using duloxetine, mirtazapine, trazodone or venlafaxine during breastfeeding

Last edited 11/2023 and last reviewed 11/2023

Using duloxetine, mirtazapine, trazodone or venlafaxine during breastfeeding

NHS advice states:

• duloxetine, mirtazapine, trazodone and venlafaxine can be used with caution and infant monitoring during breastfeeding, but SSRIs or TCAs are preferred
  
  
• evidence shows that milk levels with duloxetine, mirtazapine, trazodone, and venlafaxine are generally very small to negligible
  • however, there have been a few case reports of higher milk levels with venlafaxine
    
    
• these antidepressants, or their active metabolites, have relatively long half-lives, which could result in accumulation and increased risk of side effects in the infant due to their underdeveloped clearance capacity, particularly in the neonatal period
  • however, in the majority of cases, no infant side effects were reported
    
    
• these antidepressants can cause discontinuation symptoms if stopped abruptly, particularly venlafaxine and duloxetine
  • may make it more difficult to stop treatment, and should be considered when making medicine choices
    
    
• neonatal withdrawal syndrome:
  • infants exposed to duloxetine, mirtazapine, trazodone or venlafaxine during pregnancy should be monitored for withdrawal symptoms. Symptoms may be more severe when exposed to more than one centrally acting medicine
  • symptoms may vary but could include:
    • poor adaptation
    • jitteriness
    • irritability
    • poor gaze
    • agitation
    • hypotonia
    • hypoglycaemia
      • may also manifest as jitteriness/tremors, sweating, irritability, fast breathing, looking pale, and unusual cry
    • gastro-intestinal disturbances
    • respiratory problems and convulsions
    • symptoms typically last for a few days (although symptoms could be delayed or prolonged with mirtazapine due to its extended half-life), but usually resolve without intervention
    • continuing breastfeeding may help relieve withdrawal effects
  • may be difficult to distinguish between neonatal withdrawal symptoms and potential side effects from antidepressant exposure through breast milk
  • if symptoms do not resolve a few days after birth (or longer for mirtazapine), consider that side effects from exposure through breast milk may be a potential cause
    
    
• effect on breastfeeding
  • those taking an antidepressant may have more difficulty breastfeeding, particularly with establishing breastfeeding
  • the underlying condition may contribute to this and additional breastfeeding support may be required

For detailed guidance then see Using duloxetine, mirtazapine, trazodone or venlafaxine during breastfeeding

Notes:

• untreated or inadequately treated depression can have adverse effects on the mother and infant and it is important that the mother receives effective treatment and does not stop taking the antidepressant suddenly
• treatment choice should primarily focus on controlling symptoms with suitability in breastfeeding a secondary consideration
• if duloxetine, mirtazapine, trazodone or venlafaxine have been used successfully during pregnancy, there is no need to switch to a preferred choice in breastfeeding, as long as the infant has been born full term and healthy

1. NHS Specialist Pharmacy Service (November 2023). Using duloxetine, mirtazapine, trazodone or venlafaxine during breastfeeding