n-(4-(4-methyl-6-oxo-1-4-5-6-tetrahydropyridazin-3-yl)phenyl)acetamide and Heart-Failure

Levosimendan is indicated for acute heart failure. The formation of levosimendan's active metabolite OR-1896 is dependent on the acetylator status. We evaluated whether acetylator status affects the hemodynamic responses after levosimendan infusion.. Forty-one NYHA III to IV heart failure patients were divided into rapid and slow acetylators by population kinetic modeling. Invasive hemodynamics and plasma concentrations of levosimendan and its metabolites were followed serially.. Fifty-six percent of the patients were rapid and 44% slow acetylators. Levosimendan induced increases in heart rate and cardiac output, and decreases in pulmonary capillary wedge pressure (PCWP) and blood pressure, which were sustained at 24 hours after stopping the infusion. At this time, levosimendan levels were undetectable, and OR-1896 levels were about two-fold higher in rapid acetylators. However, hemodynamic effects were similar; mean(SEM) change from baseline in cardiac output was +2.0(0.3) vs. +1.6(0.3) l/min (p = 0.309), and in PCWP -8(2) vs. -7(1) mmHg (p = 0.536), in rapid and slow acetylators, respectively.. The sustained hemodynamic effects of levosimendan are similar irrespective of acetylator status.

Topics: Acetamides; Acetylation; Double-Blind Method; Female; Follow-Up Studies; Heart Failure; Hemodynamics; Humans; Hydrazones; Male; Middle Aged; Pyridazines; Severity of Illness Index; Simendan; Treatment Outcome; Vasodilator Agents

Levosimendan is a calcium-sensitizing drug for the treatment of heart failure. The aim of this exploratory study was to assess the hemodynamic and pharmacokinetic interactions between digoxin and oral levosimendan as well as the proarrhythmic potential of this combination in patients with chronic heart failure.. Male or female patients (n = 24) with chronic heart failure of NYHA Classes II-III.. A randomized, placebo-controlled, double-blind, parallel-group trial. After a 1-week digoxin-free washout period, the patients were randomized to receive either digoxin and levosimendan (digoxin + levosimendan), or digoxin and placebo (digoxin) orally for 14 +/- 2 days. The levosimendan dose was 1 mg 3 times daily, and the digoxin dose was 0.125-0.25 mg once daily. Systolic time intervals, electrocardiography (ECG), magneto-cardiography (MCG) and 24-h ambulatory ECG were performed at baseline and at the end of each treatment period. Pharmacokinetic variables of levosimendan and digoxin were calculated in both treatment periods. Steady-state concentrations of the active metabolites OR-1855 and OR-1896 were determined at baseline at Visit 2.. There tended to be a greater shortening of QS2i (suggesting trend to positive inotropy) in the digoxin + levosimendan group (-14ms) compared with the digoxin group (-5ms), although the difference was not statistically significant (p=0.359). However, the change from baseline in QS2i after digoxin + levosimendan was of statistically borderline significance (p=0.05). The change from baseline in the digoxin group was not statistically significant. ECG and MCG repolarization measures and occurrence of nonsustained ventricular tachycardia showed no substantial differences. After 2 weeks of digoxin + levosimendan treatment, mean area under the curve (AUC) of levosimendan increased approximately by 49% (p<0.01). The maximum plasma concentration (Cmax) of levosimendan increased from 17 to 23 ng/ml. The mean concentrations of the metabolites OR-1855 and OR-1896 in plasma were 4.3 and 8.3 ng/ml, respectively.. The addition of oral levosimendan to digoxin therapy produced only a modest statistically nonsignificant additive inotropic effect. In contrast to the earlier data with intravenous levosimendan, the results indicate a pharmacokinetic interaction between levosimendan and digoxin. Data obtained from repolarization analyses and ambulatory ECG did not indicate any possible proarrhythmic effects of the combination.

Topics: Acetamides; Administration, Oral; Aged; Area Under Curve; Cardiotonic Agents; Chronic Disease; Digoxin; Dose-Response Relationship, Drug; Double-Blind Method; Electrocardiography; Female; Heart Failure; Hemodynamics; Humans; Hydrazones; Magnetocardiography; Male; Middle Aged; Pyridazines; Simendan

The purpose of the study was to characterize the pharmacokinetics of levosimendan and its metabolites OR-1855 and OR-1896 in patients with congestive heart failure.. Levosimendan was administered as a continuous intravenous infusion for 7 days. Twelve subjects received the drug at an infusion rate of 0.05 micro g kg(-1) min(-1) and 12 at a rate 0.1 micro g kg(-1) min(-1).. Steady state concentrations of levosimendan were achieved within 4 h. Peak concentrations of the metabolites occurred after termination of the infusion. The mean (+/- SD) half-life of the active metabolite OR-1896 was 81 +/- 37 h after the lower dose and 81 +/- 28 h after the higher dose (P = 0.992, 95% confidence interval on the difference -27.5, 27.7).. The metabolites of levosimendan, OR-1855 and OR-1896, were formed and eliminated slowly, their peak concentrations occurring after termination of the 7-day infusion of the drug.

