Bladder Botox After Spinal Cord Injury: Benefits, Risks and What to Expect
A spinal cord injury can change the way your bladder stores and releases urine. You may experience bladder spasms, urine leakage, frequent catheterisation or high pressure inside the bladder.
Bladder Botox is a minimally invasive treatment that relaxes the bladder muscle. It can reduce leakage, improve bladder capacity and help the bladder store urine at a safer pressure.
International guidelines recommend bladder Botox for some people with spinal cord injury when tablets do not work well enough or cause troublesome side effects.[1,2]
How can a spinal cord injury affect the bladder?
The bladder is controlled by nerves that carry messages between the brain, spinal cord and urinary system.
After a spinal cord injury, these messages may be interrupted. The bladder muscle and the muscle that controls urine flow may no longer work together properly.
One common problem is called neurogenic detrusor overactivity. This simply means that the bladder muscle squeezes or contracts when it should be relaxed and filling with urine.
This can cause:
urine leakage between catheterisations
sudden bladder spasms
urine leaking around a catheter
the need to catheterise more often
a bladder that holds less urine
high pressure inside the bladder
episodes of autonomic dysreflexia in people at risk
Some people do not feel pain or discomfort even when their bladder pressure is dangerously high.
Over time, high bladder pressure can push urine back towards the kidneys. This may increase the risk of kidney swelling, infection or kidney damage.
For this reason, bladder treatment after spinal cord injury is not only about preventing leakage. The main goals are to protect the kidneys, keep bladder pressure low and make bladder care manageable.[1,2]
What is bladder Botox?
Botox is a brand name for onabotulinumtoxinA, a purified form of botulinum toxin type A.
When Botox is injected into the bladder wall, it blocks some of the nerve signals that make the bladder muscle squeeze.
This helps the bladder relax so that it can:
hold more urine
store urine at a lower pressure
contract less often
cause fewer leaks and spasms
The effect is temporary. It usually wears off over time, so treatment may need to be repeated.
Who may benefit from bladder Botox?
Bladder Botox may be considered when bladder spasms, leakage or high bladder pressure continue despite medication and appropriate catheter care.
It may be helpful if you have:
leakage between intermittent catheterisations
high bladder pressure on bladder testing
a bladder that holds only a small amount of urine
frequent or painful bladder spasms
urine leaking around a urethral or suprapubic catheter
side effects from bladder-relaxing tablets
poor bladder control despite medication
bladder problems that trigger autonomic dysreflexia
International guidelines recommend bladder Botox for suitable people with spinal cord injury when bladder-relaxing medication does not provide enough benefit.[1,2]
However, Botox is not the right treatment for every type of leakage.
Urine leakage can also be caused by:
a blocked catheter
a urinary infection
constipation
bladder stones
not catheterising often enough
weakness in the muscle that holds urine in
These possible causes should be checked before Botox treatment is recommended.
How well does bladder Botox work?
Research shows that bladder Botox can:
reduce urine leakage
reduce bladder spasms
increase how much urine the bladder can hold
lower pressure inside the bladder
improve quality of life
A 2024 review of studies involving people with spinal cord injury found that Botox increased bladder capacity by an average of about 145 millilitres. It also lowered maximum bladder pressure by about 30 cmH₂O.[3]
These figures are averages. Some people experience a larger improvement, while others have a smaller response.
Long-term studies suggest that Botox can continue to work with repeated treatments. One study found that the benefits continued over four years without new safety concerns.[5]
Another study found that about half of the people who started treatment were still receiving Botox injections 10 years later.[6]
Not everyone becomes completely dry. A successful result may mean:
fewer leaks
fewer spasms
larger amounts of urine drained with each catheterisation
longer gaps between catheterisations
safer bladder pressure
Can bladder Botox help autonomic dysreflexia?
Autonomic dysreflexia is a sudden and potentially dangerous rise in blood pressure. It most commonly affects people with spinal cord injuries at or above the T6 level.
Common bladder-related triggers include:
an overfull bladder
a blocked catheter
a urinary infection
bladder spasms
bladder procedures
A small study involving 25 people with spinal cord injuries at or above T6 found that bladder Botox reduced the frequency and severity of bladder-related autonomic dysreflexia.[8]
However, more research is needed. Botox does not replace your usual autonomic dysreflexia prevention and emergency plan.
People at risk may need blood-pressure monitoring and special precautions during the Botox procedure.
What tests may be needed before treatment?
Your urologist will review your bladder symptoms, general health and current bladder-care routine.
The assessment may include:
the level and severity of your spinal cord injury
how you currently empty your bladder
how often you catheterise
the amount of urine drained each time
urine leakage and bladder spasms
urinary infections
bowel problems and constipation
your current medications
your hand function or access to caregiver support
previous episodes of autonomic dysreflexia
kidney function tests
kidney and bladder imaging
previous bladder-pressure testing
Urodynamic testing
Urodynamic testing measures how the bladder fills, stores urine and empties.
