Pharmacodynamics and Pharmacokinetics of Oral Levosimendan and Its Metabolites in Patients With Severe Congestive Heart Failure: A Dosing Interval Study

Understanding the Clinical Use of Levosimendan and Perspectives on its Future in Oncology

Drug repurposing, also known as repositioning or reprofiling, has emerged as a promising strategy to accelerate drug discovery and development. This approach involves identifying new medical indications for existing approved drugs, harnessing the extensive knowledge of their bioavailability, pharmacokinetics, safety and efficacy. Levosimendan, a calcium sensitizer initially approved for heart failure, has been repurposed for oncology due to its multifaceted pharmacodynamics, including phosphodiesterase 3 inhibition, nitric oxide production and reduction of reactive oxygen species. Studies have demonstrated that levosimendan inhibits cancer cell migration and sensitizes hypoxic cells to radiation. Moreover, it exerts organ-protective effects by activating mitochondrial potassium channels. Combining levosimendan with traditional anticancer agents such as 5-fluorouracil (5-FU) has shown a synergistic effect in bladder cancer cells, highlighting its potential as a novel therapeutic approach. This drug repurposing strategy offers a cost-effective and time-efficient solution for developing new treatments, ultimately contributing to the advancement of cancer therapeutics and improved outcomes for patients. Further investigations and clinical trials are warranted to validate the effectiveness of levosimendan in oncology and explore its potential benefits in a clinical setting.

Oral Levosimendan Increases Cerebral Blood Flow Velocities in Patients with a History of Stroke or Transient Ischemic Attack: A Pilot Safety Study

Background

Intravenous levosimendan is indicated for acute heart failure. The compound has shown promising beneficial effects in ischemic stroke models.

Objective

We evaluated the efficacy and safety of oral levosimendan in patients with a history of cerebral ischemia.

Methods

In a randomized, double-blind, placebo-controlled, parallel-group study, 16 patients with a history of ischemic stroke/transient ischemic attack received oral levosimendan in 5 escalating doses from 0.125 to 2.0 mg daily for 18-day intervals of each dose; 5 patients received placebo. Twenty-four-hour ambulatory ECG and cerebral blood flow velocities using transcranial Doppler ultrasound were recorded at baseline and at the end of each dosing period. Vasomotor reactivity was assessed via the breath holding index. In addition, plasma levels of N-terminal-pro-B-type natriuretic peptide (NT-pro-BNP) and the metabolites of levosimendan were determined.

Results

Levosimendan induced an increase in cerebral blood flow velocities and a decrease in NT-pro-BNP compared with placebo. There was no significant effect on breath holding index. Doses ≥0.5 mg increased heart rate by 5 to 9 beats/min. The dose level of 2.0 mg exceeded the preset safety margin of ventricular extrasystoles per hour (ie, upper 90% CI of the ratio of levosimendan to placebo above 2) with an estimate of 3.10 (90% CI, 0.95–10.07).

Conclusions

Oral levosimendan increases cerebral blood flow velocities and diminishes NT-pro-BNP levels in patients with earlier ischemic cerebrovascular event. Daily doses up to 1.0 mg were well tolerated, whereas the 2.0 mg dose level induced an increase in ventricular extrasystoles. ClinicalTrials.gov identifier: NCT00698763.

Intermittent levosimendan improves mid-term survival in chronic heart failure patients: meta-analysis of randomised trials

AIMS

Standard inotropic treatment is often necessary in end-stage heart failure but may be harmful. We performed a meta-analysis of randomized controlled trials to investigate the effect of repeated administration of levosimendan on survival in patients with chronic heart failure.

