[Hemodynamic study on a new antihypertensive drug (a pyridopyridazine) in the treatment of hypertensive crisis and resistent hypertension. First findings in man (author's transl)].

Hypertension presents many unsolved therapeutical problems. On this reason further examinations on new antihypertensive agents are needed. BQ 22-708 is a pyridopyridazine with peripheral vasodilating activities, which has been shown in animal experiments marked antihypertensive properties of dihydralazine-type. A hemodynamic study revealed now similar effects in man, as could be demonstrated in 5 patients with resistent hypertension and additional hypertensive crisis in two cases. At these patients BQ 22-708 in doses between 5 and 15 mg reduced the mean arterial pressure by 48 mm Hg, but at the same time increased heart rate. Peripheral resistance was significantly reduced by 30-60%. Cardiac output increased. Stroke volume remained unchanged in patients without heart failure, but in those with cardiac insufficiency increased. There was a slight but non-significant reduction in pulmonary artery pressure and capillary wedge pressure, wheras right atrial pressure remained unchanged. The onset of drug activity was noticed 10-20 minutes after application of a single dose BQ 22-708 and lasted for about 5-6 hours. Therefore BQ 22-708 may prove to be useful in the therapy of resistent hypertension.