Prescribing in Pregnancy Flashcards
is medicine used commonly in pregnancy
yes
inherent risks during pregnancy (without medication use)
- miscarriage: 15%
- congenital anomalies: 2-3% at birth; 5% at 5 years of age
% of birth defects that medication accounts for
~1%
for a drug to be classified as teratogen, should meet 4 characteristics:
- cause a PATTERN of birth defects
- cause defects dependent on time of exposure
- cause birth defects in a dose dependent manner
- cause defects in genetically susceptible individuals
what do the 4 characteristics suggest that make for the classification of teratogen
=> suggest a biologically plausible mechanism of teratogenicity for a particular drug
define teratogen
- agent or factor that causes malformation of an embryo
[dose response relationship] => teratogenous drug needs to display a dose threshold which means….
- exposures below a certain level do not result in an effect (birth defect)
- dose not always known
what 2 factors are involved in the Dose Response Relationship (a characteristic in teratogens)
- dose threshold
- dose response
[dose response relationship] => teratogenous drug needs to display a dose response which means….
- demonstrated increased effect with increasing dose
[time of exposure] when teratogenous drug exposure in 1st trimester, tend result in _____ because….
- malformations
- because main period of organogenesis in foetus
[time of exposure] when teratogenous drug exposure in 2nd and 3rd trimester, tend result in _____ because….
- growth, neurobehavioural, etc issues
- because this when growth and maturation of organ systems
[timing of exposure] can same drug, giving at different times in pregnancy, have different risks of same and / or different adverse event/s
- yes
- drug has periods of varied susceptibility
[timing of exposure] what abnormalities can retinoids (teratogenic) lead to
isotretinoin embryopathy
- facial dysmorphia (mental health condition)
- cleft palate
- external ear abnormalities
- eye abnormalities
- cardiovascular abnormalities
[timing of exposure] what is exposure window of retinoids
unknown
[timing of exposure] when is exposure window of warfarin
week 6-12
[timing of exposure] dose response in warfarin
worse effects in exposures >5mg
[timing of exposure] what can warfarin (teratogenic) lead to
foetal warfarin syndrome
- nasal hyperplasia
- skeletal abnormalities resulting in short limbs and digits
(note: warfarin - anticoagulant to prevent formation blood clots in legs, lungs, heart, brain; can cause serious bleeding)
[timing of exposure] what can phenytoin (teratogenic) lead to
foetal hydantoin syndrome
- craniofacial dysmorphisms (abnormal body structure)
- digital and nail hyperplasia
- orofacial clefts
- cardiac defects
what is phenytoin used for & is it still used during pregnancy
- seizure control
- important to have adequate seizure control, risk-to-benefit may be necessary to use even though not preferred
what considerations can make a drug still used during pregnancy (outside exposure window)
- risk to benefit
> incl importance of treating condition
> incl if there other, safer options
is the ADEC Categories a reliable resource? why / why not?
- no
why? - simplistic, does not consider: dose, timing, patient, condition, route
- not regularly updated
- confusing categories
what is an issue with Consumer Medicines Information
- patient have access to info
(doc not going to rely on for drug info] - info can be contradictory or conflict with practice
how can you handle patient with conflicting info from Consumer Medicines Information
- communicate discrepancy with patient if they are accessing that sort of information
- letting patient know about practice guideline use of that drug
why is Product Information a less relaible resource
- is company sponsored and so is conservative
