Drugs in pregnancy

Question 1

Describe the effects of alcohol, smoking and drugs on pregnancy

Answer 1

Alcohol: foetal alcohol syndrome
Smoking: Low birth weight, preterm, cerebral palsy, learning difficulties
Marjuana/ectasy/cocaine: low birth weight, withdrawal symptoms, learning & behavioural problems

Question 2

What does pharmocokinetics mean

Answer 2

• What the body does to a drug
• Movement of the drug, through and out of the body
• The time course: absorption, bioavailiability, distribution, metabolism and excretion

Question 3

What does pharmocodynamics mean

Answer 3

What the drug does to the body
Biochemical/physiological/molecular effects of the drugs on the body
Receptor binding/post receptor effect

Normal physiologic changes in pregnancy lead to alteration in the pharmacokinetics of the drug and may affect the pharmacodynamics

Question 4

Effect of Thalidomide on the fetus

Answer 4

Phocomelia isa rare congenital anomaly where the proximal aspect of an extremity is absent with the hand or foot attached directly to the trunk

Question 5

1st and 2nd line for N&V in pregnancy

Answer 5

1st= **Cyclizine **(antihistamine), prochloroperzine (phenothiazine), Doxylamine/pyridozine (combination product)

2nd line= ondansetron, metoclopramine

Question 6

1st line treatment of hypertension in pregnancy

Answer 6

Labetolol, Nifedipine, methyldopa, hydralazine

Question 7

What are some teratogenic medications for treatment of hypertension

Answer 7

ACE inhibitors, angiotensin receptor antagonist – change as soon as pregnancy confirmed
e.g.
ACE: benazipril, rampiril
ARBs: Azilsartan, Candesartan, Eprosartan, Irbesartan, Losartan

Question 8

1st line treatment of epilepsy in pregnancy

Answer 8

Carbamazepine and lamotrigine
+ high dose folic acid

Question 9

What are some teratogenic medications for epilepsy

Answer 9

Phenobarbitone (cardiac malformations)
Sodium valporate (NTD, facial clefts)

Question 10

Medications for diabetes in pregnancy

Answer 10

Insulin- safest
Gesgational/T2DM- Metformin

Question 11

What diabetic drugs must be discontinued in pregnancy

Answer 11

All oral antidiabetic drugs, exceptmetformin hydrochloride, should be discontinued before pregnancy, and substitiuted with insulin therapy

Women with diabetes may be treated withmetformin hydrochloride[unlicensed in T1D] as an adjunct or alternative to insulin in the preconception period and during pregnancy.Metformin hydrochloridecan be continued, orglibenclamideresumed, immediately after birth and during breast-feeding for those with pre-existingType 2 diabetes. All other antidiabetic drugs should be avoided while breast-feeding.

Question 12

Treatment of thromboembolism in prengnacy

Answer 12

Low molecular weight heparin

Question 13

What drug should be avoided in treatment of thromboembolism in pregnancy

Answer 13

Warfarin- fetal warfarin syndrome/fetal embryopathy
- Nasal hypoplasia and skeletal abnormalities, including short limbs and digits, and stippled epiphyses, is a well-recognised complication of first trimester warfarin use in pregnancy
Avoid in 1st and third trimester

Directly-acting anticoagulants (DOACs, e.g. apixaban, dabigatran, edoxaban and rivaroxaban)- manufacturer advises to avoid-animal toxicity

Question 14

What medication is safe to treat asthma in pregnancy

& what medication has potential toxicity

Answer 14

Risk of medication use are lower than risk of untreated asthama
B2 agnonist: albuterol, salbutamol
**Inhaled corticosteroids: **budesonide
Theophyline: potential toxicity
**Systemic corticosteroid: **severe asthma

Question 15

What medications do we use for treatment of migraines

Answer 15

Paracetamol, sumatriptan (acute), Propanolol (lowest effective dose)

Question 16

What migraine medication must we be careful with in pregnancy

Answer 16

Ibruprofen: persistant pulmonary hypertension- avoid in 3rd trimester

Question 17

Are morphine based medications alright to use in pregnancy

Answer 17

No increase in congenital abnormalities
Risk of neonatal respiratory depression and withdrawal
Used as labour analgesia
Avoid codeine during lactation- infant opiate toxicity

Question 18

What antidepressants & antipsychotics are ok to use in pregnancy

Answer 18

SSRI- selective seritonin reuptake inhibitor
Where its benifits outweigh any potential risks

Risks of destabilisation and maternal relapse must be taken into account when considering discontinuing SSRIs

Question 19

What antibiotics are generally safe in prengnacy

Answer 19

Penicllin- if no allergy
Macrolide- azithromycin/erythromycin; use if no alternative
Cephlosporins- generally safe

Question 20

What antibiotics are to be avoided in pregnancy

Answer 20

Tetracycline: effects skeletal development, discoloration of teeth
Sulphonamides: teratogenic; avoid in first trimester, folate anagonist
**Aminoglyclosides: **Auditory or vestibular nerve damage: risk is greatest with streptomycin

Question 21

Are cancer treatments safe to use in pregnancy?

Answer 21

Most cytotoxic drugs are teratogenic
We must exclude pregnancy before starting these medications
Take specialist advice- if need to start or continue treatment in pregnancy

Question 22

What corona virus treatments are safe in pregnancy

Answer 22

Hydroxychloquine- no significant risk
Azithromycin: macrolide antibiotic
Toxilizumab
Lopinavir/ritonavir- protease inhibitors- no suggestion of malformations. Effects on preterm delivery, low birth weight & stillbirth have been described undetermined
Corticosteroids