Oxytocin-a peptide hormone and neuropeptide

Oxytocin is a peptide hormone and neuropeptide. Oxytocin is also used as a medication to facilitate childbirth. Oxytocin is normally produced by the paraventricular nucleus of the hypothalamus and released by the posterior pituitary

Oxytocin-a peptide hormone and neuropeptide

Pitocin; Ocytocin; Syntocinon

Evatocin, Genox, Foetocin, Gynotocin, Meritocin, Indox, Nitocin, Oxybro INJ, Oxitocin, Oxystar, Oxycare, Oxytocin INJ, Oxytzone, Oxyton-5, Partocin, Saytocin, Pitocin, Syntocinon, Zygon, Zetocin.

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Indirectly stimulates contraction of uterine smooth muscle by increasing the sodium permeability of uterine myofibrils. Increases contraction amplitude and frequency, which tends to decrease cervical activity, produce dilation and effacement of the cervix, and transiently impede uterine blood flow; contractions produced by oxytocin at term are similar to those occurring during spontaneous labor. High estrogen concentrations lower the threshold for uterine response to oxytocin. 

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Uterine stimulant

Foetus or neonate: Jaundice; arrhythmias, bradycardia; brain, CNS damage; seizure; retinal haemorrhage; low Apgar score. transient hypotension, nasal irritation, reflex tachycardia; rhinorrhoea, uterine bleeding, lachrymation (following nasal admin); violent contractions, hypertonicity; spasm; nausea, vomiting.

• Possible severe hypertension if given within 3-4 hr of vasoconstrictor in association with caudal block anaesthesia.
• Maternal sinus bradycardia with abnormal AV rhythms and Cyclopropane anaesthesia may increase risk of hypotension.
• Concomitant use with prostaglandins increases risk of uterine rupture and cervical lacerations.
• Misoprostol and dinoprostone may increase uterotonic effect of oxytocin, thus oxytocin should not be used within 6 hr after admin of vaginal prostaglandins.
• Concurrent use may increase the vasopressor effect of sympathomimetics.

Cephalopelvic disproportion; abnormal presentation of the foetus; hydraminios; multiparae; previous caesarian section or other uterine surgery; hyperactive or hypertonic uterus, uterine rupture; contraindicated vaginal delivery (invasive cervical cancer, active genital herpes, prolapse of the cord, cord presentation, total placenta previa or vasa previa); foetal distress where delivery is not imminent; severe pre-eclamptic toxaemia.

Store at 2-8 °C. 

Molecular weight

1007.187 Da

Molecular formula

C43H66N12O12S2

CAS number

50-56-6

Precautions

• CV disorders; >35 years; lactation.
• Monitor foetal and maternal heart rate, maternal BP and uterine motility.
• Monitor fluid intake and output during treatment.
• Discontinute immediately if the uterus is hypertonic or hyperactive or if there is foetal distress.
• Use of nasal spray may produce maternal dependence on its effects.
• IM admin not regularly used due to unpredictable effects of oxytocin.
• Not to be used for prolonged periods in severe pre-eclampsia, resistant uterine inertia, or severe CV disorders.
• Risk of water intoxication when used at high doses for prolonged periods.