How does mirabegron work?
Mirabegron is a type of medicine called a beta-3-adrenergic-receptor agonist.
It works by relaxing the muscles around your bladder. This increases the amount of pee that your bladder can hold and reduces your need to pee as frequently or as urgently.
When will I feel better?
Mirabegron starts to work after about 3 to 4 hours to relax the muscles around your bladder.
However, it can take up to 4 to 8 weeks for you to notice any improvements in your symptoms.
Are there any long-term side effects?
Mirabegron is generally safe to take long term, as long as you're not bothered by side effects.
Many people take it for several months or even years without any problems.
What will happen if I stop taking it?
Do not stop taking mirabegron without talking to your doctor first.
If you stop taking this medicine, it will take about 10 days for it to be completely out of your body.
Your symptoms of an overactive bladder may come back or get worse.
How does mirabegron compare with other medicines for bladder problems?
Mirabegron is not usually the first choice of treatment for an overactive bladder.
Your doctor will usually try you on a type of medicine called an antimuscarinic first.
Antimuscarinics include:
- darifenacin
- fesoterodine
- oxybutynin
- propiverine
- solifenacin
- tolterodine
- trospium
If antimuscarinics are not suitable for you, do not help, or give you side effects, your doctor may want to try you on mirabegron. It works in a slightly different way to antimuscarinics.
Will it affect my contraception?
Mirabegron does not affect any type of contraception, including the combined pill, progestogen-only pill or emergency contraception.
But if mirabegron makes you have severe diarrhoea for more than 24 hours, your contraceptive pills may not protect you from pregnancy. Look on the pill packet to find out what to do.
Find out more:
Can I drive or ride a bike?
Yes, you can usually drive or cycle while taking mirabegron.
However, if you feel dizzy, do not drive, ride a bike or operate machinery until you feel OK again.
It's an offence to drive a car if your ability to drive safely is affected. It's your responsibility to decide if it's safe to drive. If you're in any doubt, do not drive.
Talk to your doctor or pharmacist if you're unsure whether it's safe for you to drive while taking mirabegron. GOV.UK has more information on the law on drugs and driving.
Can I drink alcohol while taking mirabegron?
Drinking alcohol does not affect the way mirabegron works.
However, drinking alcohol can make your symptoms worse, such as needing to pee more often or needing to pee urgently. It can also affect your sleep and make you more likely to have to get up in the night to pee.
Is there any food or drink I need to avoid?
You can eat normally while taking mirabegron.
However, some drinks may irritate your bladder and make your urinary symptoms worse.
These drinks include:
- drinks with caffeine, such as coffee, tea, hot chocolate, cola and energy drinks
- alcohol
- fizzy drinks
- drinks with artificial sweeteners including diet drinks
- citrus fruit juices, such as orange, grapefruit and lime juice
Cutting back on or avoiding these drinks may help your urinary symptoms.
Can lifestyle changes help with an overactive bladder?
There are a number of lifestyle changes that may help your symptoms. It's a good idea to:
- cut back on or avoid drinks that can irritate your bladder, such as drinks containing caffeine
- not drink too much or too little fluid during the day, as this can make incontinence worse
- lose any excess weight if you need to, by eating a healthy diet and exercising regularly
Treatments for urinary incontinence such as bladder training and pelvic floor muscle training can help with your symptoms.
There are also incontinence products to help you manage your symptoms while you're waiting for treatment to start working.
Speak to your doctor if you'd like more information about these treatments or products.