Improving Levodopa Bioavailability and Consistency of Absorption through Co-administration of GSK962040
Repositioning Drugs for PD, 2012
Parkinsonís disease (PD) often results in slower than normal emptying of food and medications from the stomach. This delayed gastric emptying is estimated to affect 50-90 percent of PD patients. Levodopa, the gold standard PD medication, is absorbed when it reaches the upper intestine. If gastric emptying is delayed, levodopa may be erratically absorbed, resulting in slower relief of symptoms and "on-off" fluctuations. GSK962040 is a medication that, in research studies, has been shown to increase the speed at which the stomach empties. This project will study the effects of GSK962040 in people with Parkinsonís and delayed gastric emptying.
Up to 70 people with Parkinsonís and confirmed delayed gastric emptying will be randomly assigned to receive either GSK962040 or an inactive placebo tablet. Patients will take the tablets once daily for a total of eight days. Neither the participants nor the study doctors will know which tablet the patient has received until the end of the project. Participants will be assessed regularly before, during and after receiving the study medication. Researchers will measure participantsí levodopa levels in the blood, changes in gastric emptying rates and motor (movement) symptoms to determine if GSK962040 can increase the speed of gastric emptying, improve levodopa absorption, improve the effect of levodopa on the motor (movement) symptoms of Parkinsonís and improve the gastrointestinal symptoms that can result from delayed gastric emptying.
Relevance to Diagnosis/Treatment of Parkinsonís Disease:
If this medication is shown to increase the speed of gastric emptying, and as a consequence increase rates of levodopa absorption, it has the potential to be an effective treatment to improve gastrointestinal symptoms and enhance and extend the effects of levodopa in people with Parkinsonís.
By increasing the rate of gastric emptying in people with Parkinsonís, it is anticipated that GSK962040 will increase rates of absorption of levodopa. Quicker absorption of levodopa will shorten the period of time between taking the medication and seeing improvement in symptoms. The period of time for which levodopa improves movement (ďonĒ time) is expected to increase when GSK962040 is also taken. Additionally, the symptoms that can result from delayed gastric emptying (nausea, feeling bloated or full quickly after meals) are expected to improve in people taking GSK962040.
In total 19 patients received the inactive placebo and 37 received 50mg of the study medicine GSK 962040, also called Camicinal. Those patients who took Camicinal showed an improvement in ďonĒ time where levodopa improved motor symptoms. Additionally, symptoms that can result from delayed gastric emptying such as constipation were slightly improved among some taking Camicinal Ė though a longer study is needed to confirm this. The study treatment was generally well tolerated throughout the study.
Professor of Movement Disorder Neurology at Institute for Ageing and Health, Newcastle University
Location: Stevenage, United Kingdom
Senior Lecturer in Gastrointestinal Physiology at University College Hospital & National Hospital for Neurology & Neurosurgery, London
Location: London, United Kingdom
Location: London, United Kingdom