Lemme take a crack at it:
"I do not know where family doctors have such unreadable and confusing handwriting; even so, extraordinary pharmaceutical knowledge making up for the impossibility of reading makes unusual the words' status of difficult understanding."
So basically the author doesn't understand why doctors have such messy handwriting. He assumes that their superior knowledge of medicine is what affects their handwriting.
"I do not know where family doctors have such unreadable and confusing handwriting; even so, extraordinary pharmaceutical knowledge making up for the impossibility of reading makes unusual the words' status of difficult understanding."
So basically the author doesn't understand why doctors have such messy handwriting. He assumes that their superior knowledge of medicine is what affects their handwriting.