(My doctor has told me that, if I start requesting refills too frequently, then he'll start doing blood tests on me.)
That just sounds... punishing to me. Is it just me and my issues that hears it that way?
Did he finish the sentence? That he'll start doing blood tests on you...to make sure you have that amount of drug in your bloodstream, because if you don't, then you're selling it instead of taking it.
Except not, because I recently proofread an article about screens for opiates, and -- control your shock -- they're not always accurate.