Pharmacology during pregnancy

Question 1

why might a woman be on medication during pregnancy?

Answer 1

epilepsy
athsma
hypertension
long term anticoagulant therapy use i.e. atrial fibrillation
diabetes
mental health disorders
migraine

Question 2

how does oestrogen and progesterone have an effect on metabolism and why?

Answer 2

they can increase or decrease metabolism as they can induce or inhibit liver P450 enzymes

Question 3

is the excretion of drugs increased or decreased during pregnancy and why?

Answer 3

excretion is increased due to increased GFR

therefore reduces plasma concentration and the need of a higher dose of renal excreted drugs

Question 4

what factors determine placental transfer of drugs?

Answer 4

molecular weight (smaller sizes cross more easily)
polarity (non-polar cross more easily
lipid solubility

Question 5

at what molecular weight does drugs cross the placenta?

Answer 5

<500 Da

Question 6

when is risk of teratogenicity at highest?

Answer 6

first trimester

organogenesis (3-8 weeks)

Question 7

when is fetotoxicity highest?

Answer 7

2nd and 3rd trimester

Question 8

give examples of drugs which cause folate antagonism?

Answer 8

methotrexate
trimethoprim
carbamezapine
phenytoin
valproate

Question 9

what are the 2 processes that cause folate antagonism?

Answer 9

block the conversion of folate to THF by binding irreversibly to the enzyme

block other enzymes in the pathway

Question 10

what defects odes folate antagonism result in?

Answer 10

neural tube
limbs
oro-facial

Question 11

what sort of problems can neural crest cell destruction cause and what drugs cause this?

Answer 11

retinoids i.e. isotretinoin

aortic arch anomalies
ventricular septal defects
craniofacial malformations
oesophageal atresia
pharyngeal gland abnormalities

Question 12

what damage can NSAIDS cause to foetal development ?

Answer 12

orofacial clefts
cardiac septal defects
premature closing of ductus arteriosus

Question 13

give examples of fetotoxicity complications.

Answer 13

growth retardation structural malformations
foetal death
functional development
carcinogenesis

Question 14

what effects does ACE inhibitors cause?

Answer 14

renal damage

growth restrictions

Question 15

what effects can warfarin cause?

Answer 15

haemorrhage in the feats

malformations in CNS and skeletal system

Question 16

what drugs cause premature closing of ductus arteriosius?

Answer 16

NSAIDS

Question 17

what effect does valproate, carbamazepine and phenytoin cause?

Answer 17

neural tube defect

Question 18

what drugs should you avoid when breast feeding?

Answer 18

cytotoxics
immunosuppressants
anti-convulsants
amiodarone 
lithium
radio-iodine

Question 19

what are the effects of isotretinoin in pregnancy?

Answer 19

aortic arch anomalies
craniofacial anomalies
ventricular septal defects
pharyngeal gland anomalies
oesophageal atresia

Question 20

what is the most critical period in pregnancy when you should avoid all medications if possible?

Answer 20

first 10 weeks

Question 21

is trimethoprim ok to prescribe in pregnancy to treat UTI?

Answer 21

yes but avoid in first trimester

Question 22

if a mother is breast feeding and is requring medication for pain relief, what can she safely take?

Answer 22

paracetamol
ibuprofen (some say not to use it)
codeine (not harmful but mother metabolism is variable so risk of morphine OD in baby)

Question 23

if the mother is epileptic and takes a seizure during pregnancy, what consequence can this have on the baby?

Answer 23

foetal hypoxia

Question 24

what complications can warfarin have on the foetus?

Answer 24

reduces vitamin K levels therefore clotting factors
congenital heart defects
problems with bones
growth restriction

Question 25

what epilepsy medication is used in pregnancy?

Answer 25

lamotrigine

Question 26

does insulin and metformin cross the placenta?

Answer 26

insulin doesn’t

metformin does

Question 27

what are some of the affects that having diabetes can have on the foetus?

Answer 27

macrosomia
still birth
congenital malformation i.e. cardiac