Prescribing in Pregnancy

Question 1

Which drugs cross the placenta? Which do so more quickly?

Answer 1

Most drugs do - except large MW drugs (e.g. heparin).

Small, lipid-soluble drugs cross more quickly

Question 2

What might affect absorption in pregnancy?

Answer 2

morning sickness

Question 3

How is volume of distribution affected in pregnancy?

Answer 3

volume of distribution increases due to increased plasma volume and fat stores.

Question 4

How is protein binding affected in pregnancy - what effect does this have?

Answer 4

decreased protein binding - increased free drug.

Question 5

Give an example of a drug which has increased metabolism by the liver during pregnancy.

Answer 5

phenytoin

Question 6

Why is the renal excretion of drugs increased in pregnancy?

Answer 6

GFR increases early in pregnancy.

Question 7

When might a pregnant lady on antihypertensive medication be more sensitive to this drug?

Answer 7

during 2nd trimester

Question 8

What dose of folic acid should a female be on and when should they take it?

Answer 8

400mcg daily for 3 months prior and first 3 months of pregnancy

Question 9

When is the greatest period of teratogenic risk - which trimester & weeks?

Answer 9

1st trimester - 4th-11th week

Question 10

What harmful effects on the foetus does methotrexate have?

Answer 10

skeletal defects

Question 11

What teratogenic effects do androgens have on the foetus?

Answer 11

virilisation of female foetus

Question 12

During which stage of foetal growth is it suggested that intellectual and behavioural abnormalities can occur?

Answer 12

2nd and 3rd trimester

Question 13

Some NSAIDs can have an adverse effect on labour - what is it?

Answer 13

adaptation of foetal circulation - premature closure of ductus arteriosus

Question 14

Which drug would you avoid around term due to fear of bleeding in labour?

Answer 14

warfarin

Question 15

Which drugs can have adverse effects on the baby after delivery, specifically causing withdrawal syndromes?

Answer 15

opiates and SSRIs

Question 16

Which drug causes vaginal adenocarcinoma in the daughters of the mothers who are exposed to the drug?

Answer 16

diethylstilbestrol

Question 17

What signs are associated with frequent seizures during pregnancy?

Answer 17

lower verbal IQ in child
hypoxia
bradycardia
antenatal death
maternal death

Question 18

which anti-epileptic drugs should be avoided in pregnancy?

Answer 18

phenytoin and sodium valproate

Question 19

What dose of folic acid is given to a pregnant lady with epilepsy?

Answer 19

5mg daily

Question 20

Which diabetes drugs are and are not safe during pregnancy?

Answer 20

sulphonylureas not safe and insulin safe

Question 21

Which anti-hypertensive drugs can be used in pregnancy if needed?

Answer 21

labetalol and methyldopa

Question 22

Which anti-hypertensive drug is not licensed for use in pregnancy but can be used 3rd line?

Answer 22

Nifedipine MR

Question 23

Which anti-hypertensive drug which is safe in pregnancy should be avoided in a patient who is at risk of depression?

Answer 23

methyldopa

Question 24

What effect do beta blockers have on a foetus?

Answer 24

inhibit foetal growth in late pregnancy

Question 25

Pregnancy lady presents acutely with nausea & vomiting - safest drug?

Answer 25

cyclizine

Question 26

Pregnant lady in 2nd trimester presents with UTI - antibiotics?

Answer 26

Nitrofurantoin MR 100mg bd or 50mg 4x daily (7 days)

2nd line: cefalexin 500mg tds

Question 27

Pregnant lady presents in 3rd trimester with UTI - antibiotics?

Answer 27

trimethoprim 200mg bd

2nd line: cefalexin 500mg ads

Question 28

What is the general advice for VTE prevention in all women who are pregnant, in labour or in postpartum period?

Answer 28

encouraged to mobilise and be adequately hydrated

Question 29

List some risk factors for VTE in pregnancy.

Answer 29

obesity
>35 y/o
smoking
para >3
previous DVT
Caesarean delivery

Question 30

When would you treat a pregnant lady for thromboprohpylaxis and for how long?

Answer 30

when she has 2 or more risk factors

at delivery and up to 7 days post-partum

Question 31

How do you treat suspected or established DvT or PE in pregnancy?

Answer 31

therapeutic dose LMWH (dose based on early pregnancy body weight)

Question 32

Describe the characteristics of breast milk at different stages/

Answer 32

Foremilk - high protein
Hindmilk - high fat content
Long feeds - high amounts of fat-soluble drugs

Question 33

Give an example of a drug which is actively concentrated in breast milk and what difficulty this causes for the baby.

Answer 33

phenobarbitone - suckling difficulties

Question 34

If amiodarone is concentrated in breast milk, what problem does this result in for the baby?

Answer 34

neonatal hypothyroidism

Question 35

If mother has cytotoxic drugs and is breastfeeding - what does this mean for baby?

Answer 35

bone marrow suppression

Question 36

If mum consumes benzodiazepines and is breastfeeding, what effect will this have on baby?

Answer 36

drowsiness

Question 37

Which drug would you definitely not want to give to a breastfeeding mum? (drug counteracts breastfeeding)

Answer 37

bromocriptine - suppresses lactation

Question 38

Which antibiotic when given during pregnancy or early childhood causes permanent staining of child’s teeth?

Answer 38

tetracyclines - doxycycline

Question 39

Baby with short palpebral fissures, a flat mid face, short nose and thin upper lip is seen by GP. Which drug was mum taking during pregnancy?

Answer 39

alcohol = foetal alcohol syndrome

other assoc. features including low nasal bridge, minor ear anomalies, micrognathia.

Question 40

Which anti-epileptic in particular is associated with cleft lip and palate?

Answer 40

phenytoin

Question 41

Which drug taken during pregnancy can cause vaginal adenocarcinoma in female offspring?

Answer 41

diethylstilbestrol

Question 42

Which anti-epileptic drug is particularly associated with spina bifida and anencephaly?

Answer 42

sodium valproate (neural tube defects)