Drugs of pregnancy, labour and post partum care

Question 1

What is the half life of oxytocin?

Answer 1

5 minutes

Question 2

What is the half life of misoprostol?

Answer 2

20-40 minutes

Question 3

What is the half life of ergometrine?

Answer 3

30-120 minutes

Question 4

What is a uterotonic?

Answer 4

Drugs that cause uterine contraction

Question 5

What drug causes St Anthony’s fire?

Answer 5

Ergometrine

Question 6

What is St Anthony’s fire?

Answer 6

Otherwise referred to as ergotism or ergot poisoning - it is a potential toxic side effect of ergometrine - due to ergot alkaloid toxicity - it can cause dry gangrene and convulsions

Question 7

What is oxytocin?

Answer 7

A nanopetide produced in the hypothalamus and released by the posterior pituitary gland- it is a uterotonic - it stimulates uterine contraction

Question 8

What is misoprostol?

Answer 8

A synthetic prostaglandin, an analogue of prostaglandin E1

Question 9

Why is ergometrine regulated?

Answer 9

Chemically similar to LSD and can be used to manufacture LSD

Question 10

What kind of drugs are carbegoline and bromocriptine?

Answer 10

D2 dopamine receptor agonists - they suppress prolactin and therefore can be used in treatment of prolactinomas and suppression of lactation

Question 11

What kind of drug is prochlorperazine?

Answer 11

dopamine D2 receptor antagonist

Question 12

What kind of drug is ondansetron?

Answer 12

serotonin 5HT3 antagonist

Question 13

What kind of drug is cyclizine?

Answer 13

Histamine H1 receptor antagonist

Question 14

What kind of drug is promethazine?

Answer 14

Histamine H1 receptor antagonist

Question 15

What is carbergoline?

Answer 15

A D2 agonist used to suppress lactation (inhibits prolactin)

Question 16

What is bromicriptine?

Answer 16

A D2 agonist used to suppress lactation (inhibits prolactin)

Question 17

What is domperidone?

Answer 17

A dopamine antagonist - stimulates lactation

Question 18

Morphine vs. diamorphine

Answer 18

diamorphine prodrug of morphine, more lipophilic, can cross blood brain barrier

Question 19

Where is methadone stored in the fetus?

Answer 19

liver, lung, spleen

Question 20

When are the symptoms of neonatal narcotic abstinence syndrome seen?

Answer 20

may occur in first 48 hours or can occur within 4 weeks (methadone is stored by fetal tissues - lung/liver/spleen)

Question 21

Features of neonatal narcotic abstinence syndrome

Answer 21

iritability, poor feeding, hyperreflexia/hypertonic, high pitched cry, respiratory distress, seizures

Question 22

What are the features of lidocaine anaesthesia toxicity?

Answer 22

perioral/tongue numbness
metallic taste
tinnitus
blurred vision
seizures or LOC
widening PR/QRS
Cardiovascular compromise
cardiac toxicity

Question 23

In which conditions would you avoid lidocaine?

Answer 23

patients with heart conditions particularly wPw syndrome

Question 24

What are the features of wolf-Parkinson-white syndrome?

Answer 24

cardiac pre-excitation syndrome due to an accessory pathway (bundle of kent) - delta waves on ECG - predispose to risk of supraventricular tachycardias

Question 25

Max dose of lidocaine with adrenaline?

Answer 25

7mg/kg

Question 26

max dose of lidocaine without adrenaline?

Answer 26

3-5mg/kg

Question 27

Which receptors does lidocaine act?

Answer 27

Fast-voltage gated sodium channels

Question 28

How does clomifene affect fertility?

Answer 28

selective oestrogen receptor modulator Blocks oestrogen receptors of the hypothalamus Leads to reflex increase in Gnrh and therefore FSH/LH

Question 29

What receptor type does oxytocin bind to?

Answer 29

G-couple protein receptors

Question 30

Preferred first line treatment of hyperthyroidism in pregnancy

Answer 30

propylthiouracil Carbimazole crosses the placenta too easily and is associated with congenital abnormalities (choanal atresia, aplasia cutis)

Question 31

Which drug is an oxytocin receptor antagonis?

Answer 31

atosiban

Question 32

What molecules are required for oxytocin receptor functioning?

Answer 32

cholesterol and magnesium

Question 33

Hypothesised action of oxytocin on fetal brain

Answer 33

reduces effect of hypoxic insult by inducing a switch of GABA signalling from excitatory to inhibitory

Question 34

Side effects of oxytocin

Answer 34

hypertension, tachycardia, increased cardiac output Can cause arrythmia can cause uterine rupture can have same effect as ADH and cause oliguria, water intoxication risk of seizure and subarachnoid haemorrhage

Question 35

What are prostaglandins derived from?

Answer 35

fatty acids

Question 36

What is prostaglandin E1 used for?

Answer 36

misoprostol (synthetic prostaglandin E1) is used for PPH and termination of pregnancy

Question 37

What is prostaglandin E2 used for?

Answer 37

Dinoprostone is used for induction of labour (cervical ripening)

Question 38

What is prostaglandin F2alpha used for?

Answer 38

Dinoprost or carboprost is used for termination of pregnancy, induction of labour and PPH

Question 39

What is dinoprost?

Answer 39

a naturally occurring prostaglandin (F alpha)

Question 40

What is carboprost?

Answer 40

synthetic prostaglandin F alpha | used for termination/PPH/induction of labour

Question 41

What is dinoprostone?

Answer 41

naturally occurring prostaglandin E2 used in labour induction

Question 42

Non-uterine use of misoprostol

Answer 42

synthetic prostaglandin E1 is also used in gastric acid prevention by inhibition of adenylate cyclase in parietal cells

Question 43

Which prostaglandin is associated with transient hyperthermia?

Answer 43

dinoprostone (E2) analogue

Question 44

What are the different tocolytic mechanisms?

Answer 44

oxytocin receptor antagonist calcium channel blocker NSAIDs Beta 2 agonists

Question 45

How is atosiban administered?

Answer 45

IV