A dentist's injection typically causes numbness for several hours. This experience could soon be history. Now, researchers have developed a combination of two agents which is able to specifically block pain without producing numbness or motor paralysis. The substance is composed of a normally inactive derivative of the local anesthetic lidocaine, called QX314, and capsaicin, the pain-producing substance in chili peppers. Capsaicin works by opening channels present only in pain fibers to allow the QX314 only into these cells, where it blocks their function.
More...