TREATMENT OF ORTHOSTATIC HYPOTENSION WITH ERYTHROPOIETIN

Background and Methods. Patients with orthostatic hypotension caused b y autonomic neuropathy frequently have a decreased red-cell mass. This would be expected to compromise their effective circulating blood vol ume and aggravate the orthostatic hypotension. We studied the effect o f increasing the red-cell mass with erythropoietin, given subcutaneous ly in a dose of 50 U per kilogram of body weight three times a week fo r 6 to 10 weeks to eight patients with orthostatic hypotension - four men, one teenage boy, and three women (age range, 17 to 68 years). Fou r patients had type I diabetes mellitus and autonomic neuropathy, thre e patients had pure autonomic failure, and one patient had sympathoton ic orthostatic hypotension. Seven patients received fludrocortisone (0 .1 or 0.2 mg per day) before, during, and after the trial of erythropo ietin. The red-cell volume, plasma volume, and hemodynamic response to orthostatic stress were measured before and after therapy. Results. E rythropoietin increased the mean (+/-SD) hematocrit from 0.34+/-0.04 t o 0.45+/-0.04 (P<0.005) and increased the red-cell volume from 16.8+/- 3.9 to 25.3+/-3.1 ml per kilogram (P<0.005), but had no effect on plas ma volume. The systolic blood pressure increased from 81+/-11 to 100+/ -24 mm Hg (P<0.01) and the diastolic blood pressure increased from 46/-10 to 63+/-18 mm Hg (P<0.01) while the patients were standing. The a verage systolic and diastolic blood pressure while the patients were s upine did not increase significantly, although hypertension in the sup ine position developed in three patients. Orthostatic dizziness improv ed during treatment in six of the eight patients. Conclusions. In pati ents with orthostatic hypotension, increasing the red-cell volume with erythropoietin elevates blood pressure while standing. Possible long- term adverse effects are not known.