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.
antagonist: a compound that blocks or inhibits the action of a neurotransmitter. direct-acting antagonist (aka receptor blocker): binds to the same receptor population as an agonist but fails to activate the target receptors.competitive antagonist: competes with an agonist for the same receptor population.ntagonist: a compound that blocks or inhibits the action of a neurotransmitter. direct-acting antagonist (aka receptor blocker): binds to the same receptor population as an agonist but fails to activate the target receptors.