What is botulinum toxin?
Botulinum toxin is the most poisonous biological substance known. It is a deadly toxin produced by the bacterium Clostridium botulinum. The toxin is a neurotoxin, as it affects neural signals in the body. The substance blocks a nerve cell from releasing its neurotransmitter, which usually transfers a signal to another nerve or muscle. This results in paralysis. Paralysis of the body’s muscles is deadly, as muscle contractions are essential, because breathing and the heart’s pumping power are dependent on them.
Over the last 50 years, botulinum toxin has gone from being known as the cause of a deadly disease to being known as an effective treatment for a range of diseases. Among others, the toxin can treat dystonia – a movement disorder, headaches, drooling, hyperhidrosis and other chronic conditions, where treatment options are limited. In addition, it is used in cosmetic treatments, where it is known as Botox®. The toxin is generally well-tolerated and has few side-effects.
Botulinum toxin against overactive bladder
Recently, the toxin has become known as an alternative treatment of overactive bladder. Overactive bladder is a condition where patients experience a frequent and sudden urge to urinate, and involuntary loss of urine, or urge incontinence. In other words, you pee your pants. The cause is an overactive detrusor muscle, causing it to contract spontaneously, uncontrollably and more frequently than usual.
One solution to the problem could be injections with botulinum toxin. This minimally invasive treatment for overactive bladder could be a solution for patients who react badly to the current overactive bladder treatments. Injecting Botox ® into the detrusor muscle so its overactivity is reduced and it relaxes has proven efficient in reducing symptoms associated with the condition.
Conventional treatment of overactive bladder today
Today, overactive bladder is often treated through lifestyle changes and medications. For instance, it is recommended that you limit your intake of beverages containing caffeine and that you do not drink anything three hours before bedtime. Medicines against overactive bladder include the so-called antimuscarinic drugs. However, there is a need for alternative treatments as some patients experience severe side-effects, do not respond well or take other drugs that contraindicate the medication. Previously, patients have been offered surgical procedures, when medication was not an effective option. The surgical procedures involve expanding the bladder or sacral neuromodulation. With more insight into the qualities of botulinum toxin, this alternative treatment has gained more attention.
What does research say about this treatment?
A literature review has collected data from 18 different studies which have examined the effect and safety of Botox ® for treating overactive bladder in patients who were resistant to antimuscarinic drugs. These patients were injected with botulinum toxin in the detrusor muscle. The percentage of patients whose symptoms disappeared completely after the treatment ranged from 42% - 87 % in the 18 different studies. Treatment with Botox® resulted in a 60-80% decrease in urinary incontinence episodes and a 40-60% decrease in urinary frequency complaints, as well as a 35-65% increase in patients’ quality of life.
Researchers also tested the bladder function. They measured the pressure inside the detrusor muscle while it was filling and how much the bladder could contain before the patient felt the urge to urinate. The detrusor pressure decreased 40-60 % and bladder capacity increased by 40-60 % as well.
Based on this, researchers were able to conclude that using Botox® to treat overactive bladder had a significantly beneficial and pronounced effect.
The effect occurs gradually
In the first couple of days after the treatment, the injection of Botox ® does not have a pronounced effect, and therefore patients often have to wait a week before experiencing symptom relief. The effect typically lasts for 6-12 months, depending on patient and dosage. The bigger the dosage, the longer the effect lasts, but at the same time there is an increased risk of urinary retention. This means that the urine is held back an accumulated in the bladder, which results in complications including kidney damage.
In the autumn of 2011, botulinum toxin was approved by the FDA as a treatment of overactive bladder caused by neurogenic disturbances. This meant that overactive bladder patients who were unsuited for medical treatment could be fortunate enough to avoid getting up to pee at night or to worry about peeing their pants. Today the treatment is offered to patients with overactive bladder in the UK as well.
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