The purpose of this study was to compare two treatments for
orthostatic hypotension,
midodrine (an
alpha adrenergic agonist), and
octreotide (an SRIH analogue) to each other and to combination
therapy. Sixteen patients participated. Our hypothesis was that the 2 drugs together would be more effective than either
drug alone. The effect of the drugs on the hemodynamic response to food ingestion was evaluated while patients were sitting.
Midodrine (5 mg orally, 30 min before breakfast) increased mean blood pressure slightly (5-10 mm Hg, over 30 min) before the patients started eating, but it only partially reversed the hypotensive effect of food ingestion. The nadir in postprandial blood pressure after
midodrine was 69 +/- 4 mm Hg, not different from placebo (63 +/- 5). Nevertheless,
midodrine accentuated the response to sc
octreotide (0.5 microgram/kg). Fifteen minutes after
octreotide administration to
midodrine-pretreated patients, the average mean blood pressure was 115 +/- 9 mm Hg, higher (P = .0095) than after
octreotide given alone (102 +/- 7).
Drug effects on
orthostatic hypotension were assessed by measuring standing time (minutes before symptoms of
hypotension or definite
hypotension). In the absence of treatment, standing time was 3.5 +/- 7 min; 1 h after 10 mg
midodrine, 8.4 +/- 2.7 min (
P = .11); after 1.0 microgram/kg
octreotide, 13.2 +/- 3.9 min (P = .0034 vs. no treatment); and after both drugs, 21.2 +/- 5.5 min (P = .0002 vs. no treatment, P = .036 vs.
octreotide only). The combination of
midodrine and
octreotide is more potent than either
drug alone.