Domperidone Versus Metoclopramide: Self-Reported Side Effects in a Large Sample of Breastfeeding Mothers Who Used These Medications to Increase Milk Production

Abstract

Introduction: Metoclopramide and domperidone are medications that block dopamine receptors on the lactotrophs, allowing prolactin levels to rise. Both medications are prescribed to boost milk production in mothers with low milk production due to hypoprolactinemia. The Food and Drug Administration has not approved the use of domperidone in the U.S. because of concerns about increased risk of cardiac arrhythmias. Metoclopramide is often recommended instead. Unfortunately, metoclopramide affects the central nervous system (CNS) and increases the risk of both depression and tardive dyskinesia (TD).Method: The present study is an online survey of self-reported side effects of 1,990 mothers, representing 25 countries, who took metoclopramide, domperidone, or both medications to enhance milk production. Data were collected in 2010.Results: The results indicated that side effects, in general, affected only a small percentage of women who took either medication. Women were 3.6 times more likely to report no side effects when taking domperidone vs. metoclopramide. There were no significant differences in cardiac arrhythmias for women who took metoclopramide versus domperidone. Racing heart was more common with metoclopramide. Less than 1% reported these symptoms in both groups. However, CNS effects were significantly more common in women who took metoclopramide. Risk of depression increased by seven times, and symptoms of TD (tremors, involuntary grimaces, and jerking) increased by 4 to 19 times when women took metoclopramide.Discussion: The results of the present study are preliminary, but suggest that cardiac arrhythmias are a rare side effect with both medications. The CNS side effects with metoclopramide are more concerning, particularly depression and TD. It is hoped that the recommendations regarding the relative safety of these medications will be re-examined in light of these findings.