When conducting a controlled substance inventory, which of the following must be included?

When conducting a controlled substance inventory, it is essential to include drugs stored in a warehouse for the registrant at a different location because these substances are still under the ownership and control of the registrant. The regulations governing controlled substances require that all inventory be accurately accounted for, regardless of where the drugs are physically located, as they are part of the registrant's stock. This ensures compliance with federal and state regulations surrounding the handling of controlled substances, which aims to prevent mismanagement and potential misuse.

Including items that are stored at a different location helps maintain an accurate and comprehensive record of all controlled substances held by the registrant, thereby mitigating the risk of discrepancies during audits or inspections. In contrast, the other options do not qualify as they pertain either to inventory that is not yet owned by the pharmacist (such as drugs ordered but unpaid for), items that are no longer in active use (like returned drugs), or those that have been delivered but not yet integrated into the inventory system. These factors do not contribute to the current count of controlled substances required for compliance purposes.