Evidence of a muscle relaxant used to treat people with multiple sclerosis and spinal cord injuries has been found in samples taken from professional cyclists, according to a French study.
Hair samples were taken from seven runners during a “three-week cycle race” in France, according to the report.
The name of the team and cyclists involved are not named in the report – published in the « Wiley Analytical Science Journal » which has been reviewed by VeloNews in full – but that would indicate that the samples were collected during the Tour de France in July.
A pathologist collected the hair samples in the presence of the police and the drug tizanidine was identified in three of the seven samples collected. According to the report, tests for other substances have been ordered, but have not been detailed.
Marketed under names such as Sirdalud or Zanaflex, tizanidine is not prohibited by the rules of the World Anti-Doping Agency (WADA).
“Tizanidine is not a drug banned by WADA but appears to have properties of interest to athletes because it is a short-acting muscle relaxant,” the report states. “However, as it can cause drowsiness, it should not be used while running but at night or at bedtime to help recovery. Perhaps the drug can be used to prevent cramps as it has a relaxing effect on the muscles. There is nothing published in the scientific literature on this specific topic.
“It is difficult to know precisely the purpose of its use because tizanidine can be used in combination with other drugs. Athletes can experience a combination [sic] that they perceive as useful. Nonetheless, they sometimes have weird consumptions that look like looking for a placebo effect rather than real evidence of improved performance, especially when a drug isn’t banned.
The study gives a behind-the-scenes look at products some top professional runners could use without breaking strict anti-doping rules.
Although not banned by the AMA, tizanidine can only be obtained in France through what is called a “temporary nominative authorization for use”, a system designed to give people with serious illnesses or rare early access to certain drugs.
The drug must be ordered from hospital services and cannot be purchased at a pharmacy.
Tizanidine works by blocking nerve impulses – a feeling of pain – sent to your brain. In addition to injuries, it is also sometimes used to treat opioid and alcohol withdrawal.
According to the published report – written by scientists Pascal Kintz, Laurie Gheddar and Jean-Sébastien Raul – the French public health division within the national police commissioned the study. The aim was to “test tizanidine in hair samples collected from international athletes”.
The level of the drug found in the three positive hair samples was 1.1, 3.7 and 11.1 pg / mg.
As previous studies were not conducted, the study indicated that it was not yet possible to determine the amount of tizanidine expected in hair samples compared to the initial dose. However, he called the amounts found “excessively small”.
The report concluded that it was “still not clear” whether tizanidine could be used to improve performance.