Hemodynamic effects of a constant intravenous infusion of piroximone in patients with severe congestive heart failure.
The hemodynamic effects and serum levels of piroximone (MDL 19,205), a new inotropic agent with vasodilating properties, were measured in 10 patients with chronic severe congestive failure during a constant 48-h infusion. The initial five patients (group A) received piroximone at 10 micrograms/kg/min; however, because a sustained increase in heart rate greater than or equal to 25% from baseline developed in two patients and an episode of paroxysmal supraventricular tachycardia developed in another, the last 5 patients (group B) received an 8 micrograms/kg/min infusion. Because the steady-state hemodynamic alterations of group A prior to the onset of tachyarrhythmias were similar to those of group B, these results were combined. A significant increase in cardiac output from 3.65 +/- 0.31 (SE) to 5.20 +/- 0.49 L/min and decrease in pulmonary capillary wedge pressure (27 +/- 2 to 20 +/- 2 mm Hg), right atrial pressure (18 +/- 2 to 11 +/- 2 mm Hg), and systemic vascular resistance (1811 +/- 172 to 1293 +/- 80 dynes.s.cm-5) occurred (all p less than 0.05) without a significant change in mean arterial pressure. The peak plasma piroximone level was lower in the eight patients who did not develop a sustained increase in heart rate greater than or equal to 25% above baseline (2.1 +/- 0.5 micrograms/ml; range 1.6-2.9 micrograms/ml) than in the two who did (5.0 and 5.8 micrograms/ml). The latter two patients had the highest serum creatinine levels in the study population.(ABSTRACT TRUNCATED AT 250 WORDS)
Miller
W E
WE
Department of Medicine, University of Texas Health Science Center, San Antonio 78284-7872.
Kennedy
G T
GT
Ruberg
S J
SJ
O'Rourke
R A
RA
Crawford
M H
MH
D000368:Aged; D002316:Cardiotonic Agents / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D006333:Heart Failure / Q000188:drug therapy* / Q000503:physiopathology; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D007093:Imidazoles / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged
D002316:Cardiotonic Agents; D007093:Imidazoles; C039686:piroximone