title: Antihypertensive effect of diazoxide given intravenously in small repeated doses.
abstract: Seven patients with acutely elevated diastolic blood pressure (DBP greater than or equal to 135 mmHg) were treated with repeated injections of diazoxide 1 mg/kg body weight i.v. at 10-min intervals. If the DBP was not reduced to 110 mmHg or less after 5 injections, a dose of 5 mg/kg was given. Serum diazoxide (total and unbound) was determined by high pressure liquid chromatography. In all the patients it was possible to reduce the blood pressure to a satisfactory level (i.e. DBP less than 110 mmHg). The individual plasma diazoxide concentrations necessary to achieve the desired response ranged from 20 to 85 micrograms/ml. A significant correlation was found between the initial venous concentration and the initial reduction in blood pressure (p less than 0.02). A high initial concentration in venous blood was associated with high protein binding ("transport function", p less than 0.05), and so were the elimination half-lives, which ranged from 14.7 to 61.3 h ("depot function", p less than 0.05). It is concluded that the previously recommended therapy of injection of 5 mg/kg as a bolus should be given only to patients who do not respond to small repeated doses.
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D003981:Diazoxide / Q000008:administration & dosage* / Q000378:metabolism / Q000494:pharmacology; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D011485:Protein Binding
chemical_list: D003981:Diazoxide