You have to be careful with the legal status of this issue
But if you narrow it down to people who are denying the free speech rights of individuals who are publicising the existence of medical studies, or of anecdotal reports by physicians, then Section 242 of Title 18 seems to apply.
Of course, nobody will be sentenced to capital punishment for this in most cases. But I expect that a good lawyer can get a conviction with damages against the perpetrators, especially when the perp is a large powerful corporation with a monopoly, and the victim is an individual.
However if you outright tell people that HCQ cures COVID-19 and you get banned or fired, or thrown in prison, I strongly doubt that you can make a case under this law. The civil rights laws do not protect quacks and others practicing medicine without a licence.
You already know that your free speech rights do not allow you to shout ==FIRE! in a theater. There are limits. So you should think carefully about what you say, to make sure your speech is actually protected. Also, you should think about your political goals. If you want to encourage more science knowledge then focus on publicizing existing medical papers that are already in Pubmed–. There are thousands that are related to respiratory viruses and various anti-malaria treatments.