3: Prescribing in pregnancy Flashcards
Which anti-emetic drug, given in the 1960s, causes birth defects?
Thalidomide
What is the rate of miscarriage in the general population?
25% of women will have a miscarriage during their lifetimes
Should pregnant woman not take any drugs?
Need to weigh benefits vs risks
What alternative therapies could you consider instead of prescribing a drug for a pregnant woman?
Physiotherapy
CBT
etc.
Most drugs (are / aren’t) licensed for use in pregnant women.
aren’t licensed
What are the principles of prescribing in pregnancy?
Benefit > Risk
Low dose monotherapy
Consider interactions
Consider breastfeeding
Avoid high risk drugs e.g warfarin
Does warfarin cross the placenta?
Yes
And it’s teratogenic
Does heparin cross the placenta?
No
And it isn’t teratogenic
What common condition in pregnancy may affect the absorption of a drug?
Morning sickness
Women tend to (gain / lose) weight during pregnancy.
gain weight
affecting the drug’s volume of distribution
What doses of folic acid are given to
a) low risk
b) high risk
women before and during pregnancy?
a) 400 micrograms
b) 5 milligrams
Which cholesterol-lowering drugs cause birth defects?
Statins
What are some examples of chronic conditions which women may have before pregnancy?
Asthma
Epilepsy
Cardiovascular disease (e.g high cholesterol, HTN)
Diabetes
Rheumatoid arthritis
During which period is a foetus at greatest risk of harm from drugs?
1st trimester
0 - 12 weeks
At which point in gestation do women usually realise they’re pregnant?
4 weeks
i.e they’ve been taking the teratogenic drug(s) without knowing they’re pregnant
Which teratogenic drugs are used in hypertension and cause renal hypoplasia?
ACE inhibitors
ARBs
Which drug, used in RA, causes birth defects?
Methotrexate
Which drugs, used in severe acne, cause birth defects?
Retinoids
Which drugs cause respiratory depression and sedation in newborns?
Why might they be prescribed?
Opioids
Maternal pain relief
Apart from respiratory depression, what might be seen in newborn babies whose mothers have been taking opioids?
Withdrawal
Pregnancy and its associated symptoms can lower the ___ ___ in epilepsy.
seizure threshold
Which anti-epileptic drugs should be avoided in pregnancy?
Sodium valproate
Phenytoin - terminates status epilepticus
What dose of folic acid should a woman with epilepsy receive during pregnancy?
Why?
5 milligrams
All anti-epileptic drugs have possibility of causing neural tube defects
What percentage of women on anti-epileptics don’t suffer foetal abnormalities?
96%
___ control of diabetes may cause birth defects.
Poor control
Which drug used in diabetes is contraindicated in pregnancy?
Sulphonylureas
so gliclazide
Which drugs, used in adult hypertension, should be avoided in pregnancy?
ACE inhibitors
ARBs
Which drugs are used to treat pregnancy-induced hypertension?
Methyldopa
Labetalol
Nifedipine
ACEIs and ARBs cause what kind of birth defect?
Renal hypoplasia / absence
Which anti-emetic is given first line for morning sickness?
Cyclizine
How is VTE prevented in pregnant women?
Stay mobile
Stay hydrated
If fulfilling risk factors: LMWH e.g dalteparin +/- low dose aspirin
Which anticoagulant drug is contraindicated in pregnancy?
Warfarin
Which anticoagulant drug should be used instead of warfarin in pregnancy?
LMWH e.g dalteparin
Which antibiotic stains the teeth of young children?
Tetracycline
Which anti-epileptic drug causes cleft lip and palate?
Phenytoin
Which anti-epileptic drug is highly associated with spina bifida and anencephaly?
Sodium valproate
What are some examples of cytotoxic drugs used to treat rheumatic diseases?
Azathioprine
Cyclophosphamide
Methotrexate
they’re all teratogenic
Which mood stabiliser is teratogenic?
Lithium
