Friday, March 21, 2008

Old drug, new use? Naltrexone in tiny doses shows promise in treating autoimmune diseases

By Bill Kettler
Mail Tribune
March 10, 2008

When Destiny Marquez finds a good thing, she wants other people to know about it.

These days the Medford woman has been talking to anyone who will listen about a drug called naltrexone. It's been widely used to treat opiate addiction, but that's not what captured her interest.

Marquez came across naltrexone while she was trying to help her father, Bentley Lyon, who's been struggling with Parkinson's disease for 18 years. His symptoms had been increasing, and he started to decline rapidly after suffering a stroke during surgery.

A friend had told Marquez that she'd heard some Parkinson's patients were getting relief from their symptoms by taking extremely low doses of naltrexone, or LDN. Marquez and her mother, Elizabeth, balked. Although the drug had been tested and approved by the federal Food and Drug Administration for addiction treatment, it had never been tested for treating Parkinson's.

"We said 'No,' " Marquez recalled.

When Bentley's condition continued to deteriorate, mother and daughter asked him to give LDN a try. By then they had done some research on their own, and learned that the drug was gaining favor not only among Parkinson's patients, but also as a treatment for other diseases, including multiple sclerosis and Crohn's disease.

Marquez said her father started taking 3 mg a day late in 2004, far less than the 50 mg that's prescribed for addiction treatment.

"It was like a miracle," she recalled.

Marquez said the spasticity in her father's left leg disappeared over several days, and his caregiver said he stopped complaining about back pain.

Speech is difficult for Bentley, 78, a former Marine and marathon runner who worked as a forester and wrote two mystery novels, but he said LDN "stopped the progression" of his symptoms. Naltrexone apparently works by stimulating the body's own immune system, said Dr. Ian Zagon, a professor of neural and behavioral sciences at Pennsylvania State University.

"It's very simple," he said, "but it took a while to figure out."

Zagon said research over the past two decades indicates the body's immune system is orchestrated by its own naturally produced internal opioids. Large doses of naltrexone block the body's opioid receptors, eliminating the high derived from drugs. In extremely small doses, however, naltrexone seems to block the opioid receptors just long enough to prompt the body's hormone system to produce more of its own natural endorphins, which somehow encourages the immune system.

"We're working with the body's own chemistry," Zagon said. "This has nothing to do with chemotherapy."

The drug's off-label use began to grow just as the Internet became a major source of information exchange. There's now an LDN home page (, a Wikipedia entry, and forum pages where people exchange information and their own experiences with the drug.

Naltrexone's efficacy for Parkinson's or other autoimmune diseases could be established by subjecting it to a new round of clinical trials, the same rigorous, expensive, time-consuming studies that were performed when it was approved for addiction treatment. Unfortunately, there's little incentive for drug manufacturers to spend the money. Naltrexone has gone generic, and lost the patent protections that would make it a profitable drug for treating autoimmune diseases.

"It doesn't behoove the pharmaceutical companies to develop it," Zagon said.

As a generic drug, it's also incredibly cheap. Most patients can get it for about $1 a day.

Zagon would like to see someone provide the funding for new clinical trials for LDN, but in the meantime, some studies are already under way. The National Multiple Sclerosis Society has funded a study that will look at high- and low-dose naltrexone treatments in mice with a disease much like multiple sclerosis, and the National Institutes of Health has funded a phase II trial using LDN in patients with Crohn's disease. Phase II trials involve as many as several hundred people, but they fall short of the randomized phase III trials in which some people get the drug and others do not.

Marquez has seen how the drug has helped her father, and she hopes one day someone will do the research that will determine its efficacy.

"We're not the only family talking about this," she said. "We're trying to share this information because it buys you time.

"We've got to tell the world this drug is incredible."

Destiny Marquez can be reached by e-mail at:

Reach reporter Bill Kettler at 776-4492 or e-mail: