A review in the April issue of Nature Biotechnology describes research that is uncovering how pain is eased and that is leading to the development of drugs from marijuana, peppers, snails, and frogs that target particular pain-production centers in the body, among other things. One area of research involves the marijuana derivatives called cannabinoids. Like narcotics such as morphine and codeine, cannabinoids interfere with the area of the brain that perceives pain. Research at the University of California in San Francisco suggests that cannabinoids are more effective than opioids for some types of chronic pain. But cannabinoid research is controversial, and researchers are focusing on separating the compound's useful characteristics from the euphoric properties that make marijuana attractive to drug abusers.
Peppers are another hot area of pain research.
Investigators treating patients with overactive bladders and a diabetes-related condition in which people experience pain in their extremities are working with a derivative of capsaicin, the main ingredient in hot peppers. Capsaicin itself is a pain reliever, but researchers say the derivative seems to have fewer side effects. The lowly snail is making headlines, too, with reports that venom from the cone snail, which lives on the coast of the Philippines, is a potent drug for relieving pain after surgery and some types of chronic pain. Then there is the poisonous Ecuadorian frog known as Epipedobates tricolor, which secretes a substance on its skin to kill predators. The substance possesses pain-relieving properties hundreds of times more potent than morphine, but is too poisonous for human use.