Prescribing in Pregnancy Flashcards
what should doctors think about when prescribing in pregnancy
Consider non-drug alternatives
(eg. physio instead of NSAIDS, CBT instead of antidepressants)
if benefits outweigh risks, prescribe
how can pregnancy effect pharmacokinetics
- absorption may be effected by morning sickness
- decreased protein binding
- increased plasma volume and fat stores increases volume of distribution
- increased liver metabolism of some drugs
- elimination of renal exerted drugs increases
what are the pharmacodynamic changes seen in pregnancy
no significant changes
what is the period of greatest teratogenic risk
4th - 11th week
avoid drugs if at all possible unless maternal benefit outweighs risk to foetus
what are some common teratogenic drugs
ACEis/ARBs Androgens Antiepileptics Cytotoxics Lithium Methotrexate Retinoids Wardarin
what can be impaired in 2nd and 3rd trimesters
intellectual impairment
behavioural abnormalities
what are some adverse drug effects seen around term
Adverse effects on labour
- progress of labour
- adaptation of foetal circulation
- suppression of foetal systems
- bleeding
adverse effects on baby after delivery
- withdrawal syndrome (opiates, SSRI)
- sedation
what are some delayed effects of teratogens
Diethystillbestrol given to pregnant mothers to prevent miscarriage causes vaginal adenocarcinoma in they’re children aged 15-20
how do you manage chronic conditions in pregnancy
need to discuss risk/benefit balance with patient
-ideally pre-conception
compliance with medication may be poor
- many women avoid taking asthma inhalers in pregnancy
- 20% stop anti epileptic medication in pregnancy
how do you manage epilepsy in pregnancy
avoid valproate (spina bifida and anencephaly) and phenytoin (causes cleft palate)
give folic acid 5mg daily
benefits of treatment outweighs risk in most cases
how do you manage diabetes in pregnancy
insulin thought to be safe
requirements change in pregnancy
poor control increases risk of congenital malformations and intra-uterine death
sulfonylureas are not safe - convert to insulin in pregnancy
how do you manage hypertension in pregnancy
BP falls in 2nd trimester
if need to treat use labetatlol or methyldopa
avoid ACEi/ARB
beta blocker may inhibit foetal growth in late pregnancy
how do you treat nausea and vomiting in pregnancy
Cyclizine is safest
how do you treat UTI in pregnancy
Nitrofurantoin
Cefalexin
(if 3rd trimester - trimethoprim)
how do you treat pain in pregnancy
paracetamol
