That's all I wanted to know. Here's the suggested solution.
These are not the standard print abbreviations that we are accustomed to in braille, like oz, ft, in, and so on. These are also not the standard print symbols that we also are accustomed to in braille like $ and %. The braille symbol for print sign is dot 4. So for Rx you will identificy that as
Even a familiar one like 1/2 gets a dot 4 because it is shown by the technical medical symbol.
Write a TN that explains that these technical medical symbols are used in print. Use the same term that the book uses for medical symbols. Maybe it's just medical symbols. Then list each one with its braille followed by the same identification that is given in the book.
I know that's a lot of dots for some of these, but that is the way the reader will know that a technical symbol is used there. It accurately conveys the print.
We are not concerned with what that print symbol actually looks like. We don't describe symbols (except in certain rare cases for a specific reason). We don't describe what the percent sign looks like in print, for instance. We just list it with its braille equivalent. I'm suggesting that you do the same here. And since there is no braille eqivalent, use the dot 4 with identification and that tells the reader that the medical symbol that means that is what it in the print. Use the identifications as given in the print. In that way, we faithfully follow the print. Don't forget the TN first that explains all this.