It can show:
how much urine the bladder holds
whether the bladder squeezes unexpectedly
whether pressure becomes too high
whether the bladder and urinary sphincter work together
whether urine is being stored safely
This test is particularly important when there is concern about high bladder pressure, kidney damage, worsening leakage, recurrent infections or poor bladder stretching.
Your urologist may also recommend repeat testing after treatment to check that bladder pressure has improved.[1,2]
What happens during the procedure?
Bladder Botox is usually given through a cystoscope. A cystoscope is a thin camera that is gently passed through the urethra and into the bladder.
During the procedure:
The urologist examines the inside of the bladder.
A fine needle is passed through the cystoscope.
Small amounts of Botox are injected into several areas of the bladder wall.
The bladder is emptied.
You are monitored during recovery.
A commonly used dose for bladder problems caused by spinal cord injury is 200 units of onabotulinumtoxinA. The dose and injection pattern may vary depending on your condition and the product being used.
The procedure may be performed using:
local anaesthetic
sedation
spinal anaesthetic
general anaesthetic
The best option will depend on your bladder sensation, level of injury, bladder spasms, previous procedures and risk of autonomic dysreflexia.
Many people can return home on the same day.
How should I prepare?
Before the procedure, your treating team may:
test your urine if infection is suspected
treat a symptomatic urinary infection
review blood-thinning medications
discuss your catheter plan after the procedure
arrange an anaesthetic review
prepare a plan for autonomic dysreflexia
Do not stop blood-thinning medication unless the doctor who manages it tells you to do so.
When does Botox start working?
Some people notice an improvement within several days. For others, it may take one to two weeks or longer to feel the full benefit.
Possible improvements include:
fewer urine leaks
fewer bladder spasms
less urine leaking around a catheter
larger catheterised urine volumes
longer gaps between catheterisations
fewer bladder-related episodes of autonomic dysreflexia
The effect often lasts around six to nine months, although this varies between patients.
Some people need treatment sooner, while others continue to benefit for a year or longer. In one long-term study, the average duration of benefit was about nine months.[5]
Treatment is usually repeated when the benefit begins to wear off rather than automatically being performed on a fixed date.
Will I still need to catheterise?
In most cases, yes.
Bladder Botox helps the bladder store urine. It does not usually restore normal nerve control or allow the bladder to empty normally.
If you already perform clean intermittent catheterisation, you will usually continue doing so after treatment.
Your catheterisation times may need to be adjusted depending on:
how much you drink
how much urine is drained
how well the Botox works
your bladder-pressure results
If you currently pass urine without a catheter, Botox may make it harder to empty your bladder.
You may need to begin intermittent catheterisation after the procedure. Your urologist should discuss this risk with you before treatment.[1,2]
What are the possible risks?
Bladder Botox is generally safe, but all medical procedures carry some risk.
Urinary infection
A urinary tract infection is one of the most common problems after bladder Botox.
Symptoms after spinal cord injury may include:
fever or chills
feeling generally unwell
increased muscle spasms
new or worsening leakage
cloudy or strongly smelling urine
increased episodes of autonomic dysreflexia
Many people who use catheters have bacteria in their urine without having an infection. Antibiotics are not always needed unless symptoms are present.
Blood in the urine
A small amount of blood or pink-coloured urine can occur after the procedure.
This is usually mild and settles quickly. Heavy bleeding or bleeding that does not improve should be assessed.
Difficulty emptying the bladder
Botox can weaken the bladder’s ability to squeeze urine out.
For someone already using intermittent catheterisation, this may make little practical difference.
Someone who normally urinates without a catheter may need to begin intermittent catheterisation temporarily or permanently.
Autonomic dysreflexia
The bladder procedure itself may trigger autonomic dysreflexia in people with higher spinal cord injuries.
Appropriate anaesthesia, blood-pressure monitoring and access to emergency treatment can reduce this risk.
Botox may not work well enough
Some people have only a partial improvement or no meaningful benefit.
This may happen because of:
very poor bladder elasticity
severe scarring of the bladder
an untreated blockage
catheter problems
leakage caused by a weak urinary sphincter rather than bladder spasms
Rare effects outside the bladder
Very rarely, Botox can affect muscles in other parts of the body.
Seek urgent medical attention if you develop:
unusual widespread muscle weakness
difficulty swallowing
difficulty speaking
breathing problems
Reviews of the available research suggest that urinary infection, difficulty emptying the bladder and temporary blood in the urine are the most commonly reported side effects.[3,4]
Does Botox replace regular kidney and bladder checks?
No.
Having fewer leaks does not always mean that your bladder pressure is safe.
