Nav: Home

Unpublished research calls into question efficacy of common morning sickness drug

January 04, 2017

TORONTO, Jan. 4, 2017--Previously unpublished research calls into question the efficacy of the most commonly prescribed medication for nausea in pregnancy.

The now defunct Merrell-National Laboratories conducted a clinical trial in the 1970s to determine whether the drug pyridoxine-doxylamine, sold under the brand name Diclectin, could alleviate morning sickness in the first trimester of pregnancy.

While the results of the trial were never published, Health Canada and the U.S. Food and Drug Administration used the information collected to approve the drug, also known as Bendectin in the United States.

Pyridoxine-doxylamine is so popular that it has been prescribed in 33 million women worldwide and is used in half of Canadian pregnancies that result in live births. The Society of Obstetricians and Gynecologists of Canada lists it as the standard of care for women with nausea and vomiting "since it has the greatest evidence to support its efficacy and safety."

The 40-year-old study was published today in the online journal PLOS ONE by Dr. Nav Persaud, a family physician and researcher at St. Michael's Hospital, as part of the restoring invisible and abandoned trials (RIAT) initiative that holds that unpublished or misreported studies make it difficult to determine the true value of a treatment.

Dr. Persaud said there were many flaws in the study, which may explain why it was never published and which call into question the benefits of Diclectin. He obtained 36,000 pages of documents from the FDA, including the original study report, the protocol and summary results, and other documents from Health Canada, all as the result of freedom of information requests.

The trial was conducted at 14 clinics in the United States and enrolled 2,308 patients in the first 12 weeks of pregnancy who were experiencing nausea and vomiting. The women were randomly assigned to eight groups, one of which received a placebo and the other seven a variety of drugs including the combination for Diclectin. Data from 1,599 participants was analyzed. The proportion of participants who were "evaluated moderate or excellent" was greater in each of the seven groups receiving drugs than those receiving the placebo - 14 per cent for Diclectin.

Dr. Persaud called into questions those conclusions based on what he said were several flaws in the execution and analysis of the trial, including:
  • The final results of the study are not available
  • The high number of participants who did not complete the trial, even though it lasted only one week
  • Outcome data is unavailable for 37 per cent of participants in the placebo arm that was used as the reference for comparisons
  • Data for 30 patients recruited by one of the investigators was excluded on orders of the Commissioner of Food and Drugs in a 1975 letter that referred to "data recording in absence of patient visits."
  • The method by which physicians scored symptoms was not clear

Dr. Persaud said he was unable to contact any of the original researchers and there was evidence that many of them had since died.
-end-
About St. Michael's Hospital

St Michael's Hospital provides compassionate care to all who enter its doors. The hospital also provides outstanding medical education to future health care professionals in 27 academic disciplines. Critical care and trauma, heart disease, neurosurgery, diabetes, cancer care, care of the homeless and global health are among the Hospital's recognized areas of expertise. Through the Keenan Research Centre and the Li Ka Shing International Healthcare Education Centre, which make up the Li Ka Shing Knowledge Institute, research and education at St. Michael's Hospital are recognized and make an impact around the world. Founded in 1892, the hospital is fully affiliated with the University of Toronto.

Media contacts, for more information or to arrange an interview:

Leslie Shepherd, Manager, Media Strategy
St. Michael's Hospital
416-864-6094
shepherdl@smh.ca
Inspired Care. Inspiring Science.
http://www.stmichaelshospital.com

St. Michael's Hospital

Related Placebo Articles:

Methotrexate reduces joint damage progression over placebo in erosive hand OA
According to new research findings presented at the 2019 ACR/ARP Annual Meeting, methotrexate did not demonstrate superior efficacy over placebo for pain relief and function evolution at three and 12 months in patients with erosive hand osteoarthritis, but did significantly reduce the progression of joint damage over placebo and seems to facilitate bone remodeling in these patients.
Botulinum toxin reduces chronic migraine attacks, compared to placebo
A growing body of evidence supports the effectiveness of botulinum toxin injections in reducing the frequency of chronic migraine headaches, concludes an updated review and analysis in the January issue of Plastic and Reconstructive Surgery, the official medical journal of the American Society of Plastic Surgeons (ASPS).
Opioids vs. placebo, nonopioid alternatives for chronic noncancer pain
An estimated 50 million adults in the United States were living with chronic noncancer pain in 2016 and many of them were prescribed opioid medications, even though a clinical benefit is uncertain.
Probiotic no better than placebo for acute gastroenteritis in children
While probiotics are often used to treat acute gastroenteritis (also known as infectious diarrhea) in children, the latest evidence shows no significant differences in outcomes, compared to a placebo.
Most common shoulder operation is no more beneficial than placebo surgery
In a landmark study published this week in the BMJ, Finnish researchers show that one of the most common surgical procedures in the Western world is probably unnecessary.
Omega-3s from fish oil supplements no better than placebo for dry eye
Omega-3 fatty acid supplements taken orally proved no better than placebo at relieving symptoms or signs of dry eye, according to the findings of a well-controlled trial funded by the National Eye Institute (NEI), part of the National Institutes of Health.
Review of Vitamin D Research identifies ethical issues in placebo use
George Washington University's Dr. Leigh Frame reviewed several studies using placebo groups in clinical trials that may pose ethical issues.
Hydroxychloroquine no more effective than placebo for relieving osteoarthritis hand pain
Hydroxychloroquine is no more effective than placebo for relieving moderate to severe hand pain and radiographic osteoarthritis.
Study of heart stents for stable angina highlights potential of placebo effect
Researchers at Imperial College London have explored the placebo effects of a coronary angioplasty procedure with stents for the first time.
Haloperidol as adjunctive therapy superior to placebo for acute gastroparesis symptoms
Haloperidol is an effective first-line agent in combination with standard analgesic and antiemetic agents for the treatment of gastroparesis in the emergency department.
More Placebo News and Placebo Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

In & Out Of Love
We think of love as a mysterious, unknowable force. Something that happens to us. But what if we could control it? This hour, TED speakers on whether we can decide to fall in — and out of — love. Guests include writer Mandy Len Catron, biological anthropologist Helen Fisher, musician Dessa, One Love CEO Katie Hood, and psychologist Guy Winch.
Now Playing: Science for the People

#543 Give a Nerd a Gift
Yup, you guessed it... it's Science for the People's annual holiday episode that helps you figure out what sciency books and gifts to get that special nerd on your list. Or maybe you're looking to build up your reading list for the holiday break and a geeky Christmas sweater to wear to an upcoming party. Returning are pop-science power-readers John Dupuis and Joanne Manaster to dish on the best science books they read this past year. And Rachelle Saunders and Bethany Brookshire squee in delight over some truly delightful science-themed non-book objects for those whose bookshelves are already full. Since...
Now Playing: Radiolab

An Announcement from Radiolab