Doctors, in the US at least, are a bit less than helpful when you ask about this kind of stuff, and I've had more than one actually act offended when asked about how/why what they're prescribing works. I know that in IT, if a client asks us how something works, I'm more than happy to explain, or at least point them in the right direction and link them to some documentation and/or how-to articles. With doctors, I typically get more of a "it just does" / "it's complicated and you wouldn't understand" / [very technical explanation, not even trying to make it make sense to laypersons].