Drugs in Pregnancy and Lactation Flashcards
What is the time-frame related risk of drugs in pregnancy?
Conception to 16 days - no risk
17 - 70 days = organogenesis - critical period.
- Major birth defects in organ systems if not careful.
What are some important considerations when prescribing drugs to a pregnant woman?
- Check for pregnancy, ALWAYS, in reproductive age women.
- Balance risk of prescribing vs not prescribing
- Be wary of pharmacokinetic differences in pregnant women. Drug concentrations may need to be monitored.
What are some pharmacokinetic changes that occur in pregnancy?
- Increased total body water and fat
- Altered protein binding (lower albumin)
- Increased liver metabolism
- Increased renal blood flow
E.g. Higher dose required due to increased clearance
E.g. Lower dose required due to decreased protein binding
Which analgesics are confidently safe in pregnancy?
Ideally, use paracetamol (Cat A)
Aspirin is okay too, in low doses.
Which analgesics are mostly safe, but come with risk?
NSAIDs - third trimester may have serious side effects
Opioids - potential for neonatal respiratory depression and withdrawal
Codeine - Okay
All are Cat C.
Are anti-emetics safe to use in pregnancy?
Which should we use?
Most are safe:
- Metoclopramide (Cat A)
- 5-HT3 antagonists (Cat B1)
What are 4 well known safe antibiotics and one risky one?
Safe:
- Penicillin
- Cephalosporins
- Clindamycin
- Metronidazole
Risk:
- aminoglycosides
What are two safe HTN drugs and one that is unsafe
Safe:
- Beta-blockers
- Calcium channel blockers
Very unsafe:
- ACE inhibitors - cause renal failure in neonate
How safe are respiratory drugs?
Almost all are okay
- Continue use of inhaled asthma medication and/or steroids (reasonable dose)
What risks come with diabetic drugs, and what is most recommended?
Risk of macrosomia and neonatal hyperglycaemia.
Insulin is the recommended choice.
What is the difficulty in prescribing psychotropic drugs in pregnancy?
Balance the risks of prescribing with the risks of not prescribing.
Risk of prescribing
- Fetal abnormality/death
Risk of not prescribing
- Fetal abuse / neglect
- Maternal distress, self-harm and use of harmful substitutes
Which anti-psychotics are okay, what should be avoided?
Typical anti-psychotics should be okay
Avoid chlorpromazine and lithium
What is azathioprine? Why is it used, even though it is category D?
Azathioprine is an immunosuppressant drug.
Even though it is category D, it must be used in the case of an organ transplant.
Why is there such little information on drugs in breastfeeding?
Pharmaceutical companies aren’t interetsed, and finding large numbers of women to be studied is diffucult.
Is warfarin safe?
No - can cause fetal loss, intracranial haemorrhage, embryopathy.
Use heparin.