People with spinal cord injury may still need regular:
kidney function blood tests
kidney and bladder ultrasounds
reviews of their catheter routine
checks for bladder or kidney stones
assessment of urinary infections
urodynamic testing when needed
International guidelines recommend lifelong bladder and kidney follow-up based on each person’s level of risk.[1,2]
What happens if Botox does not work?
Further treatment will depend on the cause of the bladder problem.
Options may include:
changing how often you catheterise
adjusting bladder medication
using medication together with Botox
changing the type of catheter
treating constipation
removing bladder stones
treating a blockage in the urinary tract
procedures to improve urinary control
bladder enlargement surgery
urinary diversion surgery in selected cases
Larger operations are usually considered only when less invasive treatments cannot keep the bladder safe or provide manageable bladder control.
Take home message
Bladder Botox is a well-established treatment for bladder overactivity after spinal cord injury.
It may help:
reduce urine leakage
reduce bladder spasms
increase bladder capacity
lower bladder pressure
protect the kidneys
improve day-to-day bladder management
The decision to have Botox should not be based on leakage alone. Your urologist will also consider your bladder pressure, kidney health, catheter routine, risk of autonomic dysreflexia and long-term goals.
Bladder assessment after spinal cord injury in Brisbane
Dr Jack Crozier is a Brisbane urologist with an interest in spinal cord injury bladder management and complex neuro-urological conditions.
A confidential consultation provides an opportunity to review bladder spasms, catheter leakage, urinary infections, bladder pressure, kidney monitoring and whether bladder Botox may be suitable.
This article provides general information and does not replace individual medical advice. Seek urgent medical care if you develop severe symptoms of autonomic dysreflexia, a blocked catheter that cannot be relieved, fever with significant illness, heavy urinary bleeding, severe muscle weakness, difficulty swallowing or difficulty breathing.
References
Sartori AM, Kessler TM, Castro-Díaz DM, et al. Summary of the 2024 update of the European Association of Urology guidelines on neurourology. Eur Urol. 2024;85(6):543-555. doi:10.1016/j.eururo.2024.03.026.
Ginsberg DA, Boone TB, Cameron AP, et al. The AUA/SUFU guideline on adult neurogenic lower urinary tract dysfunction: treatment and follow-up. J Urol. 2021;206(5):1106-1113. doi:10.1097/JU.0000000000002239.
Vaheb S, Mokary Y, Ghoshouni H, Mirmosayyeb O, Ghaffary EM, Shaygannejad V, et al. Onabotulinum toxin A improves neurogenic detrusor overactivity following spinal cord injury: a systematic review and meta-analysis. Spinal Cord. 2024;62(6):285-294. doi:10.1038/s41393-024-00992-9.
Yu PH, Wang CC. Adverse effects of intravesical onabotulinumtoxinA injection in patients with idiopathic overactive bladder or neurogenic detrusor overactivity: a systematic review and meta-analysis of randomized controlled studies. Toxins. 2024;16(8):343. doi:10.3390/toxins16080343.
Kennelly M, Dmochowski R, Schulte-Baukloh H, et al. Efficacy and safety of onabotulinumtoxinA therapy are sustained over 4 years of treatment in patients with neurogenic detrusor overactivity: final results of a long-term extension study. Neurourol Urodyn. 2017;36(2):368-375. doi:10.1002/nau.22934.
Hebert KP, Klarskov N, Bagi P, Biering-Sørensen F, Elmelund M. Long term continuation with repeated botulinum toxin A injections in people with neurogenic detrusor overactivity after spinal cord injury. Spinal Cord. 2020;58(6):675-681. doi:10.1038/s41393-019-0411-0.
Chen SF, Jiang YH, Jhang JF, Kuo HC. Satisfaction with detrusor onabotulinumtoxinA injections and conversion to other bladder management in patients with chronic spinal cord injury. Toxins. 2022;14(1):35. doi:10.3390/toxins14010035.
Huang M, Zheng H, Huang T, Yang X, Liu Q, Li Q, et al. Intravesical injection of botulinum toxin type A may be an effective treatment option for autonomic dysreflexia in patients with high-level spinal cord injury. J Spinal Cord Med. 2024;47(1):74-78. doi:10.1080/10790268.2022.2135230.
Chen SF, Kuo HC. Will repeated botulinum toxin A improve detrusor overactivity and bladder compliance in patients with chronic spinal cord injury? Tzu Chi Med J. 2021;33(2):101-107. doi:10.4103/tcmj.tcmj_77_20.
Denys P, Dmochowski R, Aliotta P, et al. Positive outcomes with first onabotulinumtoxinA treatment persist in the long term with repeat treatments in patients with neurogenic detrusor overactivity. BJU Int. 2017;119(6):926-932. doi:10.1111/bju.13795.
