From the WPC Program Guide
James Parkinson’s Special Lecture
“Levodopa Over the Last 50 Years – Where We’ve Come and Where We Are Going”
Speaker: Dr. John G. Nutt, Professor of Neurology, Oregon Health & Science University
Learning Objectives:
- Understand the barriers to achieving constant brain levels of levodopa.
- Recognize the intricacies of converting levodopa into normal movement.
- Be familiar with different clinical responses to levodopa.
My Notes (which should be checked for accuracy by a doctor or researcher):
Levodopa converts in the brain to dopamine – the neurotransmitter that is dwindling in the brains of people with Parkinson’s.
The drug has been around for 50 years. The first patient, in August 1968, was given a bottle of pills that contained extremely high doses compared to what we take today. Apparently he got sick from it and returned the unused bottle of pills a year later.
Levodopa has a short half-life. After one to two hours it peaks and leaves the body. This may be true even for extended release formulations.
Unlike many other medicines, it’s absorbed through the small bowel, not the stomach.
There are two problems that levodopa faces:
- Absorption is erratic. Food impedes its absorption, especially protein.
- Getting it from the blood to the brain is sometimes impeded, too. Just because you get it to absorb into the blood via the small bowel, it doesn’t mean it will also automatically get into the brain.
Constant blood levels of levodopa do not guarantee a constant response in “on” behavior characteristics.
Mood and anxiety may be affected by levodopa. “Off” periods may worsen your anxiety, more than if you hadn’t taken the drug to begin with.
However, in an experiment comparing patients who took levodopa to patients who were given a placebo, the patients who had taken the drug were in better condition two weeks after they were taken off the drug, compared to the control group who never took the drug at all.
Final thoughts:
Levodopa will remain the priority Parkinson drug for the next 50 years.
Researchers need to develop a better continuous delivery system.
Researchers also need to learn how to adjust dosage release in response to motor function during the day.
That’s the challenge: maintaining a constant level of levodopa in the brain.
If you attended this lecture and wish to add to my notes or correct my errors, please do so in the comment box below. You can also leave a comment if you just want to respond…or vent.
