Analgesia

The first phase in the development of new analgesics came with the development of narcotic blockers used to help drug addicts who overdose on a narcotic. Since these drugs have the ability to block the effects of morphine, they are called antagonists. They do not, however, provide any pain relief.

A second generation of narcotic antagonists are called agonist-antagonist analgesics. An agonist drug does provide pain relief by occupying receptor sites that block pain signals to the brain. The new group of agonist-antagonist medications show improved performance over morphine for providing pain relief, with fewer side effects and less chance of addiction.

The present challenge for medical science is to find medicines that are as effective as the opiates and morphine for relieving pain but do not have their side effects. Recent research on the brain has uncovered how endorphins and other related brain chemicals work, and provides hope for improved analgesic drugs.