A bladder antimuscarinic (anticholinergic) for an overactive bladder
Trospium
A bladder-relaxing antimuscarinic that eases the urgency, frequency and leaks of an overactive bladder; it is taken on an empty stomach and commonly causes a dry mouth and constipation.
What is Trospium?
Trospium is a bladder antimuscarinic (anticholinergic) used in the UK to treat an overactive bladder, helping to reduce the sudden urge to pass urine, going too often, and urge leaks. It relaxes the bladder muscle so it can hold more comfortably between visits to the toilet. It is best taken on an empty stomach before food, and the most common nuisance effects are a dry mouth and constipation.
Education and reference only. This is a plain-language guide to Trospium — 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
Trospium is an antimuscarinic (also called anticholinergic) medicine used to treat an overactive bladder. An overactive bladder causes a sudden, hard-to-control urge to pass urine, needing to go very often, getting up at night, and sometimes leaking before reaching the toilet. Trospium calms the bladder muscle so it does not contract as readily, which eases these symptoms. Unlike some similar medicines it does not cross into the brain very easily, which can be helpful in older people who are more sensitive to confusion, although caution is still needed.
How it works
The bladder muscle is told to squeeze by a chemical messenger (acetylcholine) acting on muscarinic receptors. Trospium blocks these receptors, so the bladder muscle relaxes and the urge to empty is reduced. This lets the bladder fill more fully and comfortably before the need to pass urine, which is how it cuts down urgency, frequency and urge leaks. The same blocking action elsewhere in the body explains its typical effects, such as a dry mouth, constipation and blurred vision.
Company & origin
Originated / developed by: Marketed in the UK by several manufacturers under the brand Regurin and as generic trospium chloride..
Trospium is an antimuscarinic developed in Europe and used in the UK to treat the symptoms of an overactive bladder.
What it treats
Conditions Trospium is used for
Practical use
How to take Trospium
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take it on an empty stomach, before food, and swallow whole with water.
- Take it regularly as prescribed rather than only when symptoms flare, as the benefit builds over a few weeks.
- If your mouth feels dry, sip water, chew sugar-free gum and keep up good dental care.
- Eat plenty of fibre and drink enough fluid to ease constipation, but follow any fluid advice you have been given.
- If you miss a dose, skip it and take the next one at the usual time on an empty stomach — do not double up.
- Tell your prescriber if it is not helping after a fair trial, or if side effects are troublesome, rather than stopping without advice.
Weighing it up
Advantages & disadvantages of Trospium
Advantages
- It effectively reduces the urgency, frequency and urge leaks of an overactive bladder.
- It passes into the brain less readily than some other antimuscarinics, which may be helpful in older people sensitive to confusion.
- It is taken by mouth and offers an alternative when bladder-training and lifestyle measures alone are not enough.
Disadvantages
- It must be taken on an empty stomach before food, which is less convenient than medicines that can be taken with meals.
- A dry mouth and constipation are common and can be bothersome.
- Like all antimuscarinics it can blur vision, worsen urinary retention and, in older people, contribute to confusion and falls.
Practical use
Good to know
Trospium is absorbed better on an empty stomach, so it is taken before food rather than with meals. The benefit builds over a few weeks, so it is worth giving it a fair trial. A dry mouth and constipation are the most common nuisances; sipping water, good dental care and keeping well hydrated with plenty of fibre can help. It is reviewed periodically to check it is still needed and still helping, as bladder symptoms can change over time. In older people it is used carefully because antimuscarinics as a group can add to confusion and falls.
Who should not take it / use with caution
- People with untreated narrow-angle (closed-angle) glaucoma.
- People who have difficulty fully emptying the bladder (urinary retention) or a significant blockage to urine flow.
- People with certain bowel problems such as severe constipation, a bowel obstruction, or active conditions like ulcerative colitis or toxic megacolon.
- People with myasthenia gravis (a condition causing muscle weakness), in whom antimuscarinics can worsen symptoms.
- Used with caution in older people, who are more prone to confusion, dry mouth and constipation.
Monitoring
- Review of bladder symptoms to confirm benefit
- Watching for a dry mouth, constipation or difficulty passing urine
- Checking for confusion and falls risk in older people
Side effects
- Dry mouth and constipation are the most common.
- Blurred vision, dry eyes, headache and a faster heartbeat.
- Difficulty passing urine; rarely confusion, especially in older people — report this.
Key interactions
- Other medicines with antimuscarinic (anticholinergic) effects add to the dry mouth, constipation and confusion risk.
- Other medicines for bladder spasm should not usually be combined.
- Tell your pharmacist about all your medicines, as the overall anticholinergic burden matters, particularly in older people.
Available as: Tablets.
Answers
Trospium: frequently asked questions
Why do I have to take trospium on an empty stomach?
Trospium is absorbed better when the stomach is empty, so taking it before food rather than with a meal helps it work properly. Follow the timing your prescriber or pharmacist advises.
How long before trospium starts to help?
Some people notice a difference within a couple of weeks, but the full benefit can take several weeks to build, so it is worth giving it a fair trial before deciding whether it suits you.
Why does it make my mouth so dry?
A dry mouth is the most common effect of bladder antimuscarinics because they reduce some of the body's secretions. Sipping water, chewing sugar-free gum and keeping up good dental care can help; tell your pharmacist if it is troublesome.
Is trospium safe for older people?
It can be used in older people and tends to enter the brain less than some similar medicines, but antimuscarinics as a group can still add to confusion, constipation and falls, so it is used carefully and reviewed regularly.
What is the difference between trospium and Regurin?
They are the same medicine — trospium (or trospium chloride) is the active-ingredient name and Regurin is a brand name. Generic trospium contains the identical active ingredient.
The wider class
About Bladder antimuscarinics
Trospium belongs to the bladder antimuscarinics class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
Browse by body system
Authoritative sources
- BNF: Trospium chloride.
- NICE CKS: Overactive bladder.
- electronic Medicines Compendium (SmPC): Regurin.
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