Cycloset belongs to a group of medications known as ergot alkaloids. It works as a dopamine receptor agonist, which means that it binds to and stimulates dopamine receptors. Dopamine is a neurotransmitter (a chemical that transmits signals between nerves).
It is not entirely clear how Cycloset works to control blood sugar, but it is thought that stimulating dopamine receptors in the brain at certain times of the day "resets" the biological clock and improves metabolism. It is thought that seasonal changes in the metabolism of wild animals are due to similar mechanisms.
For years, bromocriptine (the active ingredient in Cycloset) has been used to treat Parkinson's disease, acromegaly (a growth disorder), and hyperprolactinemia (a hormone disorder). Only recently has it been approved for treating diabetes.
This medicine has not been approved for use in children. However, other forms of bromocriptine are approved for treating prolactin-secreting tumors (which cause hyperprolactinemia) in children. Therefore, there is some basic safety information available about the use of bromocriptine in children.
On occasion, your healthcare provider may recommend Cycloset for something other than the uses discussed in this article. At this time, however, there are no universally accepted off-label uses for Cycloset (although there are off-label uses for other forms of bromocriptine).