What must a pharmacist do if the remainder of a partial C2 fill cannot be supplied within 72 hours?

When a pharmacist faces a situation where the remainder of a partial fill for a Schedule II controlled substance cannot be supplied within the required 72 hours, the correct action is to notify the prescriber. This step is necessary because, according to federal regulations, a Schedule II prescription can only be filled as originally prescribed. If the pharmacist cannot fill the remainder of the prescription within the allowed timeframe, they must inform the prescriber to decide the next steps. The prescriber may need to issue a new prescription if the patient still requires the medication.

While it may seem important to contact the patient or notify the DEA, these actions do not align with the required protocol in this situation. The patient does not need to be contacted directly, as the responsibility falls on the pharmacist to ensure that the prescription is filled correctly in accordance with the prescriber's instructions. Notifying the DEA would not be applicable in this instance unless there were concerns involving the handling of controlled substances. Filing a report is also unnecessary in this context, as the focus is on resolving the prescription issue with the prescriber. Thus, the correct choice highlights the critical aspect of communication with the prescriber in maintaining compliance with controlled substance regulations.