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Doxylamine succinate-pyridoxine hydrochloride (Diclectin®)

Last Update: 09 Apr 2025

Welcome to our fact sheet on doxylamine succinate-pyridoxine hydrochloride (Diclectin®) during pregnancy and breastfeeding/ chestfeeding. The information given is based on recent research and may change as science progresses. This content does not replace personalized advice from your healthcare team.

The HEALTHY PREGNANCY HUB team is collaborating with MotherToBaby to share information on this topic. The original version is available here (updated on May 2023). 

Serene, our chatbot, can also answer your questions about medications during pregnancy. 

Please note that this fact sheet is based on United States information and has been adapted for Canada, with a review by our Canadian experts. Minor differences may exist between the two countries. Always consult your healthcare professional for information tailored to your situation. 

1. What is doxylamine succinate-pyridoxine hydrochloride?

The combination of 10 mg of doxylamine succinate and 10 mg of pyridoxine hydrochloride is a medication used to treat nausea and vomiting of pregnancy (NVP), also called “morning sickness.” For more information on NVP, please see the MotherToBaby fact sheet Nausea and Vomiting of Pregnancy here.  

Doxylamine succinate is an antihistamine. Antihistamines lessen the symptoms of allergic reactions and colds and help to treat insomnia (hard time sleeping). Pyridoxine hydrochloride is a form of vitamin B6. 

In the United States, the combination of doxylamine and pyridoxine can be found under the brand name Diclegis® since 2013. In Canada, it can be found under the brand name Diclectin®. Diclegis® and Diclectin® are delayed-release tablets available by prescription. Delayed-release means that the tablet coating prevents the ingredients from being absorbed too quickly by the body. Doxylamine succinate and/or pyridoxine hydrochloride have also been available as over-the-countertooltip medicines/supplements. 

2. What are the risks according to research?

I take doxylamine succinate-pyridoxine hydrochloride. Can it make it harder for me to get pregnant? 

Based on the data available, it is not known if doxylamine succinate-pyridoxine hydrochloride can make it harder to become pregnant. 

Does taking doxylamine succinate-pyridoxine hydrochloride increase the chance of miscarriage?

Miscarriage is common and can occur in any pregnancy for many different reasons. Based on the studies reviewed, doxylamine succinate-pyridoxine hydrochloride does not increase the chance of miscarriage. 

Does taking doxylamine succinate-pyridoxine hydrochloride increase the chance of birth defects?

Every pregnancy starts out with a 3-5% chance of having a birth defect. This is called the background risk. Studies totaling hundreds of thousands of exposed pregnancies have not found that using doxylamine succinate-pyridoxine hydrochloride during pregnancy increases the chance of birth defects. The combination of doxylamine succinate and pyridoxine hydrochloride has been recommended as a first-line treatment for NVP by the American Congress of Obstetricians and Gynecologists (ACOG) and by several medical organizations in Canada for almost 20 years. 

Does taking doxylamine succinate-pyridoxine hydrochloride in pregnancy increase the chance of other pregnancy related problems?

Studies have found that taking doxylamine succinate-pyridoxine hydrochloride  does not increase the chance for pregnancy-related problems such as preterm delivery (birth before week 37) or low birth weight (weighing less than 5 pounds, 8 ounces [2500 grams] at birth). 

Does taking doxylamine succinate-pyridoxine hydrochloride in pregnancy affect future behavior or learning for the child?

Studies that have followed children from ages 2 to 7 years have not found a higher chance of behavior or learning problems in children whose were exposed to doxylamine succinate-pyridoxine hydrochloride during pregnancy. 

3. Breastfeeding/ chestfeeding while taking doxylamine succinate-pyridoxine hydrochloride

There are no formal studies looking at the effects of the combination of doxylamine succinate and pyridoxine hydrochloride on the breastfed/ chestfed infant. 

Antihistamines that can make adults drowsy, such as doxylamine succinate, could cause drowsiness or irritability in a breastfeeding/ chestfeeding infant. Be cautious if you are breastfeeding/ chestfeeding a premature or newborn baby, or a baby who has breathing problems, or if your breastmilk/ human milk supply has not been well established. If you suspect the baby has any symptoms such as drowsiness or poor feeding, contact the child’s healthcare provider. 

Pyridoxine hydrochloride readily enters breastmilk/ human milk; it has not been associated with any problems in breastfeeding/ chestfeeding infants when taken in amounts similar to that present in Diclegis or Diclectin® (10mg). 

According to the manufacturer of Diclegis, individuals prescribed this medication should not breastfeed/ chestfeeding. But, the benefit of using doxylamine succinate-pyridoxine hydrochloride may outweigh possible risks. Your healthcare providers can talk with you about using doxylamine succinate-pyridoxine hydrochloride and what treatment is best for you. Be sure to talk to your healthcare provider about all of your breastfeeding/ chestfeeding questions. 

4. Fathers and sperm donors

If a male takes doxylamine succinate-pyridoxine hydrochloride, could it affect a male’s fertility (ability to get a partner pregnant) or increase the chance of birth defects in a partner’s pregnancy? 

Studies have not been done to see if doxylamine succinate-pyridoxine hydrochloride could affect a male’s fertility or increase the chance of birth defects in a partner’s pregnancy. In general, exposures that males have are unlikely to increase the risks to a pregnancy. For more information, please see the MotherToBaby fact sheet Paternal Exposures here

Key points

  • Doxylamine succinate-pyridoxine hydrochloride (Diclectin®) is a medication that contains an antihistamine (doxylamine) and vitamin B6 (pyridoxine) and is used to treat nausea and vomiting during pregnancy.
  • This medication is recommended as a first line treatment by healthcare professionals in Canada to relieve pregnancy-related nausea.
  • According to studies, doxylamine succinate-pyridoxine hydrochloride does not seem to increase the risk of miscarriage or birth defects or other pregnancy related problems.
  • There are no studies on the combined medication during breastfeeding/ chestfeeding, but doxylamine alone may cause drowsiness in a baby.
  • Always consult your healthcare provider before starting or changing your treatment during pregnancy and breastfeeding/ chestfeeding.

References

Please click here for references. 

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HEALTHY PREGNANCY HUB provides a source of information validated by health professionals; however, this information is provided for informational purposes only and should not replace professional advice. Medical standards and practices evolve as new data becomes available, so it is imperative to consult your doctor or a qualified health professional for any questions or concerns regarding your health without delay or omission. It is the responsibility of your treating physician or any other health professional, based on their independent experience and knowledge of the patient, to determine the best way to evaluate and treat you.

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While consulting symptoms or other medical information on our platform may guide your discussions with your healthcare professional, this information should not be used to make a medical diagnosis or determine treatment. Before making changes to your supplement or medication regimen, please discuss with your medical team or contact 811 (Canada) to ensure the relevance of these changes to your individual situation.

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MotherToBaby
Organization of Teratology Information Specialists (OTIS)
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Émy Roberge
Centre hospitalier universitaire Sainte-Justine
Brigitte Martin
Centre Hospitalier Universitaire Sainte-Justine

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