There were many times in my career while I was working in retail pharmacy when a physician or a dentist presented me with controlled-substance prescription written for himself/herself or a family member, wanting me to fill it for them, and I refused.
In some of those cases, something bad later happened, and subsequent investigations revealed that those physicians or dentists (or their family members) had substance abuse problems and were getting their prescriptions filled at multiple pharmacies in order to hide their problem.
Of course, I learned early that if you're going to refuse to fill a self-prescribed prescription then you're going to get grief from not only the prescriber, but sometimes from your co-workers or supervisors who don't understand (or care about) the potential problems or conflict of interest.
In a couple of instances, I was even reported to the BOP for refusing to fill their prescriptions. States vary in their rules about pharmacists' rights to refuse to fill prescriptions, so I once had to endure a cross-examination to justify my refusal. It was a hassle, but the BOP sided with my actions.
In essence, I refuse to enable another healthcare provider's potential substance abuse problem, or to become indirectly responsible when something bad happens after I filled their prescription. I'm not going to be sucked into any schemes, become part of the problem, and possibly hurt someone.
And the reason that I refuse to fill controlled-substance prescriptions for providers who self-diagnose and self-treat is specifically highlighted in the following video.
Source: 'Doctor of the Year' Arrested on DUI Charges After Crash
What would you do? Would you want to be the pharmacist who filled the prescriber's self-prescribed controlled-substance Rx when something like this happens, and especially if someone is killed?