25 January 2018

Popular morning sickness drug might not work

In a study there was a very small difference in the severity of morning sickness between the women who got a placebo and the women who got the drug Diclegis.

One of the more unpleasant aspects of pregnancy is morning sickness, involving nausea and vomiting that can start as early as six weeks, and usually peaks at around the eighth or ninth week.

Now a new report contends that the most commonly prescribed medicine for morning sickness may not work.

FDA should reconsider approval

The drug, Diclegis, failed to meet minimum effectiveness goals in the clinical trial relied upon by the US Food and Drug Administration for its approval in 2013, Canadian researchers reported.

"There was a very small difference between the women who got a placebo and the women who got this medicine," said Dr Nav Persaud, a researcher and family physician at St. Michael's Hospital in Toronto.

The study was published online in the journal PLOS ONE.

Given that, the FDA should reconsider its approval of Diclegis, Persaud said.

Is it effective?

Diclegis is available in South Africa.

The MCC (Medicines Control Council of South Africa) is committed to ensure that all medicines/medical devices/IVDs that are registered are of the required quality, safety and efficacy, and is committed to the consideration of data regarding the any recalls of medicines.

No communication has been issued regarding the withdrawal of Diclegis from the South African market.

"I think medications should only be approved and prescribed if they're proved to be effective," Persaud said. "The very basic question that needs to be answered is if it's effective. If the medication is not effective, it doesn't matter if it's safe or not."

But one of the nation's leading medical associations, the American College of Obstetricians and Gynecologists (ACOG), responded to the new paper with the equivalent of a yawn.

A combination drug

Just this month, ACOG updated its practice guidelines for treating nausea and vomiting during pregnancy, maintaining that Diclegis "is safe and effective and should be considered first-line pharmacotherapy," said Dr Mark Turrentine, chair of ACOG's Practice Bulletin Obstetrics Committee.

"If the US Food and Drug Administration, the authors of the original studies, or the drug manufacturer correct or retract any of the evidence used to develop ACOG's guidance, we will reassess and consider the conclusions at that time," Turrentine said in a statement.

Diclegis is the combination of an antihistamine, doxylamine succinate, with a form of vitamin B6 called pyridoxine hydrochloride.

This combination drug had been available for in the United States starting in the 1950s, but was voluntarily pulled from the market in the 1980s over concerns that it was linked with birth defects.

But lawsuits related to those claims were eventually dismissed, and efforts began in the 2000s to get the drug back onto the US market, Persaud said. The drug has always been available in Canada and is currently sold there as Diclectin.

A previous Health24 article reported on the removal of Diclegis from the market some 30 years ago and its return to favour. 

In 2015 Kim Kardashian got into trouble with the FDA by claiming in an Instagram post that Diclegis is completely safe and carries no risks for the baby. The post was subsequently deleted from her account

Persaud and his colleagues reviewed the 9 000-page clinical study report submitted by the drug's manufacturer, Duchesnay Inc., based in Quebec, Canada. Results of the short two-week trial, which involved 187 women at six US medical centres, were published in 2010.

A 2014 NCBI article confirms the substantial amount of safety data accumulated over the years on Diclegis, making it one of the few drugs that qualify for FDA Pregnancy Category A status

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