drug use in pregnancy and lactation

Question 1

GI changes in pregnancy

• -gastric acid secretion?
• -pH?

Answer 1

acid secretion decreases

higher pH

Question 2

CV changes in pregnancy

• plasma volume?
• Cardiac output?
• plasma albumin?

Answer 2

expands
increases
decreases

Question 3

renal changes in pregnancy

• renal blood flow?
• GFR?
• effect on drugs??

Answer 3

increases
increases

increased clearance

Question 4

hepatic changes in preganancy

Answer 4

increased CYP 3A4 and 2D6 activity increased glucuronidation

= increased drug metabolism

Question 5

thalidomide

Answer 5

phocomelia (flipper arms)
LIMB defects

+ renal/ear/cardiac malformations

Question 6

Drug categories
category A
category B
category C
category D
category X
category N

Answer 6

• 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

Question 7

valproic acid

Answer 7

an antiseizure drug
impairs folic acid metabolism
causes neural tube defects

Question 8

ACE inhibitors

Answer 8

renal tubular dysgenesis (class D)
o	Potters sequence = clubbed feet, pulmonary hypoplasia and cranial anomalies due to oligohydramnios

Question 9

diabetes as a teratogen

Answer 9

sacral agenesis/caudal regression and SGA (small for gestational age)

Question 10

isotretinoin (accutane)

Answer 10

acne drug

spontaneous abortion; major CNS, CV, or craniofacial malformations/dysmorphic facies

Question 11

warfarin/coumadin

Answer 11

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

Question 12

DES

Answer 12

diethylstilbestrol (synthetic estrogen)

causes mullerian anomalies (repro tract anomalies) and vaginal clear cell carcinoma

Question 13

• Metroconidazole (flagyl)

Answer 13

for vaginosis; mutagenic in bacteria/rodents  no associated human malformations

Question 14

• Aminoglycosides

Answer 14

potential for ototoxicity (ear)

Question 15

• Sulfonamides

Answer 15

competes with bilirubin-binding sites; potential for hyperbilirubinemia

Question 16

• Quinolones

Answer 16

high affinity for bones/cartilage; arthropathy in children

Question 17

• Alcohol

Answer 17

o Fetal Alcohol Syndrome (FAS) = no philtrum, midface hypoplasia, low nasal bridge and ears, microcephaly, shortened palpebral fissures

Question 18

• Illicit Drugs

Answer 18

gastroschisis

Question 19

o Marijuana

Answer 19

IUGR (intrauterine growth restriction)

Question 20

good drugs used for prevention of preterm birth

Answer 20

17 OH-progesterone or tocolytics (Mg sulfate, beta-mimetics, indomethacin, Ca-ch blockers)

Question 21

good drugs used for induction or ripening

Answer 21

Oxytocin and PGE1

Question 22

treatment of hemorrhage during pregnancy

Answer 22

Oxytocin or Methyl ergonovine (methergine) or PGE1

Question 23

use for beta methasone

Answer 23

for fetal benefit: pulmonary immaturity, neonatal necrotizing enterocolitis, intracranial hemorrhage

Question 24

what drug is given to prevent neonatal group B strep infection

Answer 24

penicillins

Question 25

• Misoprostol (cytotec)

Answer 25

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

Question 26

two drugs contraindicated for lactating patient

Answer 26

methotrexate and lithium should not be in milk!