Pregnancy Flashcards
(19 cards)
What type of drugs cross placenta
Lipophilic
What is a teratogen
Any agent that causes structural or functional abnormalities in foetus or child after birth due to maternal exposure during pregnancy
What percentage of births are effected by teratogens
2-3%, 1-5% caused by drugs
What are examples of teratogens
Ace inhibitors, sodium valproate, warfarin, methotrexate, hypoglycemics, thalisomide, isotretunoin
What was thalidomide used for and what did it cause in feotus
Used in 1960’s for nausea during pregnancy. caused phocomelia (limb defects)
What is isotretinoin used for and what does it cause in feotus
Resistant acne. Causes miscarriage, brain development abnormalities, cleft palate, ear and eye abnormalities and septum of the heart
Explain the effects of drugs during different stages of pregnancies
Pre embryonic- days 0-17 post conception is the all or nothing effect. Drugs taken here may effect later development
embryonic- days 18-56. critical stage- major organ system development. greatest malformation risk
foetal- weeks 8-38- major maturation, growth and development
term- weeks 38-42- drugs here can effect labour and child after birth.
what are the pk changes in pregnancy
delayed gastric emptying and increase in pH- alters drug bioavailability and delays peak concentrations
incraesed cardiac output- incrased blood flow increases drug elimnation
increased total body water- increased VD of hydrophilic drugs
increased fat- increased VD of liphophilic drugs but decreased elimination
incraesed renal blood flow- increased clearance
decreased plasma albumin- decreaesd protein binding of drugs, increased free fraction of drug / toxicity
altered cytochrome p450 and uct- altered oral bioavailability.
what drugs should be changed in pregnant asthmatics and why?
dont change anything other than only use prenisolone in exacerbations as only 10% crosses placenta
important to control as can lead to HTN and intra-uterine growth retardation or prem birth (asthma attacks common in 2nd and 3rd trimester)
what can uncontrolled diabetes- gestational diabetes cause in pregnancy?
prem birth, pre-eclmpsia, miscarriage/ still birth, macrosomnia (large baby)
what is gestational diabetes, what causes it and how is it treated?
diabetes that first presents in pregnancy. risk if obese, gain weight or have family hx. treated by diet and exercise
what are prescribing considerations for diabetic pregnant women?
increase insulin in 2nd and 3rd trimester, folic acid 5mg until 12 weeks atleast, discontinue statins, use metformin as hypoglyc of choice
what supplements should be tken in pregnancy for both normal or at risk women?
normal- folic acid 400ug daily before conception and until 12 weeks. vitamin D 10ug daily until birth and end of lactation
at risk- folic acid 5mg daily until atleast 12 weeks. also vit d
what is target bp in pregnancy
135/85 mmhg
what are the three different types of HTN in pregnancy
chronic- established at less than 20 weeks or before preg
pregnancy induced- established at more than 20 weeks but no proteinuria
pre-eclampsia- established at more than 20 weeks but with proteinurea
how is pre-eclampsia avoided and treated?
lose dose aspirin after 12 weeks. treated by delivery of baby
what anti HTN drugs are ok in preg?
labetolol- avoid in asthma
methyldopa
how should epileptic patients be treated in preg?
monotherapy- preferably levetericetam or lamotrigine and folic acid 5mg before preg and to atleast 12 weeks. major mcm using carbemazepine or valproate- need preg prevention prpgramme on valproate.
how is depression treated in preg?
ideally dont change meds, but ssris better safety profile. can cause PPHN, PNAS or low birth weight.
dont use paroxetine. increase doses. dont abruptly stop
