Diclegis, a drug used to treat morning sickness in pregnant women, has now been approved by the U.S. Food and Drug Administration.

The drug is a generic version of a drug called Bendectin which was approved for use in the U.S. in 1956. Benedictin was withdrawn in the country after many women filed lawsuits against the drug, claiming that it had harmed their babies, reports Reuters. The new drug - Diclegis (doxylamine succinate and pyridoxine hydrochloride) - is made by Duchesnay Inc.

The agency said that the drug should be taken daily and on an empty stomach. Ideally, the dose should begin from two tablets a day, which can be increased to four tablets a day if the woman shows no improvement with a lower dose of the treatment.

"Many women experience nausea and vomiting during pregnancy, and sometimes these symptoms are not adequately managed through recommended changes in diet and lifestyle. Diclegis is now the only FDA-approved treatment for nausea and vomiting due to pregnancy, providing a therapeutic option for pregnant women seeking relief from these symptoms," said Hylton V. Joffe, M.D., from the FDA's Center for Drug Evaluation and Research, in a statement.

The efficacy and safety of the drug was tested on 261 women who had morning sickness. Study participants were randomly assigned to receive either a placebo or Diclegis.

Study results showed that the Diclegis group had fewer symptoms of morning sickness than those in the control (placebo) group.

Also, the ingredients in Diclegis were found to be harmless for the fetus.

The most common side-effect of the drug was drowsiness. Pregnant women should avoid taking the drug when doing tasks that require mental alertness such as driving.

Morning sickness is common in pregnant women, with a third of all pregnant women experiencing nausea during the first few months of pregnancy.

The condition can be controlled by making some dietary changes like eating frequently, avoiding foods high in fat, and drinking plenty of fluids, especially those that have ginger, like ginger tea or ginger water.