where delivery is not imminent
- Severe pre-eclamptic toxaemia
Drug interactions
- Severe hypertension if given within 3-4 hr of vasoconstrictor
- Hypotension and sinus bradycardia with cyclopropane anaesthesia
- Dinoprostone and misoprostol increase uterotonic effect (do not use within 6 hr of vaginal prostaglandins)
- Increased vasopressor effect with sympathomimetics
Food interactions
Safety with alcohol not known; consult doctor.
Use in pregnancy
Use in Pregnancy: Oxytocin is safe during pregnancy; low or no risk to fetus.
Pregnancy Category: A — always consult a doctor before taking during pregnancy.
Use in lactation
Use in Lactation: Oxytocin is safe during breastfeeding; not significantly excreted in breast milk.
Pediatric use
Not indicated for children.
Geriatric use
Use as needed.
Renal / hepatic impairment
Renal Impairment: Caution in severe kidney disease; limited information.
Hepatic Impairment: Limited information; consult doctor.
Overdose effects
Overdose: Violent uterine contractions, fetal bradycardia, arrhythmias, tissue laceration, uterine rupture, fetal or maternal death; discontinue infusion and induce tocolysis.
Storage conditions
Store at 2-8°C, in dark and frost-free place; keep out of reach of children.
Chemical structure
Oxytocin