IBCLC Pharmacology and Toxicology 3

Question 1

A mother is taking metformin for type 2 diabetes and wants to breastfeed. What does the evidence show?

Accepted Answer

Metformin has very low transfer into breast milk (RID approximately 0.3-0.7%) and is considered compatible with breastfeeding

Answer

Metformin is contraindicated during breastfeeding

Answer

Metformin causes hypoglycemia in all breastfed infants

Answer

Breastfeeding should be delayed for 4 hours after each metformin dose

Question 2

A breastfeeding mother needs general anesthesia for emergency surgery. When can she resume breastfeeding?

Accepted Answer

Once she is awake, alert, and able to safely hold and feed her infant

Answer

After 48 hours

Answer

After 24 hours minimum

Answer

Only after blood tests confirm drug clearance

Question 3

Which herbal galactagogue has the most evidence for increasing milk supply, and what are the safety considerations?

Accepted Answer

Fenugreek has the most published evidence but can cause GI effects, hypoglycemia, and has cross-reactivity with peanut/chickpea allergies

Answer

St. John's Wort with no safety concerns

Answer

Blessed thistle with no known side effects

Answer

All herbal galactagogues are equally effective and safe

Question 4

A mother is prescribed ibuprofen for postpartum pain. What makes this a preferred analgesic during breastfeeding?

Accepted Answer

It has very low transfer (RID approximately 0.1-0.7%), is highly protein-bound, and is well-studied with no reported adverse effects

Answer

It does not transfer into breast milk at all

Answer

It increases milk production as a side effect

Answer

It is only safe for the first week postpartum

Question 5

What is the primary concern regarding codeine use in breastfeeding mothers?

Accepted Answer

Some mothers are ultra-rapid CYP2D6 metabolizers who convert codeine to morphine at dangerously high rates, leading to infant sedation and potentially fatal respiratory depression

Answer

Codeine reduces milk supply

Answer

Codeine always causes constipation in breastfed infants

Answer

Codeine is safe at all doses during breastfeeding

Question 6

A mother who is a heavy coffee drinker (6+ cups daily) notices her breastfed newborn is unusually irritable and has difficulty sleeping. What is the likely connection?

Accepted Answer

Caffeine accumulates in neonates due to their immature metabolism, with a half-life of approximately 97 hours in newborns versus 5 hours in adults

Answer

Coffee has no effect on breast milk

Answer

The baby is reacting to milk proteins, not caffeine

Answer

Caffeine is only present in breast milk for 30 minutes after consumption