Effects of midodrine hydrochloride on blood pressure and cerebral blood flow during orthostasis in persons with chronic tetraplegia.
OBJECTIVE
To determine the mean arterial pressure (MAP) and middle cerebral artery mean blood flow velocity (MFV) responses to 5 and 10mg midodrine during head-up tilt (HUT) in persons with tetraplegia.


METHODS
Prospective dose-response trial.


METHODS
James J. Peters Veterans Administration Medical Center.


METHODS
Persons (N=10) with chronic tetraplegia (duration of injury=23+/-11 y).


METHODS
A dose titration study was performed over 3 testing days: control (no drug), 5mg midodrine (5mg), or 10mg midodrine (10mg) during 30 minutes of baseline (predrug/no drug), 30 minutes of supine rest postdrug/no drug, 15 minutes of progressive HUT (5 minutes at 15 degrees , 25 degrees , 35 degrees ), and 45 minutes of 45 degrees HUT.


METHODS
MAP and MFV response to midodrine supine and during HUT.


RESULTS
Ten milligrams of midodrine significantly increased MAP while supine and during the HUT maneuver. Of note, the mean increase in MAP during HUT with 10mg was a result of a robust effect in 2 persons, with minimal change in the remaining 8 study subjects. The reduction in cerebral MFV during HUT was attenuated with 10mg.


CONCLUSIONS
These findings suggest that midodrine 10mg may be efficacious for treatment of hypotension and orthostatic hypotension in select persons with tetraplegia. Although midodrine is routinely prescribed to treat orthostatic hypotension, the results of our work suggests limited efficacy of this agent, but additional studies in a larger sample of subjects with spinal cord injury should be performed.
Wecht
Jill M
JM
James J. Peters Veterans Administration Medical Center, Bronx, NY, USA. JM.WECHT@VA.GOV
Rosado-Rivera
Dwindally
D
Handrakis
John P
JP
Radulovic
Miroslav
M
Bauman
William A
WA
D000328:Adult; D002560:Cerebrovascular Circulation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007022:Hypotension / Q000188:drug therapy* / Q000209:etiology; D007024:Hypotension, Orthostatic / Q000188:drug therapy / Q000209:etiology; D008297:Male; D008875:Middle Aged; D008879:Midodrine / Q000494:pharmacology / Q000627:therapeutic use*; D011782:Quadriplegia / Q000150:complications / Q000534:rehabilitation*; D013119:Spinal Cord Injuries / Q000150:complications / Q000534:rehabilitation*; D018667:Tilt-Table Test; D014662:Vasoconstrictor Agents / Q000494:pharmacology / Q000627:therapeutic use*
D014662:Vasoconstrictor Agents; D008879:Midodrine