February 19, 2015 — As evidence linking Zofran and birth defects continues to grow, some experts are recommending changes in the way drugs are prescribed for the treatment of morning sickness in pregnant women.
The American Journal of Obstetrics & Gynecology has published an article by Dr. Gideon Koren of the Mortherisk Program, who recommends changes in the way morning sickness is treated:
“Now that a safe and effective drug is available in the United States, there is no reason for women to be exposed to a drug of unproven maternal and fetal safety.”
The “safe and effective” alternative he recommends is pyridoxine-doxylamine, which is essentially Vitamin B6 plus an antihistamine. It has been around since the 1950s, but it was pulled off the market in 1983 over safety concerns. For the next 30 years, there was no FDA-approved drug for morning sickness.
When Zofran was approved in 1991, it quickly became the top-selling drug for morning sickness. This was partly due to marketing of Zofran for pregnant women by GlaxoSmithKline (GSK). Zofran is a “Pregnancy Category B” drug and its fetal safety is unknown.
Prescriptions for Zofran in pregnant women more than doubled from 2008-2013, from 50,000 to 110,000 per month — or around 1 million pregnancies per year. All of these prescriptions are “off-label,” because Zofran is not approved for pregnant women.
In 2013, the FDA re-approved pyridoxine-doxylamine after data on more than 250,000 births found no evidence of fetal risks. It is now marketed under the brand-name Diclegis. It is a “Pregnancy Category A” medication that is specifically approved for the treatment of nausea and vomiting during pregnancy.
GSK is now facing a growing number of lawsuits from pregnant women who had a baby with a birth defect after taking Zofran. They blame GSK for failing to warn about this risk, despite evidence linking Zofran and fetal risks dating back to the 1980s.