Preliminary tests of the anesthetic in rats show it effectively blocked pain without causing complete loss of movement in the targeted areas.
Researchers say the experimental anesthetic works by selectively blocking pain-sensing nerve cellsB without disrupting other nerve cells that control movement or nonpainful sensations. If the results are confirmed in humans, the method could be used in procedures ranging from knee surgery to tooth
"Eventually this method could completely transform surgical and post-surgical analgesia, allowing patients to remain fully alert without experiencing pain or paralysis," says researcher Clifford Woolf of
Massachusetts General Hospital in a news release. "In fact, the possibilities seem endless. I could even imagine using this method to treat
itch, as itch-sensitive neurons fall into the same group as pain-sensing
Researchers say that although current anesthetics are highly effective, they
also come with significant side effects, such as unconsciousness in the case of general anesthetics and temporary loss of sensation or paralysis in local anesthetics.
Hot Pepper Kills Pain
In the study, published in Nature, researchers combined a derivative
of the common anesthetic lidocaine with capsaicin, the ingredient that makes
chili peppers hot.
They injected the chemicals into the paws of rats and measured their ability
to sense pain from a heat source. The animals were able to tolerate much more heat than usual.
Then, they tried injecting the anesthetic near the sciatic nerve of the rats
and pricked their paws with nylon probes. The animals seemed to ignore the
painful prick, but continued to move normally and responded to other stimuli.
Aside from use in surgical procedures or childbirth, researchers say the
experimental drug may also eventually lead to more effective chronic pain
By Jennifer Warner
Reviewed by Louise Chang
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