METHODS AND RESULTS

Four investigators independently searched in CENTRAL, Google Scholar MEDLINE/PubMed, Scopus and the Cochrane Central Register of clinical trials to identify any randomized study ever performed with intermittent levosimendan intravenous administration in adult patients with chronic heart failure with no restrictions on dose or time of administration. Data from a total of 326 patients from six randomized controlled studies using intermittent levosimendan in a cardiological setting were included in the analysis. Levosimendan was associated with a significant reduction in mortality at the longest follow-up available [32 of 168 (19 %) in the levosimendan group 46 of 133 (35 %) in the control arm, RR = 0.55 (95 % CI 0.37-0.84), p for effect = 0 0.005, p for heterogeneity = 0.3, I (2) = 23.4 %, NNT = 6 with 5 studies included]. Brain natriuretic peptide values, ejection fraction and number of patients with New York Heart Association ≥ III status were similar in survivors of both groups.

CONCLUSIONS

A large randomized trial is necessary to confirm the promising beneficial effects of intermittent levosimendan administration on the mid-term survival of patients with chronic heart failure.

Pharmacology of levosimendan: inotropic, vasodilatory and cardioprotective effects

WHAT IS KNOWN AND OBJECTIVE

Positive inotropic agents are frequently used in acute decompensated heart failure (ADHF) due to left ventricular systolic dysfunction. These agents are known to improve cardiac performance and peripheral perfusion in the short-term treatment. However, several preclinical and clinical studies emphasized detrimental effects of these drugs on myocardial oxygen demand and on sympathetic tone entailing arrhythmogenesis. Levosimendan is an inotropic agent with an original mechanism of action. This review focuses on major data available for levosimendan.

METHODS

A literature search was conducted in the PubMed database by including studies published in English using combinations of the following key words, levosimendan, inotropic drugs and acute heart failure. Furthermore, bibliographies of selected references were also evaluated for relevant articles. The collection for this review was limited to the most recently available human and animal data.

RESULTS AND DISCUSSION

Levosimendan's vasodilatory and cardioprotective effects are mediated by calcium sensitization of contractile proteins and opening of adenosine triphosphate (ATP)-dependent K+ channels in vascular smooth muscle cells and on mitochondrial ATP-sensitive potassium [mito.K(ATP)] channels. This inotropic agent has mild PDE inhibitory action. Unlike other inotropic agents, levosimendan improves cardiac performance without activating the sympathetic nervous system. Moreover, there are evidences that levosimendan has additional anti-inflammatory and anti-apoptotic properties that prevent cardiac toxicity and contributes to positive hemodynamic response of the drug. Four randomized trials evaluated the effects of levosimendan on mortality in patients with acute decompensated chronic heart failure; nevertheless, a clear benefit has not been demonstrated so far. Although levosimendan is indicated for the treatment of ADHF (class of recommendation IIa, level of evidence B), it is has not been approved in all countries.

WHAT IS NEW AND CONCLUSION

This review summarizes the characteristics and the current knowledge of the literature on levosimendan and its active metabolite OR-1896.

Efficiency and safety of prolonged levosimendan infusion in patients with acute heart failure

Background. Levosimendan is an inotropic drug with unique pharmacological advantages in patients with acute heart failure. Scope of this study is to determine whether longer infusion patterns without the hypotension-inducing loading dose could justify an effective and safe alternative approach. Methods. 70 patients admitted to the emergencies with decompensated chronic heart failure received intravenously levosimendan without a loading dose up to 72 hours. Clinical parameters, BNP (Brain Natriuretic Peptide) and signal-averaged-ECG data (SAECG) were recorded up to 72 hours. Results. The 48-hour group demonstrated a statistically significant BNP decrease (P < .001) after 48 hours, which also maintained after 72 hours. The 72-hour group demonstrated a bordeline decrease of BNP after 48 hours (P = .039), necessitating an additional 24-hour infusion to achieve significant reduction after 72 hours (P < .004). SAECG data demonstrated a statistically significant decrease after 72 hours (P < .04). Apart from two deaths due to advanced heart failure, no major complications were observed. Conclusion. Prolonged infusion of levosimendan without a loading dose is associated with an acceptable clinical and neurohumoral response.

