Prescribing in Pregnancy Flashcards
When was Thalidomide being prescribed?
1958 - 1961
What was wrong with Thalidomide?
3,500 deaths in first year of life
>10,000 born with deformities
What is Thalidomide used for now?
Leprosy
Myeloma
What drugs don’t cross the placenta?
large molecular weight e.g. heparin
What drugs cross the placenta more quickly than others?
Small, lipid-soluble drugs
What may effect the absorption of a drug during pregnancy?
Morning sickness
What effects the distribution of a drug in pregnancy?
Increased plasma volume and fat stores
What causes increased free drug amounts during pregnancy?
decreased protein binding
What is Phenytoin assoc. with?
Increased liver metabolism of some drugs
How is elimination of drugs during pregnancy effected?
Increased GFR
Name 2 drugs where it is important to check concentrations and alter doses according during pregnancy and after delivery?
Lithium
Digoxin
When are women more at risk of hypotension when on antihypertensives?
2nd trimester
What doses of Folic acid has benefit?
400mcg daily for 3 months prior and first 3 months of pregnancy
What is common in the first trimester?
Risk of early miscarriage
Organogenesis
When is the greatest teratogenic risk?
4th - 11th week
When should drugs be given during the first trimester?
Only if benefits outweigh the risks
What problems can arise in the 2nd and 3rd trimester?
Intellectual impairment
Behavioural abnormalities
Toxic effects on foetal tissue
What foetal issue can opiates cause?
Respiratory depression
What drug can cause bleeding?
Warfarin
What drugs can cause withdrawal in the foetus?
Opiates
SSRI’s
What drug was thought to be able to prevent miscarriages?
Diethylstilbestrol
What were the effects of Diethylstilbestrol?
Vaginal adenocarcinoma in girls aged 15-20 whose mothers were exposed to it
Urological malignancy in boys
What are seizures associated with in pregnancies?
Lower verbal IQ in child Hypoxia Bradycardia Antenatal death Maternal death
What can antiepileptics cause?
Congenital abnormalities
What drugs should be avoided?
Valproate
Phenytoin
What should be taken?
Folic acid, 5mg daily
Is Insulin safe?
yes
Are Sulfonylureas safe?
No, convert to insulin
What happens to BP in the 2nd trimester?
Lowers
What 3 drugs can treat hypertension in pregnancy?
labetalol
Methydopa
Nifedipine MR
What antihypertensives should be avoided?
ACEi/ARBs
Beta blockers - inhibit foetal growth
What drug can be used for N+V?
Cyclizine
What drugs can be used for UTI’s?
Nitrofurantoin
Cefalexin
Trimethorprim (3rd trimester)
What drug can be used for pain?
Paracetamol
What drug can be used for heartburn?
Antacids
What should all women be assessed for?
Risk of VTE
What should women with a significant risk of VTE receive?
Thrombopropylaxis with LMWH
What are risk factors for VTE?
Obesity Age >35 years Smoking Para >3 Previous CS
What drug for VTE should be avoided and why?
Warfarin.
Early = Teratogenic
Late = Haemorrhage risk
What drugs especially enter the breast milk?
Small molecules
Fat soluble drugs (Lipophilic)
What milk is protein rich?
Foremilk
What has a higher fat content?
Hindmilk
What can Phenobarbitone cause?
Suckling difficulties
What can Amiodarone cause?
Neonatal hypothyroidism
What can cytotoxics cause?
Bone marrow suppression
What can benzodiazepines cause?
Drowsiness
What can Bromocriptine cause?
Suppresses lactation
