Final answer:
The logbook of controlled substances dispensed each day in an inpatient pharmacy must be retained for a minimum of two years as per DEA regulations, but local laws may extend this duration.
Step-by-step explanation:
In an inpatient pharmacy, the logbook of controlled substances dispensed each day must be retained for a specific period of time as mandated by federal and state regulations. These regulations can vary, but generally, the Drug Enforcement Administration (DEA) requires that records of controlled substances be kept for at least two years. Pharmacy professionals must ensure compliance with these regulations to maintain accurate tracking and prevent misuse of controlled substances. The duration for record retention may differ based on local laws, so it is imperative for pharmacy staff to be knowledgeable about both federal and their respective state regulations.