Levosimendan and Calcium Sensitization of the Contractile Proteins in Cardiac Muscle: Impact on Heart Failure

Levosimendan increases the sensitivity of the cardiac fibrils to calcium, favorably affects hemodynamics in patients with heart failure. It is a positive inotrope and a peripheral vasodilator. The elimination half-life of the compound is about 1 hour. The drug decreases pulmonary capillary wedge pressure, increases cardiac output with the improvement in left ventricular ejection fraction leading to symptomatic improvement which includes decreased dyspnea and fatigue. Levosimendan can be used safely with diuretics, nitrates, beta-blockers, digoxin, and angiotensin-converting enzyme inhibitors. The most common adverse effects of levosimendan are headache and hypotension. Prolongation of the QTc interval does not appear to increase the incidence of arrhythmias, including ventricular tachycardia, ventricular fibrillation, and torsades de pointes. Levosimendan is a novel agent in the treatment of decompensated heart failure, representing a newer class of medications aimed at increasing calcium sensitivity. Its properties holds promise for the treatment of heart failure but further large-scale studies will be needed to determine its precise efficacy, safety, as well as the compound's long-term impact on mortality.

Inoprotection: the perioperative role of levosimendan

Levosimendan is emerging as a novel cardioprotective inotrope. Levosimendan augments myocardial contractility by sensitising contractile myofilaments to calcium without increasing myosin adenosine triphosphatase activity or oxygen consumption. Levosimendan activates cellular adenosine triphosphate-dependent potassium channels, a mechanism which is postulated to protect cells from ischaemia in a manner similar to ischaemic preconditioning. Levosimendan may therefore protect the ischaemic myocardium during ischaemia-reperfusion as well as improve the contractile function of the heart. Adenosine triphosphate-dependent potassium channel activation by levosimendan may also be protective in other tissues, such as coronary vascular endothelium, kidney and brain. Clinical trials in patients with decompensated heart failure and myocardial ischaemia show levosimendan to improve haemodynamic performance and potentially improve survival. This paper reviews the known pharmacology of levosimendan, the clinical experience with the drug to date and the potential use of levosimendan as a cardioprotective agent during surgery.

[Role of Levosimendan in intensive care treatment of myocardial insufficiency]

Levosimendan is a calcium sensitizer that is currently in the focus of intensive care medicine because it may be superior to standard inotropic agents in the treatment of acute myocardial insufficiency. The effects of levosimendan mainly depend on three predominant mechanisms: 1) positive inotropic effect by increasing the sensitivity of cardiac myofilaments to calcium ions, 2) vasodilatory effect by stimulation of adenosine triphosphate-sensitive potassium channels and 3) inhibition of phosphodiesterase-III. In a large number of experimental and clinical studies further possible indications for levosimendan have been described, e.g. cardioprotection during ischemia, cardiogenic shock, septic myocardial insufficiency and pulmonary hypertension. This review article critically summarizes the current scientific and clinical knowledge about levosimendan, its pharmacologic characteristics, mechanisms of action as well as indications and potential risks.

Clinical pharmacology of levosimendan

Levosimendan has been developed for the treatment of decompensated heart failure and is used intravenously when patients with heart failure require immediate initiation of drug therapy. It increases cardiac contractility and induces vasodilatation. The pharmacokinetics of levosimendan are linear at the therapeutic dose range of 0.05-0.2 microg/kg/minute. The short half-life (about 1 hour) of the parent drug, levosimendan, enables fast onset of drug action, although the effects are long-lasting due to the active metabolite OR-1896, which has an elimination half-life of 70-80 hours in patients with heart failure (New York Heart Association functional class III-IV). Although levosimendan is administered intravenously, it is excreted into the small intestine and reduced by intestinal bacteria to an amino phenolpyridazinone metabolite (OR-1855). This metabolite is further metabolised by acetylation to N-acetylated conjugate (OR-1896). The circulating metabolites OR-1855 and OR-1896 are formed slowly, and their maximum concentrations are seen on average 2 days after stopping a 24-hour infusion. The haemodynamic effects after levosimendan seem to be similar between fast and slow acetylators despite the fact that the enzyme N-acetyltransferase-2, which is responsible for the metabolism of OR-1855 to OR-1896, is polymorphically distributed in the population. Levosimendan reduces peripheral vascular resistance and has direct contractility-enhancing effects on the failing left ventricle. It also improves indices of diastolic function and seems to improve the function of stunned myocardium. Despite an improvement in ventricular function, levosimendan does not increase myocardial oxygen uptake significantly. An increase in coronary blood flow and a reduction in coronary vascular resistance have been observed. Levosimendan reduces plasma brain natriuretic peptide (BNP) and N-terminal pro-BNP (NT-proBNP) levels substantially, and a decrease in plasma endothelin-1 has been observed. Levosimendan also exerts beneficial effects on proinflammatory cytokines and apoptosis mediators. The effects of a 24-hour levosimendan infusion on filling pressure, ventricular function and BNP, as well as NT-proBNP, last for at least 7 days.

