Nathan Freed Wessler of the ACLU writes:

I will be in federal district court in Oregon today for oral argument in the ACLU’s challenge to the Drug Enforcement Administration’s practice of obtaining Oregon patients’ confidential prescription records without a warrant. We represent patients and a doctor whose prescriptions are tracked in the Oregon Prescription Drug Monitoring Program (PDMP), a state database intended as a public health tool to help doctors and pharmacists avoid and treat drug overdoses and abuse by their patients. Although Oregon law requires police to get a probable cause warrant from a judge before requesting PDMP records in an investigation, the DEA refuses, and instead uses administrative subpoenas to request the records. Unlike a warrant, those subpoenas involve neither prior approval of a judge nor a showing of probable cause.

Read more on ACLU.  You can find more information on the case as well as case files here.