doxylamine succinate + pyridoxine hydrochloride at a glance
Medicine class
First-generation antihistamine combined with vitamin B6
Usual role
Pregnancy sickness not controlled by lifestyle and dietary measures
Taking the tablets
Take on an empty stomach with water and swallow whole
Alertness
May cause marked sleepiness; avoid driving or hazardous activities until cleared by the prescriber
What is doxylamine succinate + pyridoxine hydrochloride used for?
The selected product is licensed for:
Nausea and vomiting of pregnancy in pregnant adults aged 18 years and over who have not responded to lifestyle and dietary changes.
Severe pregnancy sickness or hyperemesis gravidarum requires specialist management because evidence for this combination is limited.
How does doxylamine succinate + pyridoxine hydrochloride work?
Doxylamine enters the brain and blocks histamine H1 receptors, contributing to anti-sickness effects. Pyridoxine is converted into active vitamin B6 metabolites that also have anti-sickness activity. The precise mechanism in pregnancy sickness is not fully established.
doxylamine succinate + pyridoxine hydrochloride preparations and strengths
Gastro-resistant tablet
Route: Oral
Strengths: 10 mg + 10 mg
How to take doxylamine succinate + pyridoxine hydrochloride
Follow the prescriber’s instructions.
Take on an empty stomach with a glass of water.
Swallow gastro-resistant tablets whole; do not crush, split or chew them.
Tell the prescriber or pharmacist if swallowing the tablet whole is difficult.
Do not stop treatment without discussing it with the prescriber because symptoms may return.
doxylamine succinate + pyridoxine hydrochloride side effects
Common or expected effects
- Very common: sleepiness.
- Common: dizziness, tiredness and dry mouth.
- Other reported effects include headache, blurred vision, constipation, diarrhoea, sweating, rash and difficulty passing urine.
Get urgent medical advice
- Seek urgent help for an allergic reaction or difficulty breathing.
- Obtain urgent assessment for inability to pass urine, severe confusion, fainting, a markedly fast heartbeat or chest discomfort.
- Seizures, severe muscle pain or weakness, and sudden kidney problems can indicate overdose and require emergency care.
doxylamine succinate + pyridoxine hydrochloride in pregnancy
This combination is intended for use during pregnancy. Large observational datasets and UK pregnancy information do not indicate an increased risk of birth defects. Exposure alone does not usually require additional fetal monitoring beyond routine antenatal care.
doxylamine succinate + pyridoxine hydrochloride while breastfeeding
Doxylamine is expected to pass into breast milk and may cause sedation, irritability or excitement in the infant. Infants with apnoea or respiratory disorders may be particularly vulnerable. The prescriber should help decide whether breastfeeding or treatment should be discontinued, considering their respective benefits.
doxylamine succinate + pyridoxine hydrochloride interactions
Important interactions include:
Monoamine oxidase inhibitors
Concomitant use is contraindicated because antihistamine anticholinergic effects may be intensified and prolonged.
Alcohol and other central nervous system depressants
Alcohol, sedatives, tranquillisers, sleeping preparations and some pain or cough-and-cold medicines can cause severe additional drowsiness.
Food
Food can delay onset and reduce absorption, so tablets should be taken on an empty stomach.
Common questions about doxylamine succinate + pyridoxine hydrochloride
Answers are fully visible for fast scanning and source review.
What is it used for?
It treats nausea and vomiting of pregnancy in adults when lifestyle and dietary measures have not worked.
Can it treat hyperemesis gravidarum?
Evidence in hyperemesis gravidarum is limited, so severe pregnancy sickness should be managed by a specialist.
Should it be taken with food?
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.