Trivial for Apple to compile a list of all medications and fix this.
Of course, not everyone actually wants autocorrect. For me it's about 50% helpful and 50% a hindrance.
What could also work is having multiple hooks (different "niche" dictionaries) which could be enabled or disabled.
In SwiftKey you can select multiple languages (dictionaries) which should be supported (and corrected, if you opt for that option).
But what I mean is that say a user could enable a medication dictionary, or a UNIX manual dictionary, or a law dictionary, or...
https://druginfo.nlm.nih.gov/drugportal/, for example.