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 ADVERSEPOTENTIAL 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)
 3rd
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 BEFOREASSESSMENT 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
 15-25o
C – i.e. a fridge item.

14. PIGGYBACK IVPIGGYBACK IV