IBCLC Pharmacology and Toxicology 2

Question 1

Which resource is considered the gold standard for evaluating medication safety during lactation?

Accepted Answer

LactMed database and Hale's Medications and Mothers' Milk

Answer

The drug manufacturer's package insert

Answer

General drug interaction databases

Answer

Internet search results

Question 2

A breastfeeding mother needs a diagnostic procedure using gadolinium-based contrast for an MRI. What is the recommendation?

Accepted Answer

Breastfeeding can continue without interruption as less than 0.04% of gadolinium is excreted in breast milk

Answer

Stop breastfeeding permanently

Answer

Pump and dump for 48 hours

Answer

Stop breastfeeding for 1 week

Question 3

Which class of antidepressants is generally considered most compatible with breastfeeding?

Accepted Answer

Selective serotonin reuptake inhibitors (SSRIs), particularly sertraline and paroxetine

Answer

Monoamine oxidase inhibitors (MAOIs)

Answer

Tricyclic antidepressants

Answer

Benzodiazepines

Question 4

A mother who is a regular cannabis user asks about the safety of breastfeeding. What should the IBCLC advise?

Accepted Answer

THC is lipophilic, concentrates in breast milk, is stored in infant fat tissue, and may affect neurodevelopment; abstaining is recommended

Answer

Cannabis is safe during breastfeeding

Answer

Cannabis only affects breastfeeding if smoked, not if ingested

Answer

There are no studies on cannabis and breastfeeding

Question 5

What is the relative infant dose (RID) and what threshold is generally considered acceptable?

Accepted Answer

RID is the percentage of the maternal weight-adjusted dose received by the infant through breast milk; less than 10% is generally acceptable

Answer

RID is the actual dose the infant receives; any amount is concerning

Answer

RID is the ratio of drug in milk to drug in maternal blood

Answer

RID measures how quickly a drug is eliminated from breast milk

Question 6

A breastfeeding mother is prescribed radioactive iodine (I-131) for thyroid ablation. What is the correct advice?

Accepted Answer

Breastfeeding must be permanently discontinued for this infant as I-131 concentrates in breast milk and the thyroid of the breastfed infant

Answer

Breastfeeding can continue with no interruption

Answer

Pump and dump for 24 hours then resume

Answer

Wait one week then resume breastfeeding