Abstract
The hemodynamic and neurohumoral effects of cummulative intravenous doses of piroximone (MDL 19205), a noncatecholamine, nonglycoside, imidazole derivative with positive inotropic and vasodilating properties, were studied in eight patients with severe congestive heart failure. A dose of 1.25 mg/kg in seven patients and 1.75 mg/kg in one patient increased cardiac index by 75% from 1.96 to 3.41 liters/min per m2 and decreased systemic vascular resistance (−41%), right atrial (−66%) and pulmonary wedge pressure (−35%) (all p < 0.005). Mean arterial pressure was slightly reduced from 78 to 71 mm Hg (p < 0.05) and forearm blood flow increased by 42%. Plasma norepinephrine decreased from 830 to 542 pg/ml (p < 0.05) and plasma renin activity tended to increase. In four patients, dobutamine (15 μg/kg per min) produced a comparable increase in cardiac index (+100%), but less decrease in pulmonary wedge pressure (−21 versus −41%, p < 0.05 versus piroximone) and, unlike piroximone, significantly increased heart rate (+22%, p < 0.05 versus piroximone) and heart rate-blood pressure product (+30%, p < 0.01 versus piroximone). In four other patients, a single intravenous dose of piroximone (1 mg/kg) resulted in a 35% increase in the first derivative of left ventricular pressure (dP/dt) from 796 to 1,068 mm Hg/s (p < 0.01). Thus, piroximone is a potent inotropic agent with an acute hemodynamic profile that may be more favorable than that of dobutamine. Because the drug is orally absorbed, clinical trials of chronic efficacy are indicated.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 364-371 |
| Number of pages | 8 |
| Journal | Journal of the American College of Cardiology |
| Volume | 4 |
| Issue number | 2 |
| DOIs | |
| State | Published - 1984 |
Bibliographical note
Funding Information:From the of Minnesota Medical School, supported in part by Grant HL 22977 from the National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland. Manuscript received December 13, 1983; revised manuscript received February 6, 1984, accepted February 28, 1984. Address for reprints: T. Barry Levine, MD, University of Minnesota 79, Mayo Memorial Building, Minneapolis, Minnesota
