"The existence of a PDMP [prescription drug monitoring program] within a state, however, appears to increase drug diversion activities in contiguous non-PDMP states. When states begin to monitor drugs, drug diversion activities tend to spill across boundaries to non-PDMP states. One example is provided by Kentucky, which shares a boundary with seven states, only two of which have PDMPs—Indiana and Illinois. As drug diverters became aware of the Kentucky PDMP’s ability to trace their drug histories, they tended to move their diversion activities to nearby nonmonitored states. OxyContin diversion problems have worsened in Tennessee, West Virginia, and Virginia—all contiguous non-PDMP states—because of the presence of Kentucky’s PDMP, according to a joint federal, state, and local drug diversion report."

Source

General Accounting Office, Prescription Drugs: State Monitoring Programs Provide Useful Tool to Reduce Diversion (Washington, DC: Government Printing Office, May 2002), GAO-PO-634.