Three studies, scheduled for presentation in San Diego during next weeks annual meeting of the American Academy of Neurology, showcase potential new treatments for people with Parkinsons disease.
One study dealt with orthostatic hypotension, which people with Parkinsons might experience when standing up and which can lead to dizziness, fainting and falls. The problem, which affects about 18% of people with the disease, occurs because the autonomic nervous system fails to respond to changes in posture by releasing enough norepinephrine.
In the study, 225 people were randomized to receive either eight weeks of stable dose treatment with a placebo or the drug droxidopa, which converts to norepinephrine. After one week of stable treatment, those who received the drug had a clinically meaningful, two-fold decrease in symptoms of dizziness and lightheadedness, when compared with placebo. They also had fewer falls: 0.38 per patient per week during the study duration, compared with 1.73 falls for those receiving a placebo. (See a PDF of the study abstract at http://www.aan.com/globals/axon/assets/10711.pdf.)
A second study looked at a new course of treatment for people who have been taking levodopa for several years. As each dose wears off, people experience longer periods of time when motor symptoms do not respond to levodopa.
For the study, 420 people who were experiencing an average of six hours of “off” time per day received a placebo or one of four dosages of the drug tozadenant in addition to their levodopa for 12 weeks. People receiving two dosages had slightly more than an hour less “off time” per day at the end of 12 weeks than they had at the start of the study. They also did not have higher rates of troublesome involuntary movements that can occur during dyskinesia (“on” time). (See a PDF of the study abstract at www.aan.com/globals/axon/assets/10712.pdf.)
A third study looked at 321 people with early Parkinsons disease whose symptoms were not well-controlled by a dopamine agonist drug.
For the 18-week study, participants took either the drug rasagiline or a placebo in addition to their dopamine agonist. At the end of the study, those taking rasagiline had improved by 2.4 points on a Parkinsons disease rating scale. In addition, rasagiline was well-tolerated, with adverse events similar to placebo. (See a PDF of the study abstract at www.aan.com/globals/axon/assets/10710.pdf.)
“All of these treatments are promising news for people with Parkinsons disease,” Robert A. Hauser, MD, MBA, of the University of South Florida in Tampa and a Fellow of the American Academy of Neurology, said in a news release. Hauser was involved in all three studies.