Oxytocin

OBG

1. Pharmacotherapy in Obstetric
& Gynaecology: OXYTOCIN
NAZNEEN VAHORA
CLINICAL INSTRUCTOR
MTIN,CHANGA

2. ACTIONACTION
It is released in large amounts after distension of cervix
and vagina, nipple stimulation.
It contracts smooth muscle helping the expulsion of the
foetus and ejection of breastmilk.
It also crosses the placenta and acts on the foetus
neurons to prepare it for delivery- to sedate the brain.
Rapid acting: 1 minute if given IV; 3-7 minutes if given
IM and lasts 30-60 minutes.

3. POTENTIAL ADVERSE POTENTIAL ADVERSE
REACTIONSREACTIONS
Seizures, subarachnoid haemorrhage
Tachycardia, hypotension, arrythymias
GU: uterine rupture, pelvic hamatoma, PPH, hypertonic
uterine contractions
Foetal distress from Hypertonic U- increases c/s rate
Rapid or prolonged infusion causes water retention
Neonatal jaundice –crosses placenta.
Do not give rapid IV bolus for PPH ; hypotension

4. Large doses- sustained contraction(↓ placental
blood flow & fetal hypoxia/death)

5. SOURCESSOURCES
Corpus Luteum
PLACENTA ( may be foetus starts the
labour)
Synthetic pitocin

7. USESUSES
Augmentation labour
Induction labour
PPH
Retained products conception
PIH patients – post partum

8. •Clinical use:
- IOL (IVI 3U syntocinon+50 ml of saline)
- Augment slow labour (IVI same as above)
3
rd
stage of labour- 5 U IM for HTN ,
cardiac disease- IVI 40 U in 500ml saline ( PPH)
Surgical termination of preg./ERPC (Evacuation of
retained products of conception) - 5U slow IV

9. ASSESSMENT BEFORE ASSESSMENT BEFORE
augmentation/ inductionaugmentation/ induction
Previous c/s or other uterine surgery?
Twins?
CPD? History of CPD or borderline now.
Foetal distress?
Malpresentation including cord presentation
Praevia
Bishop score ( induction)

11. DOSAGESDOSAGES
Post partum -10u IMI on delivery of baby.
Can be repeated.
PPH & RPOC (retained products of
conception) – 20u in 1 liter MRL run @ 20ml
/hr
Augmentation primipara- 5u in 1 liter RL
titrated via IVAC to get regular contractions
and reactive CTG (5ml/hr increasing 1 ml/hr)
Augmentation multipara – 2 u in 1 liter RL
titrated via IV to give regular contractions &
reactive CTG

12. Pitocin should be piggybacked so that it can
be stopped if necessary and IV line can then
run.
Pitocin is used for PIH patients because
syntometrine contains ergometrine (+pitocin)
and it causes round muscle contraction –
veins/arteries- so raises blood pressure.
Pitocin can also be injected into placental
umbilical vein to get separation. (10u in 10ml)

13. STORAGESTORAGE
15-25
o
C – i.e. a fridge item.

14. PIGGYBACK IVPIGGYBACK IV