Contrary to initial reports, the drug tested on paid volunteers in a French study, which resulted in one death and five hospitalizations, did not contain cannabis or cannabinoids. The drug, an FAAH inhibitor manufactured by the Portuguese company Bial, was instead designed to act upon the human endocannabinoid system as a potential painkiller and treatment for anxiety. Beyond that, very little information is publicly known and as such, no conclusions can be drawn about the safety or efficacy related to future cannabis and cannabinoid research.
“Without adequate information it is impossible to advance any realistic theory about causes of toxicity,” says Daniele Piomelli, PhD, Louise Turner Arnold Chair in Neurosciences and Professor, Anatomy & Neurobiology University of California-Irvine, School of Medicine, and Editor-in-Chief of Cannabis and Cannabinoid Research. “Several structurally different FAAH inhibitors have been previously tested for human safety in rigorous Phase 1 clinical trials. These include compounds from Sanofi, Pfizer, Merck, Johnson and Johnson, and others. All these FAAH inhibitors were shown to be safe in humans.”
The human safety of multiple FAAH inhibitors suggests that toxicity of the Bial compound is unlikely to be a ‘class effect’-in other words, it is unlikely to be due to the interaction of the Bial compound with FAAH.
“It is more probable that the Bial compound interacts with another, as yet unknown protein that is responsible for the observed toxicity, or that a toxic impurity was present in the test drug,” continues Dr. Piomelli. “Of course, while we can tentatively exclude a class effect at this point, we cannot pin-point which other target might be responsible for the toxicity of the Bial compound.”