Efficacy of Midodrine vs Placebo in Neurogenic Orthostatic Hypotension
A Randomized, Double-blind Multicenter Study
- Phillip A. Low, MD;
- Janice L. Gilden, MD;
- Roy Freeman, MD;
- Ke-Ning Sheng, PhD;
- Mary Ann McElligott, PhD
- for the Midodrine Study Group
- From the Department of Neurology, Mayo Clinic, Rochester, Minn (Dr Low); Finch University of Health Sciences, The Chicago Medical School, North Chicago, III (Dr Gilden); Beth Israel-Deaconess Medical Center, Boston, Mass (Dr Freeman); and Roberts Pharmaceutical Corp, Eatontown, NJ (Drs Sheng and McElligott).
Abstract
Objective. —To evaluate the efficacy of a 10-mg dose of midodrine 3 times per day in improving blood pressure (BP) and ameliorating symptoms of orthostatic hypotension in patients with neurogenic orthostatic hypotension. Midodrine hydrochloride, an α=agonist, could improve orthostatic BP by increasing vasomotor and venomotor tone.
Design/Methods. —A total of 171 patients with orthostatic hypotension participated in a multicenter, randomized, placebo-controlled study. They were randomized to a 10-mg dose of midodrine or placebo 3 times per day in a 6-week study, comprising single-blind run-in (at week 1) and washout at weeks 5 and 6, with an intervening double-blind period (weeks 2 to 4).
Setting. —Twenty-five centers, with most patients evaluated in referral centers.
Main Outcome Measures. —The primary end points were improvement in standing systolic BP, symptoms of lightheadedness, and a global symptom relief score (by the investigator and patient separately).
Results. —Nine patients were not evaluable because of noncompliance or taking concomitant vasoactive medications (3 in the midodrine group, 6 in the placebo group). In the evaluable patients, midodrine resulted in improvements in standing systolic BP at all time points (P<.001 at visits 2,3,4, and 5), in reported symptoms by the end of the second week of treatment (P=.001), and in the global symptom relief score rated by both the patient (P=.03) and the investigator (P<.001). There was no effect by center, severity of orthostatic hypotension, use of fludrocortisone or compression garments, or diagnosis. The main adverse effects were those of pilomotor reactions, urinary retention, and supine hypertension.
Conclusions. —Midodrine is efficacious and safe in the treatment of neurogenic orthostatic hypotension.
Footnotes
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A complete list of the Midodrine Study Group appears at the end of this article.
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Nothing in this publication implies that Mayo Foundation endorses the products of Roberts Pharmaceutical Corp.
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Reprints: Phillip A. Low, MD, Autonomic Reflex Laboratory, Department of Neurology, Mayo Clinic, 811 Guggenheim Bldg, Rochester, MN 55905 (e-mail: low.phillip@mayo.edu).
