An antihistamine used for nausea and vomiting, often in a migraine product
Buclizine
An antihistamine used for nausea and vomiting, often included in a combination product taken for migraine.
What is Buclizine?
Buclizine is an antihistamine that is used to help nausea and vomiting, often as part of a combination product taken for migraine attacks. Like other older antihistamines, it can make you drowsy and can cause antimuscarinic effects such as a dry mouth, blurred vision and constipation. Because of these antimuscarinic effects, it is used with caution in people with glaucoma or prostate (waterworks) problems. It is taken by mouth, and the drowsiness can be added to by alcohol and other sedating medicines.
Education and reference only. This is a plain-language guide to Buclizine — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Buclizine is an older antihistamine that, as well as having antihistamine effects, helps settle nausea (feeling sick) and vomiting (being sick). It is often found as part of a combination product taken for migraine, helping with the sickness that can come with an attack. It is taken by mouth. Like other sedating antihistamines, it commonly causes drowsiness and can have antimuscarinic effects, such as a dry mouth and blurred vision, which is why some people, such as those with glaucoma or prostate problems, need to use it with care.
How it works
Buclizine blocks histamine, and it also acts on the parts of the brain and inner-ear pathways involved in nausea and the sense of balance, which is how it helps settle feeling and being sick. Like other older antihistamines, it crosses into the brain, which is why it tends to cause drowsiness. It also has antimuscarinic activity, meaning it dampens another chemical messenger, which leads to effects such as a dry mouth, blurred vision and constipation, and explains why care is needed in glaucoma and prostate problems. In a migraine product, it is paired with other medicines so it tackles the sickness alongside the headache.
Company & origin
Originated / developed by: Various manufacturers.
An older antihistamine used to help nausea and vomiting, often as part of a combination product taken for migraine.
What it treats
Conditions Buclizine is used for
Practical use
How to take Buclizine
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take it by mouth as directed, often as part of a combination product for migraine.
- Be cautious with driving or concentration, as it commonly causes drowsiness.
- Avoid alcohol while taking it, as it adds to the drowsiness.
- Tell your prescriber if you have glaucoma or prostate (waterworks) problems before using it.
- Check what else is in any combination product you take, so you do not double up on ingredients.
Weighing it up
Advantages & disadvantages of Buclizine
Advantages
- Helps settle nausea and vomiting, including the sickness that can come with migraine.
- Often combined with other medicines so it tackles sickness alongside a headache.
- Taken by mouth.
Disadvantages
- Commonly causes drowsiness, affecting driving and concentration.
- Has antimuscarinic effects such as a dry mouth, blurred vision and constipation.
- Used with caution in glaucoma and prostate (waterworks) problems.
Practical use
Good to know
The main thing to expect with buclizine is drowsiness, so take care with driving or tasks needing concentration, and remember that alcohol and other sedating medicines add to the sleepiness. Being an older antihistamine, it also has antimuscarinic effects, which can cause a dry mouth, blurred vision, constipation and difficulty passing urine. Because of these, it is used with caution in people with glaucoma (raised pressure in the eye) and in men with an enlarged prostate or other waterworks problems, as it can make these worse. Older people can be more sensitive to all these effects. It is frequently part of a combination migraine product, so it is worth knowing what else is in any product you take. As with all antihistamines used for sickness, it eases symptoms rather than treating the underlying cause.
Who should not take it / use with caution
- People who have had a serious allergic reaction to buclizine should not take it.
- It is used with caution in people with glaucoma, as antimuscarinic effects can raise eye pressure.
- It is used with caution in men with an enlarged prostate or other waterworks problems.
- It is used with care in older people, who are more sensitive to its effects.
Monitoring
- Reviewing how well the nausea or migraine sickness is controlled.
- Watching for troublesome drowsiness or antimuscarinic effects, especially in older people.
- Checking it is suitable in people with glaucoma or prostate problems.
Side effects
- Drowsiness, which is the most common effect.
- Antimuscarinic effects such as a dry mouth, blurred vision and constipation.
- Difficulty passing urine, particularly in men with prostate problems.
Key interactions
- Alcohol and other sedating medicines add to the drowsiness.
- Other medicines with antimuscarinic effects add to dry mouth, constipation and urinary problems.
- Tell your prescriber about all your medicines, including anything else taken for sickness.
Available as: Tablets taken by mouth, often within a combination product.
Answers
Buclizine: frequently asked questions
What is buclizine used for?
It is an antihistamine used to help nausea and vomiting, often as part of a combination product taken for migraine attacks.
Will it make me drowsy?
Yes, drowsiness is the most common effect, so take care with driving or concentration and avoid alcohol, which adds to the sleepiness.
What are antimuscarinic effects?
These include a dry mouth, blurred vision, constipation and difficulty passing urine, which is why care is needed in glaucoma and prostate problems.
Can I take it if I have glaucoma or prostate problems?
It is used with caution in these situations because its antimuscarinic effects can make them worse, so tell your prescriber first.
Is it just for migraine?
It helps nausea and vomiting generally but is often included in a combination migraine product to tackle the sickness alongside the headache.
The wider class
About Antihistamine antiemetic
Buclizine belongs to the antihistamine antiemetic class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
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Authoritative sources
- BNF
- NICE CKS
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