Please correct me if I'm wrong, but I don't think prison pharmacists have much (if any) interaction with the patients. They might be asked to see one if the prison has an infirmary, but otherwise, they're in the back somewhere filling weekly orders, just like any other long-term facility.
Having worked in pharmacies that serviced county jails, yes, the technician dropped the bags off there every week, but that was at the clinic and they were locked up.