title: [Quantitative determination and kinetics of dihydralazine in hypertension patients].
abstract: For the quantitative determination of dihydralazine (1) a derivative with acetylacetone in biological material was formed at pH = 4.9, extracted with n-hexane, and measured gaschromatographically with N-P-FID. Acid labile 1 was hydrolyzed with HCl (1 mol/l) for 24 h. The detection limit was 25 nmol/l plasma. Kinetic studies were performed in 16 patients with essential hypertension under steady-state conditions after the oral application of 50 mg 1. The acetylator phenotype was determined with sulfamethazine. Complete dihydralazine plasma level-time courses were found in only 5 cases. The concentrations were below the detection limit in 4 patients for the whole period. Only single values could be registered in the remaining patients. Maximal plasma levels of the free (58-314 nmol/l) and acid labile 1 (147-367 nmol/l) were reached 20-40 min after the application. The elimination half life was 23-47 min for the free 1, 55-92 min for the acid labile 1. Less than 0.5% of the applied drug were excreted into the 24 h urine in its free form, about 0.4% as acid labile derivatives. No correlation could be found between the acetylator phenotype of the patients and the kinetic behaviour of the drug. Preliminary studies concerning the biliary excretion of 1 after i. m. application in two patients with T-drain showed an accumulation of the free compound with bile/plasma ratios up to 7.4.
mesh_terms: D000107:Acetylation; D000328:Adult; D000368:Aged; D001646:Bile / Q000378:metabolism; D004078:Dihydralazine / Q000378:metabolism*; D005260:Female; D006801:Humans; D006830:Hydralazine / Q000031:analogs & derivatives*; D006973:Hypertension / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D010641:Phenotype
chemical_list: D006830:Hydralazine; D004078:Dihydralazine
vernacular_title: Quantitative Bestimmung und Kinetik von Dihydralazin bei Hypertoniepatienten.