Researchers learn how antidepressants treat nerve pain

Australian scientists have discovered how antidepressant medications work against nerve pain, paving the way for new treatments.

In a study published in the journal of RSC Medicinal Chemistry, a team from the Commonwealth Scientific and Industrial Research Organisation (CSIRO) revealed for the first time how tricyclic antidepressants (TCAS) treat nerve pain.

TCAS are commonly prescribed for nerve pain without an understanding of how or why they are effective until the CSIRO team identified the responsible mechanisms.

"This study provides the most comprehensive evidence to date that supports the notion that the blockade of neuronal calcium ion channels by TCAS is at least partially responsible for their analgesic effect," according to the abstract in the journal.

Peter Duggan, a CSIRO scientist and leader of the research, said he was hopeful the findings would lead to the development of a new type of drug to treat nerve pain without any side effects.

"These types of antidepressants are commonly used to treat pain, so we know they can be effective, but until now we haven't understood what is happening at a cellular level," he said in a media release on Tuesday.

"Now we understand how they work, the next step is to look at developing whole new therapies that target the same nerve receptors and eliminates any potential side-effects," he said.

Nerve pain – also known as neuralgia or neuropathic pain – affects approximately one in 20 Australians. It occurs when nerves that carry sensations to the brain are damaged or affected by a health condition such as cancer, diabetes, infection or multiple sclerosis (MS).

Symptoms of nerve pain can range from shooting or throbbing pain to burning or freezing sensations, tingling, itchiness, numbness or oversensitivity.

"Nerve pain is highly disabling and ruins lives. The best current treatments only work to a useful degree on every third or fourth person who receives them," Michael Vagg, dean of the Faculty of Pain Medicine at the Australian and New Zealand College of Anaesthetists, said.

"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."