February 27, 2013
Pre-emptive Pyridoxine/Doxylamine More Effective in Severe Morning Sickness

Toronto—Researchers have good news for women nervous about getting pregnant again because of severe morning sickness the first time: Beginning treatment as soon as the pregnancy was discovered resulted in a significant decrease in nausea and vomiting.

The Canadian study out of the Hospital for Sick Children in Toronto was presented at the Society for Maternal-Fetal Medicine’s annual meeting, The Pregnancy Meeting, in San Francisco. Researchers looked at the effectiveness of pre-emptive treatment for hyperemesis gravidarum (HG), which affects 2% of pregnant women, and other forms of severe morning sickness.

Far more serious than normal morning sickness, HG can cause severe dehydration and often results in hospitalization. The recurrence rate is extremely high, 75% to 85% in subsequent pregnancies. (Awareness of the condition has increased because Kate Middleton, wife of Britain’s Prince William, was hospitalized recently for HG.)

Previous treatment for HG was to administer pyridoxine/doxylamine, marketed in Canada as Diclectin, when symptoms appeared, but that often didn’t help, according to the study which divided 59 women with a history of HG or severe morning sickness into two groups.

One group began Diclectin as soon as the pregnancy was discovered, while the second began treatment at the first sign of nausea. The group receiving treatment before the onset of symptoms had a significant decrease in risk of severe nausea and vomiting, the study found.

“This is the first time there is an answer,” said coauthor Gideon Koren, MD. “Women who have experienced hyperemesis are so traumatized by it, they are afraid of a second pregnancy.”

With coauthor Caroline Maltepe, Koren runs a severe morning sickness counseling program at The Hospital for Sick Children. He said he believes Diclectin is safe to take throughout pregnancy or even before conception.

Diclectin is the same formulation as the drug Bendectin, which was marketed in the United States until 1983. It was voluntarily withdrawn by its manufacturer, Merrell Dow Pharmaceuticals, after a series of lawsuits claiming it caused birth defects. For several years, Duchesnay, a Canadian company, has been working toward FDA approval to market Diclectin in the United States. The drug has been used in Canada for more than 30 years.

In a press release, the manufacturer noted that large studies involving more than 200,000 pregnant women and their children refuted the claim of fetal risk, and that American courts rejected all claims of malformations against the drug manufacturer.

In addition, the FDA published a notice in the Federal Register in 1999 that “current evidence supports the conclusion that Bendectin was not withdrawn from the market for reasons of safety or effectiveness.”

“With the very wide maternal-fetal safety record of this drug combination, unmatched by any previous drug on the market, we hope that very soon American women will benefit from a safe and effective drug for morning sickness after 30 years of being orphaned from such medication,” Koren said.

According to the American College of Obstetricians and Gynecologists, “taking Vitamin B6 or Vitamin B6 plus doxylamine is safe and effective and should be considered a first-line treatment” for severe morning sickness—a position supported by the federal Agency for Healthcare Research and Quality.

U.S. Pharmacist Social Connect