Overactive bladder can have a significant impact on everyday life. The sudden need to find a toilet, frequent trips to the bathroom, waking repeatedly at night and episodes of urinary leakage can interfere with work, travel, exercise, sleep and social activities.

When bladder training, pelvic floor therapy and medications have not provided adequate relief, Botox injections into the bladder can be an effective treatment option.

What is overactive bladder?

Overactive bladder (OAB) is a condition characterised by urinary urgency, usually accompanied by increased urinary frequency and waking at night to pass urine (nocturia), with or without urgency urinary incontinence.

Typical symptoms include:

• A sudden, difficult-to-defer urge to urinate
• Passing urine more frequently than expected
• Waking several times during the night to urinate
• Leakage of urine before reaching the toilet
• Planning activities around access to toilets

Importantly, similar symptoms can sometimes be caused by urinary infection, bladder stones, bladder obstruction or other urinary tract conditions. Appropriate assessment is therefore important before treatment.

What is bladder Botox?

Botox® is the trade name for onabotulinumtoxinA, a purified form of botulinum toxin type A.

Although Botox is widely known for cosmetic treatments, it has several established medical applications, including treatment of bladder dysfunction.

When injected into the bladder muscle, Botox reduces excessive nerve signalling to the bladder and decreases involuntary bladder contractions. The bladder becomes less “trigger-happy”, allowing it to store urine for longer before producing an urgent need to empty.

Clinical studies demonstrate that intradetrusor onabotulinumtoxinA improves urgency urinary incontinence, urinary frequency, urgency and nocturia compared with placebo.

Who may benefit from bladder Botox?

Botox may be considered for patients with troublesome overactive bladder symptoms, particularly when conservative or medication-based treatments have been unsuccessful, poorly tolerated or are not desired.

Current guidelines recommend intradetrusor botulinum toxin as an established minimally invasive treatment for appropriately selected patients with OAB.

It may be particularly useful for patients experiencing:

• Severe urinary urgency
• Urgency urinary incontinence
• Frequent urination
• Significant nocturia
• Persistent symptoms despite bladder training
• Persistent symptoms despite pelvic floor rehabilitation
• An inadequate response to medications
• Unacceptable medication side effects

Some patients choose procedural treatment because they would prefer not to take long-term medication.

Other minimally invasive options for refractory OAB include sacral neuromodulation and tibial nerve stimulation.

Assessment before Botox treatment

Before proceeding, your urologist will usually assess the nature and severity of your bladder symptoms.

Depending upon the circumstances, this may include:

• Medical and urinary history
• Urinalysis and/or urine culture
• Bladder or voiding diary
• Measurement of urinary flow
• Ultrasound assessment of the bladder
• Measurement of the post-void residual (PVR) to determine how well the bladder empties
• Urodynamic testing in selected patients

AUA/SUFU guidelines specifically recommend measuring the post-void residual before intradetrusor Botox treatment. Particular caution may be appropriate when the residual urine is already significantly elevated because Botox can temporarily reduce the strength of bladder emptying.

How is Botox injected into the bladder?

Bladder Botox is administered using a procedure called cystoscopy.

A fine telescope is passed through the urethra into the bladder. A specialised injection needle is then passed through the cystoscope.

Small quantities of Botox are injected at multiple sites across the bladder wall.

For idiopathic overactive bladder, onabotulinumtoxinA 100 units is a commonly used treatment regimen and is the dose recommended in European guidelines for refractory OAB/urgency urinary incontinence.

The procedure may be performed using:

• Local anaesthetic placed into the bladder
• Sedation, or
• General anaesthesia

The most appropriate option depends on the patient, the clinical setting and individual preference.

The procedure itself is generally relatively short, and most patients can go home on the same day.

What happens after the procedure?

Some patients notice an improvement within several days, although the full effect may take a little longer to become apparent.

As Botox begins to work, patients may experience:

• Less urgency
• Fewer visits to the toilet
• Fewer episodes of urgency incontinence
• Less nocturia
• Improved bladder capacity
• Improved confidence when away from a toilet

Quality-of-life improvement following treatment can be substantial in appropriately selected patients.

How long does bladder Botox last?

Botox is not permanent.

The nerve endings gradually recover and bladder symptoms may eventually return. The duration of benefit varies considerably between individuals, but treatment commonly provides symptom control for a number of months.

When symptoms return, the injections can usually be repeated.

Evidence suggests that repeat treatment generally remains effective, although some patients eventually choose an alternative treatment.

What are the side effects of bladder Botox?

Most patients tolerate the procedure well, but Botox treatment is not without risk.

Urinary tract infection

Urinary tract infection (UTI) is one of the most important and common complications following bladder Botox.

Symptoms can include:

• Burning when passing urine
• Increased frequency
• Cloudy or offensive-smelling urine
• Lower abdominal discomfort
• Fever or feeling unwell

Botox treatment is associated with an increased incidence of UTI.

Difficulty emptying the bladder

Botox deliberately reduces bladder muscle activity. Occasionally it works a little too effectively.

Some patients consequently develop an increased amount of urine remaining in the bladder after urination, known as an increased post-void residual.

This may cause:

• Difficulty starting urination
• A weak urinary stream
• A feeling of incomplete emptying
• Abdominal discomfort
• Recurrent urinary infection

For this reason, bladder emptying may be reassessed following treatment, particularly if symptoms suggest incomplete emptying.

Temporary need for self-catheterisation

A small proportion of patients may be unable to empty their bladder adequately after Botox treatment.

If this occurs, clean intermittent self-catheterisation (CISC) may temporarily be required until the effect decreases and normal bladder emptying returns.

Patients should therefore understand this possibility and be willing and physically able to perform catheterisation if necessary before proceeding with treatment. Both EAU and AUA/SUFU guidance emphasise counselling patients about this risk.

Blood in the urine

A small amount of blood in the urine can occur following cystoscopy and the injections themselves. This is usually temporary.

Discomfort passing urine

Mild burning, urgency or bladder discomfort can occur for a short period following the procedure.

Rare systemic effects

Botulinum toxin can very rarely produce effects away from the injection site, potentially causing muscle weakness or other neurological symptoms.

Patients should seek medical attention if they develop significant weakness, difficulty swallowing or breathing difficulties following treatment.

Who should not have bladder Botox?

Intravesical Botox is not suitable for everybody.

Important contraindications include:

• An active urinary tract infection
• Acute urinary retention in a patient who is not routinely catheterising
• Inability or unwillingness to perform intermittent catheterisation if it becomes necessary
• Known hypersensitivity to Botox or its components
• Certain neuromuscular disorders, including myasthenia gravis and Eaton-Lambert syndrome

These contraindications are reflected in Australian Botox product information.

Additional caution may be required in patients with:

• Significant pre-existing incomplete bladder emptying
• Recurrent urinary tract infections
• Bladder outlet obstruction
• Previous urinary retention
• Certain neurological conditions
• Frailty or significant medical comorbidity

Patients with recurrent UTIs require particularly careful consideration because Botox may further increase the risk of urinary infection.

Botox in men with overactive bladder

Men can also experience overactive bladder, but it is important to establish whether urinary symptoms are being caused or aggravated by bladder outlet obstruction from an enlarged prostate.

A man with urgency, frequency and nocturia may therefore require assessment of his prostate, urinary flow and residual urine before bladder Botox is considered.

In some men, treatment of prostate obstruction may need to be considered before or alongside treatment directed at the bladder.

Botox versus other treatments for overactive bladder

Botox forms part of a broader range of OAB treatments rather than being the right treatment for every patient.

Management may include:

Conservative treatment

Bladder training, modification of fluid intake, reducing caffeine, weight management where appropriate and pelvic floor rehabilitation.

Medication

Antimuscarinic medications and beta-3 adrenergic agonists can reduce urgency, frequency and urgency incontinence.

Intravesical Botox

An effective minimally invasive treatment that does not require a permanent implant, but needs to be repeated when its effect wears off.

Tibial nerve stimulation

Electrical stimulation of the tibial nerve can modify the nerve pathways involved in bladder control.

Sacral neuromodulation

A small implanted device stimulates the sacral nerves controlling bladder function and can provide longer-term treatment for selected patients.

Current OAB guidelines recognise Botox, tibial nerve stimulation and sacral neuromodulation as established minimally invasive treatment options when conservative or pharmacological therapy has provided inadequate results or unacceptable side effects.

When should I consider bladder Botox?

You may wish to discuss Botox with your urologist if overactive bladder is having a significant effect on your quality of life and:

• Bladder training and conservative measures have not provided adequate control
• Medications have not worked sufficiently
• Medication side effects are unacceptable
• You do not wish to continue long-term medication
• You would like to consider a minimally invasive treatment

The decision should take into account both the potential benefits and the possibility of urinary infection, incomplete bladder emptying and temporary catheterisation.

The bottom line

Intravesical Botox is an effective and well-established treatment for overactive bladder and urgency urinary incontinence.

For appropriately selected patients, it can significantly reduce urinary urgency, frequency and leakage and improve quality of life. Its main limitations are that the effect is temporary and repeat injections are usually required.

The two most important complications to understand are urinary tract infection and incomplete bladder emptying, with a small proportion of patients requiring temporary intermittent catheterisation.

A consultation with a urologist can help determine whether Botox, medication, tibial nerve stimulation, sacral neuromodulation or another treatment is most appropriate for your individual bladder symptoms.

This information is intended for general patient education and does not replace individual medical advice. Treatment recommendations should be based on assessment by an appropriately qualified healthcare professional.

So. if this sounds like an option for your overactive bladder, come see your friendly Brisbane Urologist, Uro-Jo, in either Brisbane, Caboolture or on Bribie Island