Does bupropion (Wellbutrin) pass into breast milk and is it safe for a lactating mother to use while breastfeeding?

Does Wellbutrin Affect Breast Milk?

Yes, bupropion (Wellbutrin) does pass into breast milk and can be detected in the serum of breastfed infants, though typically at very low levels—but there have been two case reports of seizures in breastfed infants, so caution and careful infant monitoring are essential. 1, 2, 3

Transfer into Breast Milk

• Bupropion and its active metabolites (hydroxybupropion, erythrohydrobupropion, threohydrobupropion) are present in human milk 3, 4
• The average infant exposure is approximately 2% of the maternal weight-adjusted dose when considering bupropion plus its active metabolites on a molar basis 3, 4
• Infant serum levels are typically very low or sometimes undetectable, despite measurable drug in breast milk 1, 5

Serious Safety Concern: Seizure Risk

The most critical concern is seizure risk in breastfed infants, despite low systemic exposure. 1, 2, 3

• Two postmarketing case reports describe seizures in breastfed infants whose mothers were taking bupropion 1, 3
• One detailed case involved a 6.5-month-old infant who experienced severe emesis and tonic seizure-like symptoms; the infant had detectable bupropion and hydroxybupropion in serum at concentrations below the adult therapeutic range, suggesting infants may have heightened susceptibility to bupropion's epileptogenic effects 6
• The FDA label explicitly notes that "postmarketing reports have described seizures in breastfed infants" though "the relationship of bupropion exposure and these seizures is unclear" 3

Clinical Decision Algorithm

If Bupropion Is Clinically Necessary:

1. Maintain the therapeutic dose that effectively controls maternal depression—do not reduce the dose, as undertreated maternal mental illness carries its own risks 1, 2

2. Implement strict infant monitoring protocol: 1, 2

   • Watch for seizures (the most serious risk)
   • Monitor for vomiting and diarrhea
   • Assess for jitteriness or excessive sedation
   • Verify appropriate weight gain at every visit
   • Track developmental milestones carefully

3. Educate the mother to recognize warning signs requiring immediate medical attention, particularly any seizure activity, excessive sedation, or poor feeding 2

4. Establish a baseline of the infant's normal behavior patterns to detect subtle changes 2

Guideline Recommendations:

• The American Academy of Pediatrics recommends maintaining the therapeutic bupropion dose while breastfeeding, with careful infant monitoring for seizures, vomiting, diarrhea, jitteriness, and sedation 1, 2
• The American College of Obstetricians and Gynecologists notes the rare seizure reports and advises ensuring appropriate infant weight gain and developmental milestones 1

Risk-Benefit Framework

The benefits of treating maternal depression often outweigh the small absolute risk to the infant, but this is not a trivial decision. 1, 5

• Untreated maternal depression carries significant risks for both mother and infant 1
• The absolute risk of seizures appears very low (only 2 case reports in the literature despite widespread use) 1, 3, 6
• However, seizures represent a serious potential adverse outcome that cannot be dismissed, even if rare 2
• The evidence base is limited (approximately 21 documented cases in the literature), so caution is warranted 1, 2

Important Caveats

• Polytherapy increases risk: The seizure case report involved concurrent escitalopram use, which may have contributed through CYP2D6 inhibition by bupropion, potentially increasing drug levels 6
• Infant age matters: Younger infants (especially under 6 months) may be at higher risk due to immature hepatic metabolism and renal clearance 6
• Alternative antidepressants: Most other antidepressants (particularly SSRIs) are generally considered compatible with breastfeeding and may be safer alternatives if bupropion is not specifically required 7

What NOT to Do

• Do not abruptly discontinue bupropion if it is required for maternal daily functioning—untreated depression poses its own risks 1
• Do not "pump and dump"—this will not reduce infant exposure, as drug levels in milk parallel maternal serum levels 4
• Do not reduce the maternal dose below therapeutic levels in an attempt to minimize infant exposure—this compromises maternal treatment without meaningfully reducing risk 1, 2