Ask the Doctor Moderators Posts:
19-January 07 LocationUniversity of Florida Posted Today, 01:08 PM
Dear forum members,
Forty percent or more of PD patients suffer from orthostatic hypotension (dizziness when standing, passing out, etc.). Dr. Lowe from the Mayo clinic presented some very promising results at the World Congress for PD in Scotland last week.
There is a drug called droxidopa in trials; which is a hydroxylated form of levodopa.
Though this may be above some heads I want to mention the two mechanisms of action:
1- post-ganglionic alpha 1 receptor is stimulated on aterioles
2- there seems to be repletion of adrenergic terminals with the neurochemical norepinephrine in both the peripheral nervous system and the central nervous system
The preliminary data is yet to be released but what was presented was very promising.
Midodrine which is another drug available to treat this condition has a greater effect on the blood pressure when lying down. Droxidopa has a greater effect when standing which is potentially more clinically important to patients.
The droxidopa seems to be well tolerated.
We await to hear about the 20-25% of patients who were excluded from the studies because the drug didn't seem to be effective enough in the dose titration part of the study,
We will keep you posted as more data becomes available.
Michael S. Okun, M.D.