In the public sector, I have found that the American Disabilities Act has helped provide some protection for workers with medical conditions. Whether the ADA actually covers a situation or not, just bringing up the ADA in conversation can get results.

In some cases, employers are required to accommodate one's medical condition with special equipment or making changes to the work environment. I'm sure its a more persnickty problem in private enterprise.

Your medical condition should remain as private as you wish it to be; but keep in mind that if your medication affects your job performance, the boss will only see a job performance problem. Most good bosses will accommodate medical conditions and daily meds to keep productive experienced employees.