This seems like a failure of the Canadian counterpart of the US FDA. Drug trials are generally extensive enough to surface side effects, and severe side effects lead to cancellation of trials or at least label warnings.
The FDA is the definition of regulatory capture.
A long line of examples. Their still holding to the line that Glyphosate (roundup) does't cause cancer and that Marijuana has no proven medical value.
I've a special place for the Texas Railroad Commission, for example:
https://independentleaguetx.org/legislature-fails-texas-rail...