Nicotine is used to treat pain (9/16/97)
Although smoking tobacco is harmful to your health, under certain circumstances the nicotine in tobacco may be a beneficial drug. While the stabbing pain caused by nerve damage is only partially relieved by most pain medications, it is possible that in the future a medication analogous to nicotine will block this type of pain altogether.
Christopher Flores, PhD, assistant professor of endodontics and pharmacology at The University of Texas Health Science Center in San Antonio, is examining nicotine and nicotinic compounds for use in treating pain.
"It's been appreciated for more than fifty years that nicotine has pain relieving effects," Dr. Flores said, "but it also has adverse side effects, such as tolerance to the drug.
"Some new analgesic compounds are being developed, and research has identified novel uses for these drugs," Dr. Flores said. ''These factors point to a new direction that may overcome many of the side effects of classical analgesics and lead to the development of drugs which are excellent pain killers."
The researcher explained that much of the renewed interest in nicotine and nicotinic compounds is coming from the recent synthesis of an alkaloid that originally comes from the skin of an Ecuadorian frog and is up to 200 times more potent than morphine. Similar to nicotine, this frog venom is a potent pain killer.
"We are working on cellular and molecular studies, trying to understand pain and the transmission of pain," Dr. Flores said. "If we can determine which substrates--receptors or signal transduction mechanisms- -are involved in pain transmission, and if we could design drugs active only on those particular pathways, then maybe we could provide a novel analgesic that would be both safe and effective."
Dr. Flores said that some of the best known drugs have side effects, such as tolerance or respiratory depression, which precludes long-term treatment in effective doses.
"It isn't that nicotinic drugs don't have side effects,'' Dr. Flores said, "but early evidence suggests that these compounds are at least as potent as opiates, or synthetic narcotics, and when given in analgesic doses, they have fewer adverse side effects."
How did a classical pharmacologist end up in endodontics?
"The relationship is mutually beneficial. Tooth pulp is rather unique. Virtually all the nerves in tooth pulp are pain conveying and any stimulus seems to result in the sensation of pain, which makes tooth pulp a great model tissue in which to study pain."
Dr. Flores thinks this is a very exciting time because a number of technologies are working together to provide tools needed to come up with the next generation of analgesic compounds.
"Neuropathic pain, for example, is an incredibly debilitating, chronic pain state and typically difficult to treat with current drug therapies," he said. "Now that we are becoming aware of the factors which contribute to neuropathic pain, we can go about designing drugs to block them.
"Some great information has recently come out about a different kind of sodium channel, a membrane protein through which ions travel that is upregulated during some types of pain. This channel is insensitive to traditional, local anesthetic drugs, unlike sodium channels we were aware of earlier. Now that we know this, we may be able to block those channels to prevent pain," Dr. Flores said.
Originally from California, Dr. Flores earned his doctorate at Georgetown University in Washington, DC, and then moved on to the National Institutes of Health, where he was a research biologist and then a staff fellow. Most recently, Dr. Flores spent three years at the University of Minnesota.
Contact: Jan Elkins (210) 567-2570