Treating pain with opioid pills can work well initially, but many Americans end up on high doses of oral medications for years on end. At some point, they may be doing little more than treating withdrawal that sets in between doses.

Medical device maker Medtronic is rolling out a new system that it said can wean patients entirely off pain pills by gradually transitioning them to an implantable medical device called the SynchroMed II, which dispenses tiny doses of opioids directly into spinal fluid.

In recent years the Food and Drug Administration has been encouraging the development of new therapies to treat pain without using oral opioid drugs, calling opioid addiction "an immense public health crisis." Prescription opioids, such as oxycodone and fentanyl, belong to the same class of drugs as heroin and morphine.

Medical device companies in Minnesota have responded to the call with many different options, including pacemaker-like "neurostimulators" that interrupt pain signals and devices that temporarily or permanently disable nerves. Each carries different risks, benefits and costs compared to pain pills.

This week Medtronic is emphasizing the potential of its SynchroMed II implantable drug pump, in combination with a new treatment paradigm called the "control workflow," to combat opioid misuse and overuse.

The SynchroMed II drug pump has long been available to patients in the U.S. Prescriptions for the device were restricted for several years by a federal consent decree, but those restrictions have since been lifted.

What's new is the control workflow, which can be used to reduce and then eliminate pain pills from a patient's life. The workflow describes a process to identify and then treat appropriate patients — especially those with primary back pain.

The workflow calls for people with chronic pain to slowly decrease their pain pill intake until they can take a complete "holiday" from the pills for up to 6 weeks. Once fully tapered, they start receiving smaller doses of liquid opioid drugs from the SynchroMed II.

The device pumps small doses of drugs from a reservoir in the machine through a thin tube implanted near the spine. The device has FDA approval for long-term delivery of morphine sulfate sterile solution and ziconotide sterile solution for chronic pain, when oral drugs haven't worked.

"There is a significant unmet need in chronic pain, and device-delivered options are underutilized for appropriate patients, so we continue to innovate to maximize the value of proven treatments," said Charlie Covert, general manager of Medtronic's targeted drug delivery business, in a news release. "We will continue to partner with stakeholders to provide clinical guidance that helps physicians understand when to consider device-delivered treatments."

Medtronic's clinical evidence for using SynchroMed II to eliminate oral pain drugs predates the new workflow.

A 2015 study of medical claims for 389 chronic-pain patients found that 51 percent were able to stop taking pain pills within a year of starting to use the drug pump. Those who stopped pain pills between four and seven months after using the pump had about $5,000 less in health care and drug expenditures.

Medtronic's new patient workflow is designed to build on those results by identifying chronic pain patients best suited for the SynchroMed therapy.

"The workflow is especially helpful for patients who may be on high doses or cannot tolerate systemic opioids, or for those who are not finding pain relief with systemic opioid therapy," said John A. Hatheway, a Spokane, Wash., pain physician and paid Medtronic consultant. "By placing the medication at the source of the pain, we can often provide better pain relief with fewer side effects at a fraction of the oral dose."