Final answer:
Non-resident pharmacies must maintain records of controlled substances dispensed in Louisiana for regulatory compliance, to monitor and prevent illegal diversion, and to help with public health monitoring.
Step-by-step explanation:
A non-resident pharmacy must keep records of any controlled substances dispensed to residents of LA so that they can ensure compliance with federal and state regulations, monitor controlled substance dispensation, and facilitate audits or investigations by regulatory bodies. Keeping detailed records helps pharmacies track the quantities of controlled substances dispensed, prevents the illegal diversion of these drugs, and serves as a tool for public health and safety monitoring.