It appears to be more powerful and to be better tolerated by patients than other such drugs. About one million adults in North America are afflicted by Parkinson's disease, in which several hundred thousand cells in a tiny region of the brain die for unknown reasons. This pea-sized part of the brain produces dopamine, a neurotransmitter that's key to the control of movement. Parkinson's, which afflicts adults ranging from ages 40 to 80, results in uncontrollable tremors and shaky, stiff, and slow movements. The condition of patients slowly declines over a period of years or even decades, with the hardest-hit unable even to stand or walk.
Current drugs reduce the symptoms, but their effects wane with time.
Pramipexole dihydrochloride is a member of a family of drugs known as dopamine agonists, which mimic dopamine and stimulate brain cells just as the natural neurotransmitter would. Adding a powerful new stablemate to the range of drugs already available will improve doctors' ability to find the best mix for each individual patient, Dr. Kieburtz says. The drug appears to be more effective than other dopamine agonists in reducing tremors and movement problems. In addition, unlike current drugs, pramipexole dihydrochloride does not cause lightheadedness resulting from a noticeable drop in blood pressure when a patient stands up. Dr. Kieburtz says that's probably because the drug targets the specific dopamine receptor involved in Parkinson's disease more precisely.