drug use in pregnancy and lactation Flashcards
GI changes in pregnancy
- -gastric acid secretion?
- -pH?
acid secretion decreases
higher pH
CV changes in pregnancy
- plasma volume?
- Cardiac output?
- plasma albumin?
expands
increases
decreases
renal changes in pregnancy
- renal blood flow?
- GFR?
- effect on drugs??
increases
increases
increased clearance
hepatic changes in preganancy
increased CYP 3A4 and 2D6 activity increased glucuronidation
= increased drug metabolism
thalidomide
phocomelia (flipper arms)
LIMB defects
+ renal/ear/cardiac malformations
Drug categories category A category B category C category D category X category N
• Category A: controlled human studies; no risk
ex: prenatal vitamins/levothyroxine
• Category B: animal studies show no risk OR animal studies show risk but no human risk
ex: penicillin/acetaminophen
• Category C: animal studies show risk and no controlled human studies OR no animal/human studies
• Category D: human risk; benefits might outweigh risks ex: valproic acid can cause open neural tube defects
• Category X: proven risk in humans, animals, or both; risk outweighs benefit
Ex: isoretinoin/misoprostol/warfarin
• Category N: medication has not been classified
valproic acid
an antiseizure drug
impairs folic acid metabolism
causes neural tube defects
ACE inhibitors
renal tubular dysgenesis (class D) o Potters sequence = clubbed feet, pulmonary hypoplasia and cranial anomalies due to oligohydramnios
diabetes as a teratogen
sacral agenesis/caudal regression and SGA (small for gestational age)
isotretinoin (accutane)
acne drug
spontaneous abortion; major CNS, CV, or craniofacial malformations/dysmorphic facies
warfarin/coumadin
1st trimester –>fetal warfarin syndrome
2nd trimester –> mental retardation and blindness
3rd trimester –> hemorrhage and stillbirth
o Critical period = 6-9 weeks; Results are due to tissue micro-hemorrhage
o Key Features: microcephaly, nasal hypoplasia, and stippled vertebrae/femoral epiphyses
DES
diethylstilbestrol (synthetic estrogen)
causes mullerian anomalies (repro tract anomalies) and vaginal clear cell carcinoma
• Metroconidazole (flagyl)
for vaginosis; mutagenic in bacteria/rodents no associated human malformations
• Aminoglycosides
potential for ototoxicity (ear)
• Sulfonamides
competes with bilirubin-binding sites; potential for hyperbilirubinemia
• Quinolones
high affinity for bones/cartilage; arthropathy in children
• Alcohol
o Fetal Alcohol Syndrome (FAS) = no philtrum, midface hypoplasia, low nasal bridge and ears, microcephaly, shortened palpebral fissures
• Illicit Drugs
gastroschisis
o Marijuana
IUGR (intrauterine growth restriction)
good drugs used for prevention of preterm birth
17 OH-progesterone or tocolytics (Mg sulfate, beta-mimetics, indomethacin, Ca-ch blockers)
good drugs used for induction or ripening
Oxytocin and PGE1
treatment of hemorrhage during pregnancy
Oxytocin or Methyl ergonovine (methergine) or PGE1
use for beta methasone
for fetal benefit: pulmonary immaturity, neonatal necrotizing enterocolitis, intracranial hemorrhage
what drug is given to prevent neonatal group B strep infection
penicillins
• Misoprostol (cytotec)
o a synthetic prostaglandin E1 –> used to start labor, induce abortions, prevent/treat stomach ulcers, and treat postpartum bleeding
use in first trimester associated with Mobius Syndrome (cranial nerve 6/7 palsy, limb malformations, craniofacial abnormalities)
o category X –uterine contractions and miscarriage
o teratogenic – skull defects, cranial nerve palsies, facial malformations, and limb defects
two drugs contraindicated for lactating patient
methotrexate and lithium should not be in milk!
