Vacuum Distilled Medicine
In general the answer would be no. 

While there are many distillable compounds you could extract this way (not sure how many medicinal ones, though) there are many more that would decompose or simply not be easily extracted.

This is why there are many other ways chemists commonly extract things from mixture or from plants. For example, if you wanted to extract caffeine from coffee or from coffee beans, you could use solvent-based extraction (methylene chloride works well, for example, and has been used in industrial processes to create decaffeinated coffee). There is no single easy solution, though, and often much trial and error will be required to find the right solvent to differentially extract what you want.