Primary care offices sometimes take on PA's and NP's who are on rotation. Presumably, these PA's or NP's could be supporting cardiologists in specialty practices. Thus, detailing the PC office that they work in is progressive to them understanding the therapy. Thats justification #1.
Primary care is just that -- your primary care. Thus, if you are preparing for surgery, preparing for vacation, preparing for anything, you will likely consult your primary care doctor if you feel it is vigilant to do so. If you have ACS, you probably think it is vigilant (or should). Thus, the primary care physician should understand what Brilinta is and what the pharmacological implications are. Also should be comfortable refilling for you if, for some strange reason, your specialist is unavailable. That justification #2
When I worked in primary care selling Crestor, some of our biggest writers were primary care/GASTROENTEROLOGISTS! The gastros were poaching patients from the primary care physicians that were sending them there, and taking them on in the primary care setting. This is becoming increasingly prevalent, as ACO's and PCMH's create a multi-specialty setting. THUS, it was important for to detail Gastros on Crestor b/c they were treating in PC too (or referring to PC counterparts in the same building, and discussing Crestor!) Knowledge is good for everyone! Thats justification #3
I think, as long as you're not incentivized on the scripts that a PC is doling out, then you are free and clear completely. I still think you could even make a case for incentivizing in PC setting though, given the PC physician does the things mentioned above.