It's your license so yes there should not be a legal requirement to stock anything. If your company requires you to stock something as a condition of employment you are free not to accept that condition of employment and not work for them.
In my specific situation I had Oxycontin, oxycodone/ASA, oxycodone/APAP along with MSER, fentanyl, hydromorphone, methadone, Kadian, Avinza, Opana ER, oxymorphone IR and even meperidine too so there were many options to cobble together a pain regimen. MCK and/or CVS cap ordering of oxycodone presentations so if I ordered plain oxycodone that would take away from the other presentations