June 26, 2014

Health Canada approves Botox® to treat neurogenic bladder

Health Canada approved the use of Botox to treat neurogenic bladder (Neurogenic Detrusor Overactivity) associated with MS and spinal cord injury. Botox is a powerful neurotoxin that temporarily blocks connections between the nerves and muscles, resulting in short-term relaxation of the targeted muscle. Injections have been shown in clinical trials to relieve spasticity in individual muscles for three to nine months.

Update on BOTOX®
Botox was approved in June 2012 by the by the Common Drug Review (CDR) of the Canadian Agency on Drugs and Technologies in Health (CADTH). Read more

Two double-blind, placebo-controlled, randomized, multi-centre phase III clinical studies involving 691 participants with MS or spinal cord injury with urinary incontinence were randomized to receive either 200 Units of Botox ®, 300 Units of Botox®, or placebo. Significant improvements compared to placebo were observed for Botox® in both studies.

Injection of the bladder muscle with Botox is performed using cystoscopy, a procedure that allows a physician to visualize the interior of the bladder. Cystoscopy may require general anesthesia. According to the Health Canada label, Botox is approved as a 200U dose for people with urinary incontinence due to detrusor (the primary bladder muscle) overactivity associated with a neurologic condition. People are to be considered for retreatment when the clinical effect of the previous treatment wears off but no sooner than 3 months from the prior bladder injection. The safety and efficacy data beyond two treatments are limited.

The most common adverse events included urinary tract infection and urinary retention. The medication carries a boxed warning that Botox injections may cause serious side effects that can be life threatening. These include problems swallowing, speaking or breathing, and the possibility that the toxin may spread to other areas of the body away from the injection site.

The next step following Health Canada approval is for Botox to be reviewed by the Common Drug Review (CDR) of the Canadian Agency on Drugs and Technologies in Health (CADTH). The MS Society of Canada has provided input from the viewpoint of potential users to the Common Drug Review (CDR) for its review of Botox. CDR is a pan-Canadian process for reviewing clinical, cost-effectiveness and patient evidence for drugs. It also provides formulary listing recommendations to Canada’s publicly funded drug plans (except Quebec).

Botox is a registered trademark of Allergan, Inc.

With information from Health Canada and the National MS Society (USA).