FDA approves Diclegis for treatment of morning sickness

May 1, 2013

The US Food and Drug Administration (FDA) has approved the drug Diclegis (doxylamine succinate 10 mg, pyridoxine hydrochloride 10 mg) for the treatment of nausea and vomiting of pregnancy (NVP) in women who do not respond to conservative management, including dietary and lifestyle modifications. These modifications include eating several small meals instead of 3 large meals, eating bland foods that are low in fat and easy to digest, and avoiding smells that can trigger nausea.

This is the only treatment for NVP, more commonly known as morning sickness, approved by the FDA in more than 30 years. Diclegis, once called Bendectin, was pulled off the market in 1983 after a safety scare prompted by hundreds of lawsuits claiming birth defects. Although the scare proved to be a false alarm, the Washington Post reported, the manufacturer withdrew the drug because it could not afford to defend itself in court.

“The approval of Diclegis for morning sickness after the lack of an effective and potentially safe therapeutic option for pregnant women in many years serves as another breakthrough in the availability of drugs to this sensitive population,” said Abimbola Farinde, PharmD, MS, clinical staff pharmacist at Clear Lake Regional Medical Center, in Webster, Texas, and an advisor to Contemporary OB/GYN’s sister publication Formulary.

“The re-release of the medication . . . which was largely attributed to more scrutiny being placed on the use of the drug during pregnancy, offers hope to pregnant women who may experience more severe morning sickness and require the use of Diclegis after other steps have failed to achieve relief.”

The FDA granted Diclegis Pregnancy Category A status, which means that the results of controlled studies have not shown an increased risk to an unborn baby during pregnancy. The 2 active ingredients in Diclegis that reduce nausea and vomiting in pregnancy-doxylamine succinate and pyridoxine hydrochloride, or vitamin B6-have been recommended as a first-line pharmacotherapy by American College of Obstetricians and Gynecologists guidelines for the past 9 years.

Diclegis was studied in 261 women experiencing NVP. Study participants in the clinical trial were at least 18 years old and had been pregnant for at least 7 weeks and up to 14 weeks. Women were randomly assigned to receive 2 weeks of treatment with Diclegis or a placebo. The study results showed that women taking Diclegis experienced greater improvement in nausea and vomiting than did those taking placebo. In addition, observational (epidemiological) studies have shown that the combination of active ingredients in Diclegis does not pose an increased risk of harm to the fetus.

Initially, a patient takes 2 Diclegis delayed-release tablets orally at bedtime (day 1). If symptoms persist into the afternoon of day 2, the patient takes the usual dose of 2 tablets at bedtime that night and then adds 1 tablet the following morning on day 3. If symptoms still persist on day 4, the patient takes 1 tablet in the morning, 1 tablet mid-afternoon, and 2 tablets at bedtime. The maximum recommended dose is 4 tablets (1 in the morning, 1 at mid-afternoon, and 2 at bedtime) daily. Diclegis is taken as a daily prescription and not on an as-needed basis to help control symptoms throughout the day.

Drowsiness and sleepiness, which can be severe, are the most common adverse effects reported by women taking Diclegis. Women should avoid using Diclegis when engaging in activities requiring mental alertness, such as driving or operating heavy machinery, until cleared to do so by their physicians.

FDA approves return of treatment for morning sickness, decades after false alarm over safety. Washington Post. April 9, 2013. http://www.washingtonpost.com/national/health-science/fda-approves-return-of-treatment-for-morning-sickness-decades-after-false-alarm-over-safety/2013/04/09/31d8b816-a11f-11e2-bd52-614156372695_story.html. Accessed April 9, 2013.