The question
I'm a new mother and my doctor thinks I am not making enough milk for my baby. He said that I should take a drug called domperidone to boost my milk production. When I googled domperidone, I found that Health Canada put out a warning that says this drug can cause abnormal heart rhythms and sudden death. Is it safe?
The answer
It's certainly true that Health Canada has issued several statements about domperidone in recent years. But whether it's safe for you to take this drug is something you need to discuss with your doctor.
Before you have that conversation, it may be helpful to have some more background. So here goes:
Domperidone was originally approved by Health Canada in 1985 for gastric disorders (such as heartburn) and relieving nausea and vomiting caused by some medications used for Parkinson's disease.
After it had been on the market in several countries for a while, doctors noticed that it had an unexpected side effect – it can stimulate breasts to start producing milk. Breastfeeding advocates immediately recognized that domperidone could be a useful lactation aid.
Although it was never officially approved for this purpose, domperidone started to be prescribed to moms who had trouble producing adequate levels of milk.
Then came the bad news. There were scattered reports, mostly from Europe, linking use of the drug to abnormal heart rhythms – beating too fast, too slow or irregularly – and sudden death. The affected patients tended to be older (60-plus-years-of-age) and they suffered from a variety of other health problems. The cases prompted Health Canada to issue an alert about domperidone in March, 2012.
Some breastfeeding advocates played down the warning, saying the adverse cases weren't really relevant to young healthy nursing mothers. And doctors continued to prescribe the drug on a fairly regular basis.
In January, 2015, after reviewing more data, Health Canada came out with another statement that reiterated the need for caution. It recommended that domperidone should be used only "at the lowest dose for the shortest time." The federal agency also said that patients with heart problems, liver disease or electrolyte disturbances, and those taking certain medications, should not use it.
So, what's the take-home message from these statements?
"Health Canada is not saying you can't use this medication," says Dr. Elizabeth Asztalos, a neonatologist at Sunnybrook Health Sciences Centre. "But it is saying don't go beyond the recommended dose and it should be used with care."
A spokesman for Health Canada, Eric Morrissette, confirmed that doctors are permitted to prescribe whatever drug they feel is appropriate, based on their clinical judgment.
But it's still up to you – the patient – to decide if you want to take it.
First and foremost, you need to be sure you actually have a problem producing enough milk for your child.
"There has got to be a clear determination that the milk supply is a real issue – and not a perceived issue," Asztalos says.
It can be a challenge getting the milk flowing, and proper technique is critically important, she explains. If a baby's position or "latch" on the nipple isn't quite right, then that could be a reason why the infant doesn't seem to be getting enough milk.
Once the baby is suckling, nursing triggers a feedback mechanism in which the mother produces prolactin – a hormone that stimulates the breasts to make milk, Asztalos says.
So, your breastfeeding technique should be assessed before considering a drug option.
If the nursing technique is fine and problems continue, Asztalos says a mother should consider having a blood test to determine whether her prolactin levels are unusually low.
The drug domperidone works by raising the mom's level of the milk-promoting hormone prolactin. If the hormone is already in the normal range for a nursing mom, then taking domperidone "isn't going to make a difference," Asztalos says.
"Adding domperidone to the mix will not be beneficial when you are already at the prolactin threshold needed to make milk. Going higher doesn't mean you are going to make more milk," she explains.
On the other hand, if a new mom's prolactin levels are low, then the drug could help boost her milk production.
Before starting the drug, however, your physician should review your medical history to be sure that you don't have any existing medical conditions – such as a heart ailment – that could be made worse by domperidone, Asztalos says.
You should also be aware of what to expect if you do happen to develop an abnormal heart rhythm as a result of the drug. "You might feel a funny heartbeat, or you missed a beat," Asztalos says. "Things like that need to be watched carefully," and you should seek prompt medical attention if they do happen.
Paul Taylor is a Patient Navigation Advisor at Sunnybrook Health Sciences Centre. He is a former health editor of The Globe and Mail. You can find him on Twitter @epaultaylor and online at Sunnybrook's Your Health Matters.