New report calls into question effectiveness of pregnancy anti-nausea drug

January 17, 2018, St. Michael's Hospital
Previously unpublished information from the clinical trial that the US Food and Drug Administration relied on to approve the most commonly prescribed medicine for nausea in pregnancy indicates the drug is not effective, according to a new report by Dr. Nav Persaud, a researcher and family physician at St. Michael's Hospital in Toronto. Credit: St. Michael's Hospital

Previously unpublished information from the clinical trial that the U.S. Food and Drug Administration relied on to approve the most commonly prescribed medicine for nausea in pregnancy indicates the drug is not effective, a new report says.

Researchers at St. Michael's Hospital obtained thousands of pages of documents from Health Canada relating to the that was reported in 2010 as showing pyridoxine-doxylamine was effective in reducing nausea and vomiting in pregnancy.

The trial found that on a 13-point scale, women who took the drug sold as Diclectin in Canada (Diclegis in the United States) reported symptom reductions that were 0.7 points greater than women who took a placebo.

But Dr. Nav Persaud, a researcher and family physician at St. Michael's, said the manufacturer's detailed 9,000-page "clinical study report" he obtained from Health Canada specified that the findings would be clinically important only if there were a three-point reduction in symptoms.

"That information was hidden until now," he said.

His analysis was published today in the online journal PLOS ONE.

Dr. Persaud said that while the findings reported in 2010 may be statistically significant, they were not large enough to be noticeable by women taking the medication. By the end of the two-week trial, most women given a placebo had little or no symptoms.

Dr. Persaud said there was also "selective reporting" of secondary outcomes in the 2010 publication that made Diclectin appear effective. The 2010 paper indicated apparent benefits of the drug such as a reduction in the time lost from employment due to nausea and vomiting. But the 2010 publication did not include outcomes where there was no difference between the two groups, such as time lost from household tasks or number of visits to health-care providers.

The clinical trial was sponsored by Duchesnay Inc., the manufacturer of the drug. It was conducted at six university medical centres in the United States. The published results were based on 101 women who took pyridoxine-doxylamine and a control group of 86 women; the original enrollment was higher, but many women dropped out during the trial.

Dr. Persaud said that when Duchesnay approached the FDA in the early 2000s to approve pyridoxine-doxylamine, the regulatory agency said it needed evidence from a clinical trial. The FDA approved the drug in 2013, after this trial was done, and it has been prescribed in 33 million women worldwide according to the company. There is at least one prescription filled for every two births in Canada.

In the 1980s, the drug was voluntarily withdrawn from the American market in the midst of legal claims about birth defects that were eventually rejected by courts. Recently, Kim Kardashian was censured by the FDA for inappropriately promoting the drug on social media.

Dr. Persaud said the FDA should revisit its decision, as should Health Canada and provinces that offer the drug through publicly funded prescription drug plans. Clinicians could stop prescribing it and pregnant could seek effective treatments instead of this , he said.

Explore further: Data on effectiveness of morning sickness drug may be flawed

Related Stories

Data on effectiveness of morning sickness drug may be flawed

January 6, 2017
(HealthDay)—Pyridoxine-doxylamine (Diclectin), used to manage the nausea and vomiting associated with morning sickness, may not be as effective as once believed, according to a new analysis published online Jan. 4 in PLOS ...

Unpublished research calls into question efficacy of common morning sickness drug

January 4, 2017
Previously unpublished research calls into question the efficacy of the most commonly prescribed medication for nausea in pregnancy.

Pyridoxine-doxylamine drug safety data lacking

April 16, 2014
(Medical Xpress)—The most commonly prescribed drug for pregnant women suffering from morning sickness in their first trimester does not prevent birth defects even though drug safety data says it does, according to research ...

Are women really under-represented in clinical trials?

January 11, 2018
Several studies have reported a lack of gender diversity in clinical trials, with trials including mostly adult males; however, a recent review of publicly available registration data of clinical trials at the US Food and ...

Effective treatments exist for nausea, vomiting of pregnancy

December 29, 2017
(HealthDay)—Early treatment of nausea and vomiting of pregnancy can prevent complications, according to a Practice Bulletin published online Dec. 21 in Obstetrics & Gynecology.

Are women and minorities adequately represented in new drug testing?

November 7, 2017
A new study to assess the effects of U.S. Food and Drug Administration (FDA) regulations and guidance, intended to encourage greater inclusion of women and minorities in clinical drug trials, has shown appropriate levels ...

Recommended for you

Air pollutants linked to abnormal fetal growth

February 23, 2018
Chinese mothers who were exposed to a high level of certain air pollutants during pregnancy had a higher risk of abnormal fetal growth, according to a new Yale School of Public Health (YSPH) study.

Scientists discover critical molecular biomarkers of preeclampsia

February 21, 2018
Preeclampsia, a sudden pregnancy complication that can interfere with the blood flow to the placenta and possibly to the fetus, can lead to low birth weight, prematurity and even death. It is also a leading cause of maternal ...

Transgender women can breastfeed, first case study shows

February 16, 2018
The first scientific case study has been published describing how a US transgender woman was able to breastfeed her adopted infant by taking hormones that induce lactation.

Controversial pregnancy test drug shows deformities in zebrafish embryos within hours of exposure

February 13, 2018
The components of a controversial drug, allegedly linked to birth defects in the 1960s and '70s, caused deformations to fish embryos just hours after they received a dose in new studies by researchers at the University of ...

Direct link between glands and implanting embryos critical to pregnancy

February 9, 2018
Researchers used 3D imaging with molecular testing to uncover new insight into the earliest stages of mammalian pregnancy—offering clues to unsolved questions in pregnancy.

Lab-grown eggs could pave way towards new fertility treatments

February 8, 2018
Human eggs have been fully grown in a laboratory, in a move that could lead to improved fertility treatments.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.