Drugs in Pregnancy and Lactation

Question 1

Transplacental Drug Transfer

Answer 1

transfer across placenta is bidirectional, placenta is thick early on and around week 5 becomes thinner and increases permeability

Question 2

Characteristics that increase transfer of drugs

Answer 2

high lipiphilicity
low ionization
low maternal protein binding
low molecular weight

Question 3

teratogenic effects and trimester

Answer 3

1st tri-most obvious effects are from 1st tri exposure during organogenesis
2nd or 3rd tri-may cause alterations or damage in fine structure and function
near term or birth may have prolonged action because baby is responsible for metabolism and excretion

Question 4

new fda labeling for pregnancy

Answer 4

Risk summary-risks to developing fetus
Clinical considerations-counseling women
Data- discussion of the data

Question 5

Recommendations for drug selection during pregnancy

Answer 5

long hx of safety, low dose, discourage self medication

Question 6

preconception pharm planning

Answer 6

folic acid ingestion to prevent neural tube defects 0.4-0.8mg for low risk pts

Question 7

Drugs with teratogenic effects

Answer 7

chemotherapeutics
misoprostol
psychoactive
thalidomide

Question 8

tx for depression in pregnancy

Answer 8

cognitive behavioral therapy or interpersonal psychotherapy

Question 9

tx for GM

Answer 9

insulin

Question 10

tx for N/V

Answer 10

BG

Question 11

tx for heartburn

Answer 11

calcium antacids

Question 12

tx for diarrhea

Answer 12

dietary changes

Question 13

tx for constipation

Answer 13

psyllium + water

Question 14

tx for HTN

Answer 14

labetalol

nifedipine

Question 15

tx for infectious disease

Answer 15

PCNs and cephs, erythro and azitrho, nirtofurantoin, gent and tobra

Question 16

tx for sz disorders

Answer 16

AED NO VPA!

Question 17

tx for pain

Answer 17

APAP

Question 18

tx for anticoagulation

Answer 18

LMWH

Question 19

Pharmacokinetic changes in pregnancy

Answer 19

physiologic changes require closer monitoring and dose adjustments with chronic meds

Question 20

SSRI use and pregnancy

Answer 20

Potential risks with use: mainly with paroxetine, congenital malformations, neonatal behavioral syndrome, and persistant pulmonary HTN

Potential risks if untreated: preterm labor and low birth weight

Question 21

Drug use during lactation

Answer 21

breast milk is slightly more acidic than plasma so drugs are weak bases, poorly protein bound, or highly lipid soluble tend to pass into breast milk
lipophilic drugs concentrate in hind milk (last few min of nursing)
milk:plasma ratio indicates the drug passage from maternal plasma to breast milk

Question 22

Lactation considerations and how to minimize exposure

Answer 22

toxicity of drug, dosage and duration, age of infant, quantity of milk consumed
minimize exposure: dose after nursing, use short acting meds, terminate nursing sessions prior to hind milk if lipophilic, choose acidic drugs because they pass poorly through breast milk