Such medications include nonergotoline drugs, such as pramipexole and ropinirole, as well as amantadine. Pramipexole has been shown to alleviate RLS symptoms such as motor restlessness, involuntary movements, and sleep difficulties in patients who have not responded to treatment with other DAs. Another adverse effect that has been reported in patients with Parkinson's disease is peripheral edema, which resolves when therapy is discontinued. Although food does not affect the drug's absorption, administering pramipexole with food may help minimize potential nausea. Because the drug is more selective for D 3 receptors than bromocriptine or pergolide, pramipexole may cause fewer episodes of OH than other DAs.
Side effects associated with pramipexole therapy include fatigue, stiffness, or dizziness.
The drug is primarily eliminated through urinary excretion. Ropinirole, another nonergotoline DA, stimulates D 2 and D 3 receptors, such as post-synaptic D 2 receptors in the caudate and putamen. As with pramipexole, ropinerole was approved by the FDA in 1997 for the treatment of Parkinson's disease. Food does not affect the medication' s absorption. When used to treat RLS, amantadine therapy is typically started at a dose of 100 mg daily, and titrated to a maximum dose of 300 mg per day.