Always follow the instructions from a pharmacist or doctor, or the leaflet that comes with your medicine.
Dosage and strength of standard tablets
Standard oxybutynin tablets come in strengths of 2.5mg or 5mg.
The usual starting dose for adults and children aged 12 years old and over is 5mg taken 2 or 3 times a day. This may increase to a maximum of 5mg, taken 4 times a day.
The dose will usually be lower for adults over 65.
The usual starting dose for children aged 5 to 11 years old is 2.5mg taken 2 or 3 times a day. This may increase to 5mg taken 2 to 3 times a day.
If you take it twice a day, take it in the morning and evening, 12 hours apart. If you take it 3 or 4 times a day, space the doses evenly throughout the day. For example if you take it 3 times a day, you could take it first thing in the morning, in the middle of the afternoon and at bedtime.
Dosage and strength of slow-release tablets
Slow-release tablets come in strengths of 5mg or 10mg. The usual starting dose for adults and children aged 5 years old and over is 5mg once a day.
Dosage and strength of liquid
Oxybutynin is available as a liquid for children and people who find it difficult to swallow tablets. It comes in 2 strengths:
- 2.5mg of oxybutynin in a 5ml spoonful
- 5mg of oxybutynin in a 5ml spoonful
The usual starting dose for adults and children aged 12 years old and over is 5mg, taken either 2 or 3 times a day.
The dose will usually be lower for adults over 65.
The usual starting dose for children aged 5 to 11 years old is 2.5mg taken 2 or 3 times a day.
If you take it twice a day, take it in the morning and evening, 12 hours apart. If you take it 3 or 4 times a day, space the doses evenly throughout the day. For example, if you take it 3 times a day, you could take it first thing in the morning, in the middle of the afternoon and at bedtime.
Dosage and strength of patches
Oxybutynin is available as a patch that you put onto your skin. The usual starting dose for adults is one 3.9mg patch applied twice a week (every 3 to 4 days).
Changes to your dose
Your doctor may increase your dose depending on how the medicine works for you.
How to take oxybutynin
You can take oxybutynin with or without food.
How to take standard tablets
Swallow the tablets whole with a drink of water.
How to take slow-release tablets
Slow-release tablets release oxybutynin slowly and evenly throughout the day.
Swallow these tablets whole with a drink of water. Do not break, crush or chew them.
Try to take your tablet at the same time each day. This will help you to remember to take it.
Part of the tablet can pass through your body and you might see it in your poo. Do not worry, this is normal and does not affect the way the medicine works.
How to take liquid
If you're giving this medicine to a child to help stop them wetting the bed, give the last dose just before bedtime.
Oxybutynin liquid will come with a plastic syringe or spoon to help you measure out the right dose. If you do not have one, ask your pharmacist for one. Do not use a kitchen teaspoon as it will not measure the right amount of medicine.
How to use patches
Oxybutynin patches are applied twice a week.
You stick them to your skin like a plaster.
- Follow the instructions that come with the patches.
- Remove the old patch before putting on the new one.
- Put a patch on clean, dry skin on your stomach, hip or bottom twice a week (every 3 or 4 days).
- Change the patch on the same 2 days every week, such as every Sunday and Wednesday, or every Monday and Thursday.
- Put the new patch on a different area of your stomach, hips or bottom. Do not put another patch in the same place for at least a week as it may irritate your skin.
How long to take it for
Usually, you'll need to take oxybutynin for a long time.
After 4 weeks your doctor will check that oxybutynin is helping your symptoms. They'll also do a review every 6 to 12 months after that to check it's still working for you.
Take oxybutynin until your doctor tells you to stop. Do not stop taking it just because you feel better.
If you forget to take it
If you forget to take a dose, take it as soon as you remember, unless it's almost time for your next dose. In this case, just skip the missed dose and take your next dose at the usual time.
Never take 2 doses at the same time. Never take an extra dose to make up for a forgotten one.
If you often forget doses, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to help you remember to take your medicine.
If you take too much
Taking more than your prescribed dose of oxybutynin can be dangerous. It can cause symptoms including:
- seeing or hearing things that are not there (hallucinations)
- feeling very restless or excited
- dilated pupils in your eyes
- being unable to pee
The amount of oxybutynin that can lead to an overdose varies from person to person.
Immediate action required: Call 999 if:
You've taken more than your usual dose of oxybutynin and you:
- have a fast or irregular heartbeat
- have breathing problems
- have any loss of movement or are unable to move any part of your body
- are feeling very drowsy or have passed out (lost consciousness)
- feel you're overheating and not sweating normally when you're somewhere hot or when you have a high temperature
Urgent advice: Contact 111 for advice now if:
- you've taken more than your prescribed dose of oxybutynin, even if you do not have symptoms
Call 111 or get help from 111 online.
If you need to go to A&E, do not drive. Ask someone to drive you or call 999 and ask for an ambulance.
Bring the oxybutynin packet or leaflet inside it, any remaining medicine, and any other medicines you take.