Good luck!
My advice is don't let them know you have bipolar if you can avoid it. Heart condition is good enough.
Make sure the testing place for the drug tests knows you are prescription medications. I don't really know the rules about how they report, but make sure they know.
I had to take a drug test to get my job, too. I wasn't on anything at the time, but I have a friend here at work that doesn't want to do narcotics for her fibromyalgia, she want's to try the medical marajuana lotion, but is afraid to because of our HR person....

It's not right.
You're going to do fine.