A sedating antihistamine for nausea, vomiting and motion sickness
Promethazine teoclate
A sedating antihistamine used for nausea, vomiting and motion sickness.
What is Promethazine teoclate?
Promethazine teoclate is a sedating antihistamine used specifically to prevent and treat nausea, vomiting and motion (travel) sickness. It works on the parts of the brain and inner ear that trigger feeling and being sick. Its main effect is drowsiness, so it is best not to drive or operate machinery after taking it, and it should not be mixed with alcohol. It also has antimuscarinic effects such as dry mouth and blurred vision. It is not suitable for very young children. It is taken by mouth, often before travel for motion sickness.
Education and reference only. This is a plain-language guide to Promethazine teoclate — 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
Promethazine teoclate is a long-established sedating antihistamine. Although antihistamines are often thought of as hay-fever medicines, this one is used mainly for its anti-sickness effect: preventing and treating nausea, vomiting and motion (travel) sickness. The 'teoclate' form is long-acting, which suits its use for journeys. It is taken by mouth as a tablet. Because it makes people drowsy, this is both part of how it helps with travel sickness and its main drawback. It is not recommended for very young children.
How it works
Feeling and being sick are triggered by signals from the inner ear (which senses movement) and from parts of the brain that control vomiting, using chemical messengers including histamine and acetylcholine. Promethazine teoclate blocks these messengers, calming those signals so nausea and vomiting are reduced and motion sickness is prevented. Blocking histamine in the brain is also what makes it sedating, and blocking acetylcholine gives it antimuscarinic effects such as dry mouth and blurred vision. For travel sickness, it is taken before the journey so it is already working when movement starts.
Company & origin
Originated / developed by: Generic (long-established).
A long-established sedating antihistamine used in the UK specifically for nausea, vomiting and motion sickness.
Practical use
How to take Promethazine teoclate
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take it by mouth as directed; for motion sickness, take it before the journey so it is working before movement starts.
- Do not drive or operate machinery until you know how drowsy it makes you.
- Avoid alcohol, which adds to the drowsiness it causes.
- Do not give it to very young children, as it is not suitable for them.
- Tell your prescriber about other medicines and conditions such as glaucoma, prostate problems or epilepsy.
Weighing it up
Advantages & disadvantages of Promethazine teoclate
Advantages
- Effective at preventing and treating nausea, vomiting and motion sickness.
- Long-acting, which suits use for journeys.
- A long-established, well-understood medicine taken by mouth.
Disadvantages
- Commonly causes drowsiness, so it affects driving and using machinery.
- Has antimuscarinic effects such as dry mouth, blurred vision and difficulty passing urine.
- Not suitable for very young children.
Practical use
Good to know
The most important everyday point with promethazine teoclate is that it is sedating: it commonly causes drowsiness, so you should not drive or operate machinery until you know how it affects you, and you should avoid alcohol, which adds to the effect. For motion sickness, it works best taken before the journey rather than once you already feel sick. It also has antimuscarinic effects, such as dry mouth, blurred vision and difficulty passing urine, which can be more troublesome in older people. A key safety point is that it is not suitable for very young children. Tell your prescriber or pharmacist about other medicines, especially sedating ones, and mention conditions such as glaucoma, prostate problems or epilepsy, which can affect whether it is suitable.
Who should not take it / use with caution
- It must not be given to very young children.
- People who have had a serious allergic reaction to promethazine or related antihistamines should not take it.
- It is used with caution in people with glaucoma, prostate problems, epilepsy or significant breathing problems.
Monitoring
- Reviewing how well nausea or motion sickness is controlled.
- Watching for excessive drowsiness and antimuscarinic effects, especially in older people.
- Reviewing whether continued use is needed.
Side effects
- Drowsiness, which is the most common effect.
- Antimuscarinic effects such as dry mouth, blurred vision, constipation or difficulty passing urine.
- Dizziness or, in some people, a feeling of restlessness.
- Rarely, more serious reactions, including, very rarely in young children, breathing problems, which is why it is avoided in them.
Key interactions
- It adds to the drowsiness caused by alcohol, strong painkillers, sleeping tablets and other sedating medicines.
- It can add to the effects of other antimuscarinic medicines, increasing dry mouth and constipation.
- Tell your prescriber about all your medicines so your treatment can be reviewed.
Available as: Tablets taken by mouth.
Answers
Promethazine teoclate: frequently asked questions
What is promethazine teoclate used for?
It is a sedating antihistamine used specifically to prevent and treat nausea, vomiting and motion (travel) sickness.
When should I take it for travel sickness?
Take it before the journey so it is already working when movement starts, rather than waiting until you feel sick.
Will it make me drowsy?
Yes, drowsiness is its most common effect, so do not drive or operate machinery until you know how it affects you, and avoid alcohol.
Can young children take it?
No. It is not suitable for very young children, so it should not be given to them.
Does it have other side effects?
It can cause antimuscarinic effects such as dry mouth, blurred vision and difficulty passing urine, which can be more troublesome in older people.
The wider class
About Sedating antihistamine (for nausea and motion sickness)
Promethazine teoclate belongs to the sedating antihistamine (for nausea and motion sickness) 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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