Drugs in Pregnancy

Question 1

What is meant by teratogen?

Answer 1

Damaging to foetus

-> especially in first half of pregnancy as this is the most vulnerable and can affect embryogenesis

Question 2

What are some preventable terogens which mothers are advised to avoid?

Answer 2

Alcohol
Tobacco
Recreational drugs

Question 3

What can alcohol in pregnancy cause to happen?

Answer 3

Foetal alcohol syndrome

Question 4

What can smoking in pregnancy cause to happen?

Answer 4

Low birth weight
Preterm birth
Cerebral palsy
Learning difficulties

Question 5

What can use of recreational drugs in pregnancy cause to happen?

Answer 5

Low birth weight
Withdrawal symptoms
Learning and behavioural problems

Question 6

RECAP- pharmocokinetics?

Answer 6

Effect of the body on the drug

Question 7

RECAP- pharmacodynamics?

Answer 7

Effect of the drug on the body

->maybe remember as the body moves, the drug does not, so pharmacodynamics is the effect on the body??

Question 8

What can be given for nausea and vomiting in pregnancy?

Answer 8

Cyclizine- antihistamine
Prochlorperazine- phenothiazine
Doxylamine/oyridoxine combo (Xonvea) also first line

->second line= ondanestron, metoclopramide

Question 9

What can be given for hypertension in pregnancy?

Answer 9

Labetolol
Nifedipine
Methyldopa
Hydralazine

->ACEi and ARBs are teratogenic so need to be changed as soon as pregnancy confirmed

Question 10

What can be given for epilepsy in pregnancy?

Answer 10

Carbamazepibe
Lamotrigine

->always give high dose folic acid

Question 11

What could occur if phenobarbitone is given in pregnancy for epilepsy?

Answer 11

Cardiac malformations

Question 12

What could occur if sodium valproate is given in pregnancy for epilepsy?

Answer 12

Neural tube defect
Facial clefts

Question 13

What is given for gestational diabetes?

Answer 13

Metformin

->also safe for type2 dia in pregnancy, insulin is also safest

Question 14

What should be given for thromboembolism in pregnancy?

Answer 14

Low molecular weight heparin

Question 15

What could occur if warfarin is given in pregnancy for thromboembolism?

Answer 15

Foetal Warfarin syndrome

Question 16

What can be given for management of asthma in pregnancy?

Answer 16

Short-acting beta2 agonists, LABAs, oral and inhaled corticosteroids all safe

->important to have good control of asthma in pregnancy

Question 17

What can be given for headaches/migraines in pregnancy?

Answer 17

Paracetamol
Sumatriptan for acute treatment of migraine
Propanolol- lowest effective dose

->ibuprofen should be avoided in 3rd trimester

Question 18

What are the risks of morphine based medications in pregnancy?

Answer 18

Risk of neonatal respiratory depressionW

Question 19

When are morphine based meds commonly used in pregnancy?

Answer 19

As analgesia for delivery

Question 20

Which morphine based drug should be avoided during lactation?

Answer 20

Codeine- can cause infant opiate toxicity

Question 21

What is the general advice on taking antidepressants and antipsychotics in pregnancy?

Answer 21

Weight the risk vs benefits in treatment

SSRI’s may be indicated if benefits outweigh positives

Question 22

Lithium may be used in pregnancy for antidepressant/antipsychotic purposes but what are the risks?

Answer 22

Cardiac anomaly- Ebstein’s anomaly

Question 23

Diazepam may be used in pregnancy for antidepressant/antipsychotic purposes but what are the risks?

Answer 23

Cleft lip/palate

->old studies

Question 24

Quetiapine may be used in pregnancy for antidepressant/antipsychotic purposes but what are the risks?

Answer 24

Large baby
Poor neonatal adaption syndrome

Question 25

List some antibiotics which are safe in pregnancy.

Answer 25

Penicillin
Macrolide- use only if no alternative
Cephalosporins

Question 26

List some antibiotics which are NOT safe in pregnancy.

Answer 26

-Tetracycline- effects skeletal development
-Sulphonamides- avoid first trimester, folate antagonist
-Aminoglycosides- auditory/vestibular nerve damage, risk greatest with streptomycin

Question 27

Okay to check you were taking that in, which antibiotic is an antagonist to folate and therefore cannot be taken in the first semester of pregnancy?

Answer 27

Sulphonamides

Question 28

Are cancer treatments generally safe in pregnancy?

Answer 28

No- most cytotoxic drugs are teratogenic

Question 29

What can you use before prescribing drugs to ensure they are safe for pregnancy?

Answer 29

BNF

Question 30

What happens to the volume of distribution of drugs in pregnancy?

Answer 30

Increased

->increased plasma volume and fat increases distribution

Question 31

What happens to GFR in pregnancy?

Answer 31

Increases by 50%

->this leads to higher excretion of drugs, higher medication doses may be required

Question 32

Are drugs able to cross the placenta?

Answer 32

Yes, as do alcohol, nicotine and recreational drugs

->nearly all drugs, except those with a high molecular weight e.g. insulin and heparin

Question 33

List some of the factors which increase the chances of the drug crossing the placenta.

Answer 33

Lipid-soluble, unionised drugs
Increased length of exposure
Stage of pregnancy

Question 34

When in the pregnancy is the greatest risk of foetal abnormalities due to teratogenic drugs?

Answer 34

Early pregnancy during organogenesis

Question 35

Fototoxicity?

Answer 35

Drugs which have toxic effects to the foetus

Question 36

When can warfarin cause most damage to the foetus and what could happen?

Answer 36

If given in 2nd or 3rd trimester, can cause intracranial haemorrhage

Question 37

When can NSAIDs cause most damage to the foetus and what could happen?

Answer 37

If given in 3rd trimester, can cause premature closure of ductus arteriosus resulting in neonatal pulmonary hypertension

Question 38

When can beta blockers cause most damage to the foetus and what could happen?

Answer 38

Beta blockers given in late pregnancy may result in neonatal hypoglycaemia