Final answer:
A pharmacist facing an inability to fill the full quantity of a C2 prescription can partially fill it, noting this on the prescription and completing the fill within 72 hours. If unable to complete it within 72 hours, they must contact the prescriber for a new prescription.
Step-by-step explanation:
When a pharmacist in the United States encounters a situation where they are unable to fill the entire quantity prescribed on a Controlled Substance schedule II (C2) prescription, they have specific procedures to follow according to the Drug Enforcement Administration (DEA) regulations. The pharmacist may provide a partial fill of the C2 prescription if they cannot supply the full amount due to inventory limitations. However, they must note the quantity supplied on the front of the prescription and must fulfill the remaining balance within 72 hours. If the remaining balance cannot be supplied within that time frame, the pharmacist must notify the prescribing physician so that a new prescription can be issued for the remaining quantity. Moreover, in situations involving terminally ill patients or those in long-term care facilities, different rules may apply, allowing for additional partial filling allowances within a 60-day period from the issuance of the prescription.