How long must a C2 prescription be filled after a partial fill for a regular patient?

When a controlled substance prescription for a Schedule II drug is partially filled, federal regulations require that the remaining quantity must be filled within 72 hours from the time the prescription was issued. This is intended to ensure timely access to medications for patients who may need ongoing treatment, while also providing a measure of control to prevent misuse of these potent substances.

If the remaining quantity is not dispensed within this 72-hour window, the pharmacist cannot fill the remainder of the prescription, and the patient would need to obtain a new prescription for the remaining quantity. It is also essential to keep in mind that individual state laws may differ, but when it comes to federal regulations, the 72-hour rule is the standard for Schedule II prescriptions.