Pharmacy issues in pregnacy Flashcards
when is the conception date?
may be the day sex occurred or some days later as sperm can live in the body for up to 5 days
when does blastocyst formation occur?
0-16 days after conception
when does organogenesis occur?
17-60 days - cell division, migration, differentiation and cell death
when does histogenesis and functional maturation occur?
61 days until full term
how long is the average pregnancy?
280 days/40 weeks but can get survival at 22 weeks
how long is each trimester?
13/14 weeks
what happens to heart rate and blood pressure when pregnant?
Heart rate increases
Blood pressure decreases
what are physiological changes in the GI tract?
Decreased gastric acid secretion and gastric emptying
what are the physiological renal changes?
decreased bladder capacity and urinary control
what is the role of the placenta?
Has a respiratory function (gas exchange)
Excretory function (maintains water and PH balance)
Resorptive function (like GI tract)
what drugs can pass through the placenta?
lipid soluble drugs with a particularly low molecular weight
what are the three classified groups of degree of placental transfer of drugs?
High: drug crosses rapidly, at equilibrium foetal conc is close to maternal pharmacological concentration
Limited: foetal conc is lower that maternal
Excess: foetal concentration is higher than maternal
what are maternal factors when prescribing?
- implications of not taking
- maternal choice
- gestation (period of pregnancy)
- co-morbities (more than one illness occurring at the same time)
what are foetal factors when prescribing in pregnancy?
- risk of congenital malformations
- risk of organ toxicity
- withdrawal postpartum
what are drug factors to consider when prescribing?
- altered ADME
- Narrow therapeutic index
- safer alternatives
- ability to cross placenta
- topical vs systemic
- adverse effects
what are common ailments seen in pregnancy?
Morning sickness
Haemorrhoids
Indigestion/reflux
UTIs/thrush
Anaemia
Infections
what is the severe form of morning sickness?
hyperemesis gravidarum
- nausea that doesn’t go away, weight loss, reduced appetite, dehydration and feeling faint - risk of starvation and dehydration
what is the treatment of morning sickness?
anti-emetics (POM so should refer to gp)
why may constipation occur in pregnancy?
decrease in motility of smooth muscle due to increase in progesterone
- food passes through GIT more slowly
what laxatives should be avoided in later stages?
stimulant laxatives
- could stimulate labour
why is haemorrhoids more likely in pregnancy?
enlarging uterus exerts pressure, there is an increase in blood volume leading to venous dilation
what can be used to treat thrush
Topical agents eg. clotrimazole
but best to refer to gp - likely to prescribe oral treatment
why are UTIs more likely to occur in pregnancy?
growing foetus can put pressure on the bladder and urinary tract. this traps bacteria or causes urine to leak
DO NOT TREAT OTC - refer (probably gp10 for antibiotics)
what can iron deficiency in pregnancy cause?
anaemia
spontaneous abortion
premature delivery
low birth weight infant
what are common conditions during pregnancy?
- hypertension and pre-eclampsia (placenta moves away from uterus wall)
- gestational diabetes
- venous thromboembolism
