Medical Update Memo
November 9, 1999

Summary
Draxis Health Inc. announced today the availability of tizanidine hydrochloride (Zanaflex®), a new oral treatment for muscle spasticity. This is the first new oral therapy to be introduced in Canada in more than 20 years to treat this frequent symptom of multiple sclerosis. Its availability will provide people with MS and their physicians another treatment choice.

Background
Tizanidine hydrochloride (Zanaflex®) was launched today as a prescription medication to treat muscle spasticity, a frequent symptom of multiple sclerosis. It is the first new oral treatment for spasticity to be available in Canada in more than 20 years. The drug was approved by Health Canada earlier this year. It was approved in the United States in 1996 and has been available as a prescription medication for spasticity for a number of years in Europe.

Spasticity is one of the most frequently reported symptoms of MS. It is caused by an increase in voluntary muscle tone, often stimulated by movement, and can result in muscle stiffness, difficulties with movement and pain. Traditionally, treatments for spasticity have included physiotherapy, stretching exercises and medications such as balofen (Lioresal®), diazepam (Valium®) and clonazepam (Rivotril®).

Double-blind, placebo-controlled clinical trials involving people with MS in the United States and Britain and involving people with spinal cord injury in Canada and the United States found that Zanaflex reduced muscle tone (spasticity) without a decrease in muscle strength. Comparative analysis of Zanaflex with other antispasticity medications indicate equivalent efficacy in controlling spasticity, with less weakness.

The most common side effects of using Zanaflex were drowsiness, dizziness and dry mouth, which can also be found with other antispasticity medications.

Zanaflex is available in a scored oral tablet of 4mg formulation. Its peak effect occurs one to two hours after it is taken. The average dosing range is between 18mg and 24mg at a cost of $3 to $4 per day, not including pharmacy dispensing fees or other markups.

The Multiple Sclerosis Society of Canada welcomes another treatment choice for people with MS who experience spasticity as one of their MS symptoms. People with MS concerned about spasticity in MS and the potential of this new medication should consult their personal physicians.

Disclaimer
The Multiple Sclerosis Society of Canada is an independent, voluntary health agency and does not approve, endorse or recommend any specific product or therapy but provides information to assist individuals in making their own decisions.