Legal aspect: malpractice potential or (probably?) not?

I can’t be the only one who had this as a last minute add on in the middle of procedure & wasn’t given any kind of heads up, informed consent or even naming of the drug? I look everything up & am so careful given my known sensitivities but just didn’t have a chance while lying in a giant magnet without my phone to do my usual research to where I would have 100% declined this injection… Has anyone pursued legal for a similar issue? I’m guessing it’s not a very good chance of getting any kind of compensation but curious if anyone has tried.