Prescribing in Pregnancy

Question 1

what was the drug used for morning sickness that caused lots of death and deformities in babies

Answer 1

thalidomide

Question 2

what drugs cross the placenta

Answer 2

most
except large molecular weight heparin

small, lipid soluble cross more quickly

Question 3

how can pharmacokinetics be affected in pregnancy

Answer 3

Absorption may be affected by morning sickness

Increased plasma volume and fat stores
(Volume of distribution increases)

Decreased protein binding
(Increased free drug)

Increased liver metabolism of some drugs
(Phenytoin)

Elimination of renally excreted drugs increases
Increased GFR

Question 4

what drugs should you monitor doses during pregnancy and after delivery

Answer 4

lithium, digoxin

Question 5

name a drug pregnant women are more sensitive to

Answer 5

can get hypotension with antihypertensives in 2nd trimester

Question 6

what drug should be taken pre conception

Answer 6

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

Question 7

what else needs to be done preconception

Answer 7

review drugs of chronic conditions, choose safest options/ decide if treatment necessary

Question 8

what is the period of greatest teratongenic risk

Answer 8

4-11th week in 1st trimester:

risk of miscarriage, organogenesis

Question 9

what is the general rule for prescribing in 1st trimester

Answer 9

Avoid drugs if at all possible unless maternal benefit outweighs risk to foetus

Question 10

name 8 teratogenic drugs

Answer 10

ACE inhibitors/ARB		
Androgens			
Antiepileptics			
Cytotoxics			 
Lithium				 
Methotrexate			 
Retinoids			 
Warfarin

Question 11

what can ACEis/ ARBs cause

Answer 11

Renal hypoplasia

Question 12

what can androgens cause

Answer 12

Virilisation of female foetus

Question 13

what can antieplieptics cause

Answer 13

Cardiac, facial, limb, neural tube defects

Question 14

what can cytotoxics cause

Answer 14

Multiple defects, abortion

Question 15

what can lithium cause

Answer 15

Cardiovascular defects

Question 16

what can methotrexate cause

Answer 16

Skeletal defects

Question 17

what can retinoids cause

Answer 17

Ear, cardiovascular, skeletal defects

Question 18

what can warfarin cause

Answer 18

Limb and facial defects

Question 19

what is at risk in 2nd and 3rd trimester

Answer 19

Growth of foetus
Functional development
-Intellectual impairment
-Behavioural abnormalities
Toxic effects on foetal tissue

Question 20

name a drug that causes developmental disorders due to affecting foetus in 2nd and 3rd trimester

Answer 20

sodium valproate

Question 21

what drug can suppress the foetal resp system during labour

Answer 21

opiates

Question 22

what drugs can cause withdrawal effect on foeuts after birth

Answer 22

opiates, SSRI

Question 23

what does diethylstilbestrol cause

Answer 23

vaginal adenocarcioma in F and urological malignancy in M in patients whose mothers were exposed (delayed effect of the drug)

Question 24

what should be done to prevent VTE in pregnancy

Answer 24

all should be encouraged to stay mobilised and hydrated

those with significant risk factors should receive thromboprophylaxis with LMWH at delivery and up to 7 days post partum

Question 25

what constitutes significant risk of VTE

Answer 25

2 or more risk factors eg obesity, age>35yrs, smoking, para >3, previous DVT, Caesarean delivery

Question 26

how do you treat suspected DVT or PE

Answer 26

theraputic dose LMWH

Question 27

why should you avoid warfarin in pregnancy

Answer 27

teratogenic in early pregnancy | risk of haemorrhage during delivery if given during late pregnancy

Question 28

what drugs enter breast milk

Answer 28

most especially small molecule and fat soluble (lipophilic) drugs

Question 29

how can breast feeding patterns affect amount of drugs in milk

Answer 29

foremilk- protein rich hind milk- higher fat content longer feeds, higher amounts of fat soluble drugs in milk

Question 30

why might drugs in breast milk accumulate in infant

Answer 30

immature metabolism

Question 31

name a drug that is actively concentrated in breast milk

Answer 31

phenobarbitone (causes suckling difficulties)

Question 32

what can amiodarone in breast milk cause

Answer 32

neonatal hypothyroidism

Question 33

what can cytotoxics in breastmilk cause

Answer 33

bone marrow suppression

Question 34

what can benzodiazepines in breastmilk cause

Answer 34

drowsiness

Question 35

what can bromocriptine in pregnancy

Answer 35

can suppress lactation

Question 36

should pregnant women take herbal remedies e.g. st john wort

Answer 36

should avoid - consider why she wants to take them, undiagnosed illness?

Question 37

what hypertension drugs are considered safe in pregnancy

Answer 37

Labetalol or methyldopa

Question 38

what are the golden rules to prescribing in pregnancy

Answer 38

Balance risk vs benefits Treat if necessary Safest drug, lowest effective dose, shortest possible time

Question 39

what antibiotics given in pregnancy can cause staining of teeth and bones

Answer 39

tetracycline- also avoid in children under 12

Question 40

what are the facial features of fetal alcohol syndrome

Answer 40

``` short palpebral fissures flat midface short nose indisctinct philtrum thin upper lip ```

Question 41

when drug is associated with cleft lip and palate

Answer 41

phenytoin

Question 42

what drug when taken in pregnancy causes vaginal adenocarcinoma in female offspring

Answer 42

stilbestrol

Question 43

name 2 neural tube defects caused by valproate

Answer 43

spina bifida and anecephaly