Drugs in labour Flashcards
What are some common drugs used in labour?
Oxytocin
Ergometrine
Prostaglandins
Misoprostol
Mifepristone
Nifedipine
Terbutaline
Carboprost
Tranexamic acid
Describe the normal release of oxytocin
Oxytocin is produced in the hypothalamus and is released by the posterior pituitary gland
What does oxytocin play a role in in labor?
Cervical ripening
Utrine contraction
(Lactation during breastfeeding)
Indications of oxytocin during birth
- Induce labour
- Progress labour
- Improve the frequency and strength of uterine contractions
- Prevent or treatpostpartum haemorrhage
What is the brand name for oxytocin?
Syntocinon
What is atosiban?
An oxytocin receptor antagonists used for tocolysis
What is the function of ergometrine?
Stimulates smooth muscle contraction of uterus and blood vessels
When may ergometrine be used?
During the 3rd stage of labour
Postpartum to prevent PPH
Only used after delivery!
What are some side effects of ergometrine?
Hypertension
Diarrhoea
Vomiting
Angina
What are some contraindications for ergometrine
Eclampsia
Hypertension (Significant caution)
What is syntometrine?
A combination drug of oxytocin and ergometrine
What is the function of prostaglandins in labour?
They stimulate contraction of the uterine muscles and have a role in cervical ripening
What is the main medical prostaglandin used in labour?
Prostaglandin E2 - Dinoprostone
What are the 3 main forms of medical prostaglandin E2
- Vaginalpessaries(Propess)
- Vaginaltablets(Prostintablets)
- Vaginalgel(Prostin gel)
MOA of misoprostol
Prostaglandin anologue
Uses of misoprostol
Medical management of miscarriage or intrauterine death (With mifeprostol)
Abortion (With mifepristone)
MOA of mifepristone
Anti-progesterone medication to halt pregnancy and ripen the cervix
Uses of mifepristone
IOL after intrauterine death
Abortions
(Both with misoprostol)
MOA of nifedipine
Ca2+ channel blocker that reduces smooth muscle contraction in blood vessels and the uterus
Uses of nifedipine in labour
Reduce BP in hypertension and pre-eclampsia
Tocolysis in premature labour
MOA of terbutaline
ß2 agonist - Acts on smooth muscle of the uterus to suppress uterine contractions
Uses of terbutaline
Tocolysis in uterine hyperstimulation
MOA of carboprost
Synthetic prostaglandin analogue - Stimulates uterine contraction
Uses of carboprost
Deep IM injection in PPH, where syntometrine not effective
Contraindication of carboprost
Asthma
MOA of tranexamic acid
Anti-fibrinolytic, binding to plasminogen and preventing conversion to plasmin (Plasminogen dissolves fibrin in blood clots), so tranexamic acid prevents breakdown of blood clots
Use of tranexamic acid
PPH
