Core pharmacology

Class Group

OXYTOCIC

Legacy Cicm Level

Level 3

Introduction

Glycopeptide

Indications Uses

1. Induce or augment labor
2. Facilitate delivery of placenta
3. PPH
4. Miscarriage

Main Action

1. Oxytocin GPCR → IP3/DAG increase calcium in uterus promoting uterine contraction
2. Cervical dilation

Adverse Effects Toxicity

1. Mild diuretic effect with hyponatraemia if hypotonic fluids used (similar to vasopressin)
2. Hypotension if bolus given (generally 5U slow push)
3. Administration via IV lines as blood/plasma may lead to rapid inactivation by plasma oxytocinase
4. Uterine rupture if excessive doses administered rapidly

Absorption

IV or IM

Half-life

T1/2= 3-5min (rapidly hydrolyzed by plasma oxytocinases)