Wex’s opiate treatment doesn’t prevent withdrawal symptoms

The phase IIa placebo-controlled study evaluated the efficacy and safety of Tetrodin (tetrodotoxin) in reducing withdrawal symptoms in 14 methadone-maintained participants. Researchers used the opioid antagonist naloxone to induce opioid withdrawal symptoms in methadone-maintained subjects to evaluate the effects of tetrodotoxin on opioid withdrawal and to serve as a model of spontaneous withdrawal which occurs when heroin or methadone use is discontinued.

The data suggest that the use of a four-day pre-treatment regimen of 30 micrograms of subcutaneous tetrodotoxin prior to the introduction of naloxone does not alleviate withdrawal symptoms. However, the results are not fully conclusive as the study group was relatively small and large variations in response were observed.

Wex say’s the experiment has helped the company to better understand tetrodotoxin’s mechanism of action, such that tetrodotoxin treatment may only be effective when administered during the withdrawal period. Hence, it is possible that in a larger study with a different treatment regimen, tetrodotoxin may prove to have clinical efficacy in this indication.

The company said it will continue to focus its efforts on the commercialization of Tectin for pain management and therefore, will not pursue the development of Tetrodin in Canada until further resources are available or a partnership/collaboration is entered into.