Oxytocics and Tocolytics

Question 1

What are oxytocics?

Answer 1

Drugs that contract uterine muslces

Question 2

Name three classes of oxytocics.

Answer 2

Oxytocins
Ergot derivatives
Prostaglandins

Question 3

Where do oxytocics act?

Answer 3

Myometrial oxytocin receptor

voltage mediated calcium channels

Question 4

What physiological change happens during labour that is beneficial for the administration of oxytocics?

Answer 4

There is a 100-200 fold increase in myometrial oxytocin receptors during labour.

Question 5

What is the name of synthetic oxytocin?

Answer 5

Syntocinon

Question 6

Name a combo type of oxytocin and what it contains

Answer 6

Syntometrine = oxytocin + ergometrine

Question 7

Three indications of oxytocins

Answer 7

To induce a miscarriage or accelerate abortion
To induce labour
During the puerperium period, to minimise blood loss

Question 8

Compications of oxytocins

Answer 8

Uterine hyperstimulation:
- hypertonia aka increased DURATION of contraction
- polysystole = increased frequency of contraction

Uterine rupture - violent uterine contractions

Question 9

What releases the oxytocin?

Answer 9

Paraventricular nucleus of the hypothalamus creates the OT, then the POSTERIOR PITUITARY releases it.

Question 10

What stimulus is needed to release oxytocin naturally?

Answer 10

Stretching of the uterus stimulates the PVN to release

Question 11

Which drugs are used to induce miscarriage?

Answer 11

Gemeprost

Question 12

Which drug is used in the medical termination of pregnancy?

Answer 12

Misoprostol
Mifepristone

Question 13

MOA of misoprostol

Answer 13

Synthetic prostaglandin analgoue

Question 14

MOA of mifepristone

Answer 14

Progesterone + glucocorticoid receptor anatagonist.

Question 15

What drug is used to induce labour?

Answer 15

Dinoprostone - tablets, pessaries, or vaginal gel

Question 16

Is Prostin E2 vaginal gel bioequivalent to Prostin E2 vaginal tablets?

Answer 16

No - if you take time x, the level in the body would be different.

Question 17

What drug is used to induce or augment labour? What is done with this?

Answer 17

Oxytocin - ARM - assisted rupture of membranes aka amniotomy

Question 18

Oxytocin drug delivery

Answer 18

Slow IV infusion

Question 19

Complications of oxytocin

Answer 19

hyperstimulation of the uterus
excessive fluid retention

Question 20

3 drugs used in labour induction

Answer 20

Dinoprostone
Oxytocin
Misoprostol (unlicensed)

Question 21

Drug during prevention or treatment of bleeding with incomplete miscarriage

Answer 21

Ergometrine + oxytocin IM

(Syntometrine)

Question 22

Drug used in third stage of labour to reduce risk of PPH

Answer 22

Ergometrine 500mcg + oxytocin 5units IM

(Syntometrine)

Question 23

When is syntometrine contraindicated and why?

Answer 23

In pre-eclampsia as ergometrine can increase BP as it is a vasoconstrictor

Question 24

If a pt is unresponsive to syntometrine but has a PPH, what can you give?

Answer 24

Carboprost 250mcg/ml injections

OR misoprostol but this would be unlicensed.

Question 25

What drug is used for the prevention of uterine atony after c -section?

Answer 25

Carbetocin 100mcg IV

Question 26

Name a tocolytic used for inhibition of uncomplicated premature labour

Answer 26

Atosiban

Question 27

Name some other drugs used as tocolytics

Answer 27

Nifedipine
Salbutamol
Terbutalne
Indomethacin