Orthostatic effects of midodrine versus L-NAME on cerebral blood flow and the renin-angiotensin-aldosterone system in tetraplegia.
Arch Phys Med Rehabil
; 92(11): 1789-95, 2011 Nov.
Article
in En
| MEDLINE
| ID: mdl-21762873
ABSTRACT
OBJECTIVE:
To compare responses to head-up tilt (HUT) in individuals with chronic tetraplegia after midodrine hydrochloride (10 mg) versus nitro-L-arginine methyl ester (L-NAME, 1 mg/kg) administration.DESIGN:
Prospective comparative drug trial.SETTING:
Veterans Affairs medical center.PARTICIPANTS:
Participants (N=7) were studied during 3 laboratory visits no drug, midodrine (administered orally 30 min before HUT), and L-NAME (infused over a 60-min period).INTERVENTIONS:
Anti-hypotensive agents, midodrine, and L-NAME. MAIN OUTCOMEMEASURES:
Mean arterial pressure (MAP), cerebral blood flow (CBF), and markers of the renin-angiotensin-aldosterone system (RAAS, plasma renin and serum aldosterone) were measured in the supine position at baseline (BL) and during a 45° HUT maneuver. Data were compared between BL and the average of 3 assessments collected during HUT.RESULTS:
Orthostatic MAP and CBF were increased with the midodrine and L-NAME groups compared with the no drug trial and the relationship between the change in MAP and CBF was significant (r=0.770; P<0.001). Both L-NAME and midodrine appeared to suppress the post-HUT RAAS response compared with no drug.CONCLUSIONS:
Increasing orthostatic blood pressure with L-NAME or midodrine appears to increase CBF and suppress the RAAS during HUT in persons with tetraplegia, although more data are needed to confirm these preliminary findings.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Renin-Angiotensin System
/
Vasoconstrictor Agents
/
Cerebrovascular Circulation
/
NG-Nitroarginine Methyl Ester
/
Dizziness
/
Midodrine
Type of study:
Observational_studies
Limits:
Adult
/
Female
/
Humans
/
Male
/
Middle aged
Country/Region as subject:
America do norte
Language:
En
Journal:
Arch Phys Med Rehabil
Year:
2011
Document type:
Article
Affiliation country:
United States