Wednesday, September 29, 2010

WPC Science Day Zero: Orthostatic Hypotension

From James Beck, Ph.D., Director of Research Programs

Yesterday, an industry-sponsored session for clinicians and scientists was held prior to the official start of 2nd World Parkinson Congress. Largely a review of current medical management of PD, the session included one tidbit that I found particularly interesting - a comment made by Mark Stacy, M.D.

He said that orthostatic hypotension, that is low blood pressure upon standing, is the most common, unrecognized symptom of PD.

Up to 40 percent of people with PD experience orthostatic hypotension. Drugs that are currently approved to treat hypotension, like midodrine, work, but may work too well. The problem for people with Parkinson's is that their blood pressure is generally normal upon lying down or sitting, and problematic only when standing. But midodrine is not “smart” enough to figure this out. So while the drug fixes the problem of low blood pressure when a person is standing up, it also acts when a person is not standing, often causing the problem of hypertension, i.e., high blood pressure.

A solution may be in the works in the form of a drug called droxipoda, approved in Japan and under clinical development in the US by Chelsea Therapeutics (one of the industry sponsors of the session). Much like levodopa, or L-DOPA, a dopamine precursor given to replace dopamine, droxidopa or L-DOPS, is a precursor to the neurotransmitter norepinephrine and is given as its replacement. Preliminary evidence from clinical trials, presented by Phillip Low, M.D. from the Mayo Clinic in Rochester, MN, seems to indicate that droxidopa may benefit orthostatic hypotension in PD without causing hypertension when a person is not standing.

It will be interesting to follow the fate of this drug as it is tested. Do you agree orthostatic hypotension is a problem? Are you waiting for better treatment for it? Let us know in the comment section below.


Anonymous said...

Persons with PD should be warned of the possibility of orthostatic hypotension, what it feels like, and what to do when the person feels faint, e.g., sit down immediately, even on the floor.

Anonymous said...

I am a YOPD with diagnosis in 2000, who has this happen once every 2-3 months. What I now know to look for is a feeling of extreme heat, then an uneasy feeling, followed by "seeing stars" - if I catch it in time, by putting my head between my legs - and getting fresh cool air - I can usuaully circumvent this. THe last time it occurred I was in a doctor's office - he took my blood pressure which was dangerously low. Replenish with liquid electrolytes helps as well.

Joy said...

My husband was diagnosed at age 57 with parkinsons. His initial problems presented with dementia - he totally failed the neuropsych exam and was immediately given SSD. He experiences orthostatic hypotension every couple of days. He also has times when his BP is high so he can't take a drug for either. Also, he has great dizzyness, probably one of his chief complaints and that started with the taking of medications. Originally the neurologist tried different meds but they all had the same dizzy side effect. He feels extra dizzy, light headed and unable to function or think when he has low blood pressure. I am wondering if his disease is actually msa or lewy body due to further information we've received. He had a pet scan which indicated lewy body disease but now the neurologist says that's not it. So why did the radiologist read it as lewy body. MSA had my husband as a guinea pig so to speak at a medical convention for msa so physicians could ask him questions and offer suggestions.