A research team at Duke University has discovered a potential new class of small-molecule drugs that simultaneously block two sought-after targets in the treatment of pain.
These proof-of-concept experiments, published June 1 in Scientific Reports, could lead to the development of a new drug to treat conditions including
- skin irritation and itching,
- jaw pain, and
- abdominal pain stemming from the pancreas and colon.
I find it odd that this drug treats pain only of specific types and in specific locations.
In the new study, the researchers initially aimed to develop more effective blockers of TRPV4, a molecule their previous research had shown transmits skin irritation elicited by sunburn, and painful sensations coming from the head and face.
Liedtke and his Duke collaborator Farshid Guilak used a prototype TRPV4 blocker in a 2009 study and then set out to develop more potent versions.
Compared to the prototype, one of the new candidate drugs, called “16-8,” worked 10 times more effectively in cells with active TRPV4 that are key for the development of osteoarthritis. It also worked well in another cell type involved in nerve cell injury, stroke and epilepsy
But to their surprise, when assessing the specificity of 16-8, the scientists discovered that it also blocked TRPA1, which is a promising target in pain and itch research.
Both TRPV4 and TRPA1 are members of the family of TRP ion channels, which function in sensory nerve cells to directly sense painful stimuli. Other research groups are now targeting these channels in clinical trials for pain relief.
Liedtke sees potential for the 16-8 drug to treat osteoarthritis and other types of joint pain as well as head, face and jaw pain.
In general, it might also treat aches radiating from internal organs or resulting from nerve cell injury.
Reference Article: Small molecule dual-inhibitors of TRPV4 and TRPA1 for attenuation of inflammation and pain, Patrick Kanju, Yong Chen, Whasil Lee, Michele Yeo, Suk Hee Lee, Joelle Romac, Rafiq Shahid, Ping Fan, David M. Gooden, Sidney A. Simon, Ivan Spasojevic, Robert A. Mook, Rodger A. Liddle, Farshid Guilak & Wolfgang B. Liedtke, Scientific Reports, doi: 10.1038/srep26894, published online 1 June 2016.
Such a drug that works in previously unknown ways could cause very complex and difficult to find, yet drastic, side effects. For the first few years, every patient will be a test subject to see if there are long term problems with it.
I anticipate this drug to be used long before it is adequately tested in the blind rush to use a pain medication that is not an opioid. This seems to be the main criteria these days, not pain control.