Pregnancy and breastfeeding Flashcards
What are common drugs taken by women during pregnancy?
POMS, Ps, GSL, illicit drugs, alcohol, smoking
What for can drugs can be prescribed during pregnancy to help?
- Minor ailments; analgesics, antibiotics, migraines
these can help with back pain - drugs for any pregnancy induced disorders such as morning sickness or cravings
- chronic problem drugs; asthma, depression, HIV, epilepsy
Why should drugs for chronic disorders not be stopped?
- The disease may adversely affect the pregnancy and so should remain controlled
- Other drugs, remedies or alcohol may be more toxic
- If not taking drugs for it epilepsy can lead to fatal damage or miscarriage and diabetes can affect uterine growth
What OTC medicines can be used?
- NSAID’s
- small % use antihistamines
- paracetamol
- osmotic laxatives
- alginates
What counselling is needed pre-conception?
- address biomedical/behavioural issues that pose a health risk
- women on prophylactic drugs should be established
- interventions are good for people health and health behaviours should be discussed
- make sure mother can make informed choices for drugs
How can prophylactic drug help during pregnancy and what are some drugs can cause defects?
- certain prophylactic drugs can prevent adverse consequences
- need counselling
- risks should be mentioned to the patient
- Folic Acid ; necessary for proper haematopoiesis and deficiency can lead to the risk of neural tube defects
- Vitamins supplements can cause adverse effects in pregnancy
What risk does Folic Acid have and what are the doses should be taken depending on risk?
- risk of neural tube defect
- normal risk: Folic acid 400mcg daily until week 12
- high risk: 5mg daily
What are the ADME pharmacokinetic effects for pregnancy?
Absorption:
- nausea and vomiting
- increase in gastric pH and gut transit time and decrease in gastric emptying
- increased absorption from IM injections and a change in bioavailability
Distribution
- increase in ECF, Plasma vol., pH, Fat and volume of distribution
- decrease in albumin, conc., and change in drug protein binding
Metabolism
- hepatic blood flow
- N-demethylation and change in drug metabolism
Elimination
- renal blood flow and GFR
- hepatic blood flow and cholestasis and change in drug elimination
when is the critical period of human development and why?
8-12 weeks and this is the period of embryogenesis
- mode of hormones at risk
- organ and limb development occurs in this period
What are teratogens and what do they cause?
A substance, organism, physical agents or deficiency state capable of inducing abnormal structure of function such as
- demise
- behavioural aberrations
- gross structural abnormalities ; heart and limb defects
- functional deficiencies
What’s the definition of teratogenicity? When is there highest risk of teratogenesis?
- teratogenicity is potential for drug to cause foetal malfunctions and affects embryo
- highest risk is 3-8 weeks as this is when organs are developed
- drugs can cause congenital malfunctions
- if exposure to drug with long half-life we dont know what the long term effects are
What risks are there for 2nd/3rd trimester when taking any drugs?
- adverse effects on neonate if given shortly before/during labour e.g. diazepam
- organs have fully formed in these trimesters so drugs can have more effect on growth and functional tissue development
what drugs might not cross placenta?
- all drugs except high molecular weight drugs such as heparin won’t!
What drugs should be avoided in first trimester to avoid teratogen exposure?
- Cytotoxic drugs; multiple defects, abortion, stillbirth
- thalidomide; limb reduction and defects
- lithium; cardiac defects
- retinoids; craniofacial, cardiac and CNS defects
What drugs should be avoided in second and third trimester to avoid teratogen exposure?
- ACE inhibitors/ ARBs; impaired neonatal BP, growth retardation
- NSAIDs/Aspirin; Labour prolongation, haemorrhage
- Opiates and Benzodiazepines; withdrawal symptoms, respiratory depression
- Tetracyclines; discolouration of teeth, inhibits bone growth
