To take this baby totally off roads and since it's a research topic now
http://www.international.uni-hannover.de/krankenversicherung.html?&L=1 As far as pre-existing conditions are concerned, you should obtain all necessary medicines in your home country, since pre-existing conditions are generally not covered by German health insurance and patients have to carry their own costs.
I just googled around a bit since I never had to think about it and that's what I found at the top of the search results. I don't know if there's more to this, but there seems to be at least a precedence. It it didn't look like it's just private insurance but rather the regular public health care as far as non-citizens are concerned
![wave wave](/ubb/images/graemlins/default/wave.gif)
Michael