The erectile dysfunction drug sildenafil (brand name Viagra) may be effective at relieving painful neuropathy, or nerve damage, in men with long-term diabetes, according to preliminary animal research recently published in the journal PLOS ONE. Approximately 60% to 70% of people with diabetes have some form of neuropathy, according to the National Institutes of Health.
In previous animal studies, sildenafil has been shown to improve blood supply to the sciatic nerve, which extends from the lower end of the spinal cord into the legs, and it has also been noted that people with diabetes taking the medicine have fewer symptoms of peripheral neuropathy (a type of nerve damage in the arms, legs, hands, and feet).
Many other drugs have been shown to be effective at relieving neuropathy in animal studies but have not demonstrated benefits in human trials. According to scientists at Henry Ford Hospital, this may be because these trials use young animals with an early stage of peripheral neuropathy, while most people used in studies of the condition are older and have an advanced form of peripheral neuropathy.
To better simulate the condition of participants in human trials, the researchers used 30 male mice with Type 2 diabetes that were 36 weeks old, which is roughly equivalent to middle age in people. Fifteen of the mice were given an oral dose of sildenafil every day for eight weeks, while the other fifteen mice served as a control group and were given the same amount of saline daily.
After performing a variety of nerve and function tests on both groups of mice, the researchers found that mice given sildenafil experienced noticeably improved neuropathy symptoms starting at six weeks after treatment compared with the mice that were given saline.
“Generally, young diabetic animals with an early stage of peripheral neuropathy are used to investigate various drug treatments. But patients with diabetes who are enrolled in clinical trials often are older and have advanced peripheral neuropathy,” notes lead study author Lei Wang, MD. “These data indicate that sildenafil improves neurological function even in middle-aged mice with long-term diabetic peripheral neuropathy.”
Although this line of research is still in the early stages, it has the potential to eventually lead to the development of a sildenafil-based treatment for long-term diabetic peripheral neuropathy, Dr. Wang added.
For more information, read the Henry Ford Health System press release “Erectile Dysfunction Drug Relieves Nerve Damage in Diabetic Mice” or see the study in PLOS ONE. And for more information about coping with painful neuropathy, see the article “Controlling Neuropathic Pain: Tips From an Occupational Therapist,” by Erica K. Jacques.