Botulinum Toxin

Botulinum toxin commonly known as botox, is a powerful neurotoxin made by a bacterium Clostridium botulinum. It works by blocking the transmission of the electrical impulse from a nerve which makes a muscle contract. Thus injecting Botulinum toxin into a muscle causes muscle paralysis. The blockade is permanent and recovery is dependent on the cells making new receptors, a process that takes around 12 weeks. This is why, when used cosmetically, the effects of botulinum toxin wear off at around 3 months.

Botox® is licensed for the management of overactive bladder in adult patients with symptoms of urinary incontinence, urgency and frequency (licensed by the MHRA September 2013).

It is also licensed for the management of urinary incontinence in adult patients with neurogenic detrusor overactivity due to subcervical spinal cord injury or multiple sclerosis. It is not yet licensed to treat stress incontinence.

Suitability

You need to have had detrusor overactivity diagnosed on urodynamic testing and should have tried conventional treatments such as bladder retraining and anticholinergic medication.

It is not safe to have Botulinum toxin therapy if you are pregnant, if you are allergic to egg albumin or if you suffer from any of the following conditions: Myasthenia gravis, Eaton-Lambert Syndrome or amyotrophic lateral sclerosis.

The Procedure

Your general practitioner will need to refer you to an urologist or urogynaecologist for consideration of the treatment. If the procedure is offered to you your local urology or urogynaecology clinic can give you more information about the procedure.

The Botulinum toxin injection is given directly into the bladder muscle (detrusor). A telescope is passed through the urethra into the bladder and a fine needle is used to inject the muscle under direct vision. Usually 20 small injections are given scattered over the bladder wall. This procedure can be done under either general or local anaesthetic in a day case setting or in a clinic under local anaesthetic. It does not require overnight admission to hospital as a rule. When the effects of the Botulinum toxin wear off, the injection can be repeated. This may be after 9-12 months.

When the procedure is performed under a local anaesthetic recovery is immediate. After a general anaesthetic, you should be fit to go home after 2-3 hours. The effect of the drug should be noticeable within 3-4 days.

Success can be measured in different ways and to some extent depends on the expectations of the patient and clinician. 70-80% of patients will find the injection beneficial

Side Effects

The side effects of the procedure include passing blood in the urine and urinary tract infection. The side effects of the Botulinum toxin include voiding difficulty in 10-20% and more rarely a reaction to Botulinum toxin (flu like symptoms, generalised muscle weakness).

If you develop voiding difficulty you will need to learn intermittent self-catheterisation and may need to perform this several times a day for the first few weeks until the detrusor muscle starts to work more effectively again.

There are a few medications that interact with Botulinum toxin – including nifedipine, diltiazem, verapamil and amlodipine.

This information has been provided by:
Philip Toozs-Hobson, Clinical Director, Gynaecology Consultant, Urogynaecologist
Birmingham Women’s Hospital

Claire Burton, Subspeciality Trainee Urogynaecology, Department of Pelvic Floor Medicine, Birmingham Women’s Hospital