Prenalterol in the treatment of orthostatic hypotension in Shy-Drager syndrome.
The effects of prenalterol, a selective beta 1-adrenoreceptor agonist, were studied in a patient with the Shy-Drager syndrome, presenting with incapacitating orthostatic hypotension. The main haemodynamic defect was an impressive postural fall in stroke volume and cardiac output pointing to denervation of the capacitance vessels. Prenalterol 4 X 30 mg orally produced a marked increase in supine and standing blood pressure, along with substantial symptomatic improvement. Notable positive chronotropic and inotropic effects were observed. Association of fludrocortisone 0.5 mg/day resulted in further haemodynamic and symptomatic improvement, presumably due to plasma volume expansion. Haemodynamically, prenalterol and fludrocortisone resulted in a substantial increase in standing cardiac output, primarily due to the chronotropic effects of prenalterol. In addition to the haemodynamic effects, prenalterol stimulated the renin-aldosterone system and restored the normal diurnal pattern of water and sodium excretion, the latter may have contributed to the improvement of orthostatic tolerance. Prenalterol could be a valuable adjunct to the existing treatment schedules of neurogenic orthostatic hypotension.
D000318:Adrenergic beta-Agonists / Q000627:therapeutic use*; D001342:Autonomic Nervous System Diseases / Q000150:complications*; D004359:Drug Therapy, Combination; D005438:Fludrocortisone / Q000008:administration & dosage / Q000627:therapeutic use; D006321:Heart / Q000503:physiopathology; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007024:Hypotension, Orthostatic / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011217:Practolol / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use; D011294:Prenalterol; D012791:Shy-Drager Syndrome / Q000150:complications*
D000318:Adrenergic beta-Agonists; D011294:Prenalterol; D011217:Practolol; D005438:Fludrocortisone