If such a reaction is remote, yet foreseeable to the manufacturer, the severity of the reaction (death) dictates a warning. It is a known, material risk, and the burden of warning is outweighedby the severity of the harm.
There’s no warning on the package that it could result in death. The maker could be sued in products liability for negligent failure to warn.
There was a good case in Mass. against Tylenol. One possible reaction of Tylenol is that your skin could melt and fall off (not even really exaggerating). Very remote possibility, but so, so severe. Manufacture knew it was possible, didn’t warn because it was so remote. But such a serious injury makes the risk material to a consumer, and so there’s a duty to warn.