Dopamine agonists in the brain have a similar effect to levodopa since they bind to dopaminergic postsynaptic receptors. Dopamine agonists were initially used for patients experiencing on-off fluctuations and dyskinesias as a complementary therapy to levodopa, but they are now mainly used on their own as an initial therapy for motor symptoms with the aim of delaying motor complications. When used in late PD, they are useful at reducing the off periods. Dopamine agonists include bromocriptine, pergolide, pramipexole, ropinirole, piribedil, cabergoline, apomorphine, and lisuride.