A provocative new paper questions the efficacy of the morning sickness drug Diclegis
Other experts and the company behind the drug stand by its safety and efficacy
One minute, you have that blissful pregnancy glow, and the next, you’re green with nausea. You’re not alone.
Many moms-to-be are prescribed some type of treatment to ease their morning sickness, from vitamins to medications. Diclegis, also known as Diclectin in Canada, is the only Food and Drug Administration-approved prescription medicine for morning sickness, according to its website. It’s so popular that reality star Kim Kardashian posted a promotional Instagram photo about it in 2015.
Now, a provocative new paper questions the efficacy of the drug.
There were flaws in the 1970s clinical trial that the FDA and the federal department Health Canada used to approve the drug, then known as Bendectin, according to the paper. It was published Wednesday in the journal PLOS One.
The clinical trial, known as the 8-way Bendectin Study, was never published in a scientific journal, said Dr. Nav Persaud, a physician and associate scientist at St. Michael’s Hospital in Toronto and assistant professor at the University of Toronto, who co-authored the new paper.
“I was surprised that there were so many serious problems with a study that forms the basis for approval and prescribing,” he said. “I have stopped prescribing this medication.”
Duchesnay Inc., the Canadian pharmaceutical company behind Diclegis and Diclectin, responded that the medication’s safety and efficacy have been proved in other more recent studies and meta-analyses. Other experts also stand by the drug, and the FDA called it “safe and effective.”
“Based on the available data, the FDA determined that Diclegis has been shown to be safe and effective for the treatment of nausea and vomiting in pregnant women who do not respond to conservative management. The FDA’s determination remains unchanged,” according to a statement emailed by FDA spokeswoman Sarah Peddicord on Wednesday.
“Generally the FDA does not comment on specific studies, but evaluates them as part of the body of evidence to further our understanding about a particular issue and assist in our mission to protect public health. The FDA is reviewing the findings of the paper. The FDA remains committed to informing the public in a timely manner when the agency identifies concerns about approved drug products.”
’This is a flaw’
In the mid-1950s, the combination of doxylamine and pyridoxine was approved by the FDA for the treatment of morning sickness under the name Bendectin. Starting in the late 1970s, a series of lawsuits and studies claimed that the drug was associated with birth defects. The medication was voluntarily withdrawn from the American market in 1983 due to falling sales and rising legal costs.
Then, “this company Duchesnay applied to start selling the same two active ingredients under the name Diclegis,” Persaud said.
In 2013, the FDA approved Diclegis to treat pregnant women experiencing nausea and vomiting.
Persaud and Rujun Zhang, a colleague at the University of Toronto, submitted freedom of information requests to the FDA and Health Canada to obtain data from the 8-way Bendectin Study as part of an initiative to systematically restore and publish old trials, called RIAT.
In their paper, the researchers noted that they selected the trial because it was a critical component in the FDA approval and involved a commonly used drug.
The researchers reviewed about 36,000 pages of information from the FDA, of which about 7,200 were related to the clinical trial. They also obtained 359 pages from Health Canada, but 212 were redacted.