In its new form, the drug -- formerly called Bendectin and now renamed Diclegis -- is the only medication specifically approved to treat the stomach upset many women suffer from during pregnancy.
In the intervening decades between the drug's withdrawal from the market and its re-approval on Tuesday, the medicine has undergone rigorous scrutiny and is now deemed safe by the FDA.
Obstetricians welcomed the announcement.
"The nausea and vomiting of early pregnancy can range from mild to debilitating," said Dr. Jennifer Wu, an obstetrician-gynecologist at Lenox Hill Hospital in New York City. "Patients will welcome more options for treatment with the reintroduction of Bendectin."
Their nausea may not disappear completely, but "it will hopefully decrease to the point that a patient can function," she added.
Diclegis, which combines vitamin B6 and the antihistamine doxylamine, is a delayed-release pill that's meant to be taken daily before symptoms set in. Those symptoms are often worse after waking up, hence the name "morning sickness." But some women are plagued by nausea all day long.
The medication is intended for women whose nausea isn't "adequately managed through recommended changes in diet and lifestyle," Dr. Hylton Joffe, director of the Division of Reproductive and Urologic Products in the FDA's Center for Drug Evaluation and Research, said in an FDA news release.
Morning sickness usually improves after the first trimester. Recommended dietary and lifestyle changes to help beat the nausea include eating several small meals instead of three large meals, eating low-fat bland foods that are easy to digest and avoiding smells that can trigger episodes.
Another expert said the drug's reintroduction was long overdue.
"This drug should have never been taken off the market in the first place," said Dr. Keith Eddelman, director of obstetrics at Mount Sinai Medical Center in New York City. "It is not a controversial drug and the data is very convincing."
Another drug, Zofran, which is approved for nausea in cancer patients, is widely used for pregnancy, Eddelman said. "I think both of these medications are similar in safety," he added.
Bendectin was widely prescribed after its introduction in 1956, but costly lawsuits claiming safety issues caused the drug's maker, Merrell Dow, to pull it from the market in 1983.
Since then the drug has gone through rigorous testing. For this new approval, the FDA studied Diclegis in 261 women experiencing morning-sickness symptoms related to pregnancy. The women were between seven and 14 weeks of pregnancy and were randomly assigned to receive two weeks of treatment with Diclegis or a placebo, the FDA said.
The researchers found that women taking Diclegis experienced greater symptom relief than those taking placebo and missed fewer days of work.
In other studies, the combination of active ingredients in Diclegis were not found to pose an increased risk of danger to the fetus, the FDA said. However, side effects can include severe drowsiness or sleepiness.
Duchesnay has not yet released a price for Diclegis, the Associated Press reported.
The American College of Obstetricians and Gynecologists has more about morning sickness.