Pharmaco Kinetics: Flashcards
(19 cards)
How does absorbion change in pregnancy
- due to nausea and vomiting - MOST IMPORTANT WITH DRUGS - may need antiemetics!! / different administration route!!
- delayed gastric emptying
- reduced bowel motility
How does distribution change in pregnancy
- increased circulating volume
- lower serum albumin for drugs to bind with
- increased fat for fat soluble drugs
Which steroid crosses the placenta, what can this help with?
Betamethasone and dexamethasone - crosses and helps with surfactant production
Metabolism changes in pregnancy
- drugs metabolised faster and some more slowly in the liver
- drugs for epilepsy in particular like lamotrigine
Excretion
Renaly excreted drugs excreted faster - due to increased GFR
What may you have to change for drugs in pregnancy
- dose
- delivery method
- change in drug completely
Sources of information in prescribing in pregnancy
Best Use of Medicines in Pregnancy
LactMed (breastfeeding)
Warfarin safe in pregnancy?
NO
- bleeding risk - antenatal stroke
- facial deformities
- bone deformities
Must work out a change for the safest option
Is aspirin used?
Yes
Readily
Helps in placental development
- reduces preeclampsia and growth problems in the foetus
Is low molecular weight heparin used in pregnancy
Yes
Doesn’t cross placenta
Used to treat and prevent DVT and PE
Asthma medicines in pregnancy use?
YES
Benefits outweigh risks
May cause slowed growth but good
Which epilepsy medicine is the most risky in pregnancy?
Sodium Valproate
- need contraception if on it
- risks of maternal death 7x higher with epilepsy
- major structural defects - spinabififa or cleft palate
- possible development
Methotrexate used in pregnancy
NO
Antifolate - folate antagonist
Attacks dividing cells
Wide range of birth defects
NSAIDS in pregnancy used, when used? What complications caused
First trimester may increase risk of miscarriage
After 30 weeks can affect renal function - early closure of ductus arteriosus
Can use between weeks 14 and 29
Which vaccination cannot be given in pregnancy
- live attenuated vaccine MMR
- may damage foetus
What can be given and not given for cystitis in pregnant women
- amoxicillin
- trimethoprim would be avoided in the first trimester as it is a folate agonist, affecting dividing cells, if no good alternative give with high dose folic acid
- DO NOT GIVE gentamicin!!!!!!!!
What can gentamycin cause?
Inner ear damage for foetuses if given in 1st or second trimester
Is cyclophosphamide used in pregnancy? What does it cause and how
- no
- kills cells - cytotoxic
- miscarriage, still birth and birth defects
What vaccines are reccomended in pregnancy?
Whooping cough - passes on immunity to newborn
- flu
- covid
Last two to protect mother
