New hope to beat nerve pain

RESEARCH investigating antidepressants and nerve pain helps open up the possibility of a new class of better drugs, a leading Geelong doctor says.

Researchers have shown how tricyclic antidepressants (TCAs) work against nerve pain, also known as neuropathic pain, paving the way for further research and therapies.

Although TCAs are listed as drug treatments of choice for neuropathic pain in the Australian Medical Handbook, how they work to limit pain has not been fully understood, until now.

Recently published in RSC Medicinal Chemistry, researchers from the CSIRO, University of Queensland and Monash University used a neuroblastoma cell line to show how 11 TCAs and two closely related drugs blocked pain, and identified which ones were most effective.

“Though suspected, this is the first time such a broad set of TCAs have been proven to block these channels,” said CSIRO scientist and lead author Adjunct Professor Peter Duggan.

“Knowing how pain impulses are inhibited by TCAs is expected to lead to new and improved treatment options for people suffering neuropathic pain. And the more we work in this space, the more our science opens up the possibility of effective pain therapies, free of any potential sideeffects.”

Deakin University Clinical Associate Professor Michael Vagg, also dean of the Faculty of Pain Medicine at the Australian and New Zealand College of Anaesthetists, said nerve pain was highly disabling and ruined lives.

Usually chronic, it can be experienced for reasons such as cancer, diabetes, trauma, infection, and multiple sclerosis.

It is estimated to affect one in 20 Australians.

Symptoms vary from shooting or throbbing pain, burning, freezing or electrical shock sensations, tingling, itchiness, oversensitivity or numbness.

“The best current treatments only work to a useful degree on every third or fourth person who receives them,” said Geelong-based Prof Vagg.

“Tricyclic drugs have been used for decades in treating nerve and musculoskeletal pain and are still the most likely drugs to help.

“We have not had any really effective new treatments for nerve pain for a long time and this work opens up the possibility of designing a new class of drugs with improved safety and effectiveness.”