Restless Legs Syndrome and Related Disorders - Medications

(Page 2)

Levodopa and Other Dopaminergic Drugs

Dopaminergic drugs increase the availability of the brain chemical dopamine and are the first-line treatment for severe RLS and PLMD. These drugs significantly reduce the number of limb movements per hour and improve the subjective quality of sleep. Patients with either condition who take these drugs have experienced up to 100% reduction in symptoms. However, these drugs, which are ordinarily used for Parkinson's disease, can have severe side effects. They do not appear to be as helpful for RLS related to hemodialysis as RLS from other causes. Dopaminergic drugs include dopamine receptor agonists and dopamine precursors.

Dopamine Receptor Agonists. Dopamine receptor agonists (also called dopamine agonists) are increasingly being used as alternatives to L-dopa. Because they have fewer side effects than L-dopa, including rebound effect, and augmentation, these drugs may be used on a daily basis. They have been shown to relieve symptoms in up to 70 - 90% of patients. Dopamine agonists can be categorized as ergot-derived (such as pergolide, cabergoline) or non-ergot derived (such as pramipexole, ropinirole). The newer non-ergotamine derivatives may induce fewer side effects than ergot-derived drugs. Studies on these medications report the following:

• Ropinirole (Requip) is a non-ergotamine dopamine agonist. Approved in 2005, ropinirole is the first and only drug approved specifically for treatment of moderate-to-severe RLS (more than 15 RLS episodes a month). Side effects are generally mild but may include nausea, vomiting, drowsiness, and dizziness.
• Pergolide (Procalamine) is as effective as carbidopa-levodopa and has fewer side effects, though nausea, dizziness, and nasal stuffiness are common. It also seems to produce fewer of the rebound and augmentation effects of levodopa, particularly at higher doses. Benefits persist for at least a year.
• Pramipexole (Mirapex) is showing good results in clinical trials for improving symptoms and quality of life in patients with RLS. A long-term, follow-up study showed the drug continued to be effective for RLS, even after 7 months of use. However, some research suggests that RLS symptoms may rapidly worsen when the drug is discontinued. The most common side effects of pramipexole include nausea, headache, and tiredness.
• Cabergoline (Dostinex) is also showing promise in clinical trials. In one study, cabergoline was used for RLS after levodopa had either failed or resulted in increased symptoms. Patients in the study reported relief or freedom from symptoms after 4 weeks of use. A 2006 study indicated that a single evening dose of cabergoline improved both day and nighttime limb movements, and sleep disturbances.