The cause of fibromyalgia is unknown; however, it is believed to involve a combination of genetic and environmental factors with half the risk attributed to each. The condition runs in families and many genes are believed to be involved.
Agonist: A substance that acts like another substance and therefore stimulates an action. Agonist is the opposite of antagonist. Antagonists and agonists are key players in the chemistry of the human body and in pharmacology.
Answer: Agonist-antagonist medicines represent a class of opiod medications that bind to both a receptor that produces pain relief, which is the agonist portion, and bind to another receptor that does not produce a physiological effect, which is the antagonist portion.uprenorphine or Buprenex is another example of a mixed agonist-antagonist medicine that is growing in use due to its ability to produce good pain relief, its potential for reduced risk of respiratory depression, and its ability for use as a maintenance drug for opioid-dependent patients.