Topics: Acetamides; Cardiotonic Agents; Female; Heart Failure; Humans; Hydrazones; Infusions, Intravenous; Male; Protein Binding; Pyridazines; Simendan

Levosimendan is a novel, short half-life calcium sensitizer used as pharmacological inotropic support in acute decompensated heart failure. After oral administration, levosimendan is metabolized to OR-1855, which, in rats, is further metabolized into OR-1896. OR-1896 is a long-lasting metabolite of levosimendan sharing the pharmacological properties of the parent compound.. Effects of oral OR-1896 treatment on post-infarct heart failure and cardiac remodelling were assessed in diabetic Goto-Kakizaki (GK) rats, an animal model of type II diabetes. Myocardial infarction (MI) was produced to GK rats by coronary ligation. Twenty-four hours after MI or sham operation, the rats were randomized into four groups: (i) MI; (ii) MI + OR-1896 treatment; (iii) sham; and (iv) sham + OR-1896. Cardiac function and markers of cardiac remodelling were assessed 1, 4 and 12 weeks after MI.. OR-1896 increased ejection fraction and fractional shortening in GK rats with MI. OR-1896 ameliorated post-infarct cardiac hypertrophy, and prevented the MI-induced increase in cardiac mRNA for atrial natriuretic peptide, monocyte chemoattractant protein-1 and connective tissue growth factor, markers of pressure/volume overload, inflammation and fibrosis respectively. OR-1896 also suppressed mRNA for senescence-associated p16(INK4A) and p19(ARF). The beneficial effects of OR-1896 were more prominent at week 12 than at week 4. OR-1896 did not influence systolic blood pressure, blood glucose level, myocardial infarct size or cardiovascular mortality.. Oral treatment with calcium sensitizer OR-1896 protects against post-infarct heart failure and cardiac remodelling in experimental model of type II diabetes.

Topics: Acetamides; Animals; Biomarkers; Cardiac Volume; Cellular Senescence; Diabetes Mellitus, Type 2; Fibrosis; Heart Failure; Inflammation; Mitochondria, Heart; Myocardial Infarction; Myocytes, Cardiac; Pyridazines; Random Allocation; Rats; Tetrazoles; Time Factors; Valine; Valsartan; Vasodilator Agents; Ventricular Pressure

During heart failure, alterations occur in contractile protein expression and phosphorylation, which may influence the effects of Ca2+ -sensitizers. To quantify the magnitude of these effects, isometric force was studied in mechanically isolated Triton-skinned myocytes from end-stage failing and non-failing donor hearts under control conditions (pH 7.2; no added inorganic phosphate (Pi)) and under mimicked ischemic conditions (pH 6.5; 10 mM Pi). Two different Ca2+ -sensitizers were used: EMD 53998 (10 microM), which exerts its influence through the actin-myosin interaction, and OR-1896 (10 microM) (the active metabolite of levosimendan), which affects the Ca2+ -sensory function of the thin filaments. The maximal force (Po) measured at saturating Ca2+ concentration and the resting force (Prest) determined in the virtual absence of Ca2+ (pCa 9) did not differ between the failing and non-failing myocytes, but the Ca2+ concentration required to induce the half-maximal force under control conditions was significantly lower in the failing than in the non-failing myocytes (DeltapCa50=0.15). This difference in Ca2+ -sensitivity, however, was abolished during mimicked ischemia. EMD 53998 increased Po and Prest by approximately 15% of Po and greatly enhanced the Ca2+ -sensitivity (DeltapCa50 > 0.25) of force production. OR-1896 did not affect Po and Prest, and provoked a small, but significant Ca2+ -sensitization (DeltapCa50 approximately 0.1). All of these effects were comparable in the donor and failing myocytes, but, in contrast with OR-1896, EMD 53998 considerably diminished the difference in the Ca2+ -sensitivities between the failing and non-failing myocytes. The action of Ca2+ -sensitizers under mimicked ischemic conditions was impaired to a similar degree in the donor and the failing myocytes. Our results indicate that the Ca2+ -activation of the myofibrillar system is altered in end-stage human heart failure. This modulates the effects of Ca2+ -sensitizers both under control and under mimicked ischemic conditions.

Topics: Acetamides; Adult; Aged; Calcium; Cell Membrane Permeability; Female; Heart Failure; Humans; In Vitro Techniques; Male; Middle Aged; Myocardium; Myocytes, Cardiac; Pyridazines; Quinolines; Thiadiazines; Tissue Donors