It is not only Providers exchanging information on pts it is also pharmacies. If there is a red flag that pops up on a person's file in a pharmacy they will call the Dr's office and inform them of the behavior (Dr shopping, multiple refills, possibly forged Rxs.) The Dr's office, in turn, may do a search of local pharmicies to see if the pt is also filling meds there, and the pharmacy will give then the history on the pt and what Dr's prescribed how much and when. Then the pt could possibly be discharged from the practice based on this information or if there is enough evidence the pt could face the police.

This also may happen even without the pharmacy calling. If there is suspicion of drug seeking the Doc will have an assistant do a seach of pharmacies as stated above.