Prescription Monitoring Program
A prescription monitoring program (PMP) typically refers to a state-run program (in the United States) that serves as a registry to track prescriptions for controlled substances. These serve physicians who want to know if his or her patient is receiving similar medications from other physicians. Pharmacies that dispense controlled substances are usually required to register the filling of such prescriptions with a state-run database.
More info on wikipedia. The best way to find the right website is to type in Google “Prescription Monitoring Program + the name of the state you are practicing in”.