What is Diclegis, and how does it work?

  • Diclegis is a prescription medicine used to treat nausea and vomiting of pregnancy in women who have not improved with change in diet or other non-medicine treatments.
  • It is not known if Diclegis is safe and effective in women with severe nausea and vomiting of pregnancy, a condition called hyperemesis gravidarum. Women with this condition may need to be hospitalized.
  • It is not known if Diclegis is safe and effective in children under 18 years of age.

What are the side effects of Diclegis?

Diclegis may cause serious side effects, including drowsiness.

Drowsiness is a common side effect when taking Diclegis, but can also be severe:

  • Do not drive, operate heavy machinery, or other activities that need your full attention unless your healthcare provider says that you may do so.
  • Do not drink alcohol, or take other central nervous system depressants such as cough and cold medicines, certain pain medicines, and medicines that help you sleep while you take Diclegis. Severe drowsiness can happen or become worse causing falls or accidents.

Diclegis may cause false positive urine drug screening test for methadone, opiates and PCP.
These are not all the possible side effects of Diclegis.

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA1088.

What is the dosage for Diclegis?

Dosage Information

  • Initially, take two Diclegis delayed-release tablets orally at bedtime (Day 1).
  • If this dose adequately controls symptoms the next day, continue taking two tablets daily at bedtime.
  • However, if symptoms persist into the afternoon of Day 2, take the usual dose of two tablets at bedtime that night then take three tablets starting on Day 3(one tablet in the morning and two tablets at bedtime).
  • If these three tablets adequately control symptoms on Day 4, continue taking three tablets daily. Otherwise take four tablets starting on Day 4 (one tablet in the morning, one tablet mid-afternoon and two tablets at bedtime).
  • The maximum recommended dose is four tablets (one in the morning, one in the mid-afternoon and two at bedtime) daily.
  • Take on an empty stomach with a glass of water. Swallow tablets whole. Do not crush, chew, or split Diclegis tablets.
  • Take as a daily prescription and not on an as needed basis. Reassess the woman for continued need for Diclegis as her pregnancy progresses.


13 Early Signs & Symptoms of Pregnancy See Slideshow

What drugs interact with Diclegis?

Drug Interactions

  • Use of Diclegis is contraindicated in women who are taking monoamine oxidase inhibitors (MAOIs), which prolong and intensify the anticholinergic (drying) effects of antihistamines.
  • Concurrent use of alcohol and other CNS depressants (such as hypnotic sedatives and tranquilizers) with Diclegis is not recommended.

Drug-Food Interactions

  • A food-effect study demonstrated that the delay in the onset of action of Diclegis may be further delayed, and a reduction in absorption may occur when tablets are taken with food.
  • Therefore, Diclegis should be taken on an empty stomach with a glass of water.

False Positive Urine Tests For Methadone, Opiates And PCP

  • False positive drug screens for methadone, opiates, and PCP can occur with doxylamine succinate/pyridoxine hydrochloride use.
  • Confirmatory tests, such as Gas Chromatography Mass Spectrometry (GC-MS), should be used to confirm the identity of the substance in the event of a positive immunoassay result.

Is Diclegis safe to use while pregnant or breastfeeding?

  • Diclegis is intended for the treatment of nausea and vomiting of pregnancy in women who do not respond to conservative management.
  • Maternal risks are discussed throughout the labeling. No increased risk for congenital malformations has been reported in epidemiologic studies in pregnant women.
  • Women should not breastfeed while using Diclegis.
  • The molecular weight of doxylamine succinate is low enough that passage into breast milk can be expected.
  • Excitement, irritability and sedation have been reported in nursing infants presumably exposed to doxylamine succinate through breast milk. Infants with apnea or other respiratory syndromes may be particularly vulnerable to the sedative effects of Diclegis resulting in worsening of their apnea or respiratory conditions.
  • Pyridoxine hydrochloride is excreted into breast milk.
  • There have been no reports of adverse events in infants presumably exposed to pyridoxine hydrochloride through breast milk.


The first sign of pregnancy is most often: See Answer

Treatment & Diagnosis

Medications & Supplements

Subscribe to MedicineNet's Pregnancy & Newborns Newsletter

By clicking "Submit," I agree to the MedicineNet Terms and Conditions and Privacy Policy. I also agree to receive emails from MedicineNet and I understand that I may opt out of MedicineNet subscriptions at any time.

Health Solutions From Our Sponsors

FDA Logo

Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

Medically Reviewed on 10/16/2020
All sections courtesy of the U.S. Food and Drug Administration