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Contrasting actions of pressor agents in severe autonomic failureBACKGROUND: Orthostatic hypotension is the most disabling symptom of autonomic failure. The choice of a pressor agent is largely empiric, and it would be of great value to define predictors of a response. PATIENTS AND METHODS: In 35 patients with severe orthostatic hypotension due to multiple system atrophy or pure autonomic failure, we determined the effect on seated systolic blood pressure (SBP) of placebo, phenylpropanolamine (12.5 mg and 25 mg), yohimbine (5.4 mg), indomethacin (50 mg), ibuprofen (600 mg), caffeine (250 mg), and methylphenidate (5 mg). In a subgroup of patients, we compared the pressor effect of midodrine (5 mg) with the effect of phenylpropanolamine (12.5 mg). RESULTS: There were no significant differences in the pressor responses between patients with multiple system atrophy or pure autonomic failure. When compared with placebo, the pressor response was significant for phenylpropanolamine, yohimbine, and indomethacin. In a subgroup of patients, we confirmed that this pressor effect of phenylpropanolamine, yohimbine, and indomethacin corresponded to a significant increase in standing SBP. The pressor responses to ibuprofen, caffeine, and methylphenidate were not significantly different from placebo. Phenylpropanolamine and midodrine elicited similar pressor responses. There were no significant associations between drug response and autonomic function testing, postprandial hypotension, or plasma catecholamine levels. CONCLUSIONS: We conclude that significant increases in systolic blood pressure can be obtained in patients with orthostatic hypotension due to primary autonomic failure with phenylpropanolamine in low doses or yohimbine or indomethacin in moderate doses. The response to a pressor agent cannot be predicted by autonomic function testing or plasma catecholamines. Therefore, empiric testing with a sequence of medications, based on the risk of side effects in the individual patient and the probability of a response, is a useful approach.
Document ID
20040172577
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Jordan, J.
(Clinical Research Center, Franz Volhard Clinic Berlin, Germany)
Shannon, J. R.
Biaggioni, I.
Norman, R.
Black, B. K.
Robertson, D.
Date Acquired
August 22, 2013
Publication Date
August 1, 1998
Publication Information
Publication: The American journal of medicine
Volume: 105
Issue: 2
ISSN: 0002-9343
Subject Category
Aerospace Medicine
Funding Number(s)
CONTRACT_GRANT: HL44589
CONTRACT_GRANT: RR00095
Distribution Limits
Public
Copyright
Other
Keywords
Clinical Trial
Non-NASA Center
NASA Discipline Regulatory Physiology
Controlled Clinical Trial

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