Ca2+-sensitisers--a promising option to treat heart failure?

Because the number of transplants is still fewer than the number of patients waiting for a donor organ, new concepts of therapy are needed that allow patients to bridge the time gap until heart transplantation or even to improve symptoms while on treatment. Ca(2+)-sensitisers are agents that directly influence myofilaments and/or the cross-bridge-cycle. Depending on the molecular mechanisms underlying their action, Ca(2+)-sensitisers have been divided into three classes. While, a number of Ca(2+)-sensitising drugs have been described, currently only the Ca(2+)-sensitisers pimobendan and levosimendan are in clinical use. This review provides a survey on the molecular mechanisms and the therapeutic effectiveness of Ca(2+)-sensitisers for the treatment of human heart failure.

The utility of levosimendan in the treatment of heart failure

Calcium sensitizers are a new group of inotropic drugs. Levosimendan is the only calcium sensitizer in clinical use in Europe. Its mechanism of action includes both calcium sensitization of contractile proteins and the opening of adenosine triphosphate (ATP)-dependent potassium channels as mechanism of vasodilation. The combination of K-channel opening with positive inotropy offers potential benefits in comparison to currently available intravenous inotropes, since K-channel opening protects myocardium during ischemia. Due to the calcium-dependent binding of levosimendan to troponin C, the drug increases contractility without negative lusitropic effects. In patients with heart failure levosimendan dose-dependently increases cardiac output and reduces pulmonary capillary wedge pressure. Since levosimendan has an active metabolite OR-1896 with a half-life of some 80 hours, the duration of the hemodynamic effects significantly exceeds the 1-hour half-life of the parent compound. The hemodynamic effects of the levosimendan support its use in acute and postoperative heart failure. Several moderate-size trials (LIDO, RUSSLAN, CASINO) have previously suggested that the drug might even improve the prognosis of patients with decompensated heart failure. These trials were carried out in patients with high filling pressures. Recently two larger trials (SURVIVE and REVIVE) in patients who were hospitalized because of worsening heart failure have been finalized. These trials did not require filling pressures to be measured. The two trials showed that levosimendan improves the symptoms of heart failure, but does not improve survival. The results raise the question whether a 24-hour levosimendan infusion can be used without invasive hemodynamic monitoring.

Management of fluid overload in congestive heart failure: learning from a case report

A case of refractory fluid overload due to congestive heart failure and consequent renal insufficiency is reported. The case was approached multidisciplinarily, at the beginning with conservative and pharmacological therapy, subsequently with extracorporeal fluid removal in which a specific attention was payed to the maintenance of circulating blood volume and achievement of dry weight, and finally with chronic peritoneal dialysis as a maintenance therapy. The case seems to summarize the pathway of many patients seen initially in intensive care and cardiology departments and subsequently in nephrological wards.

Pharmacological Mechanisms Contributing to the Clinical Efficacy of Levosimendan

Acute decompensation of chronic heart failure is a direct life-threatening situation with short-term mortality approaching 30%. A number of maladaptive changes are amplified within the cardiovascular system during the progression of chronic heart failure that makes the decompensation phase difficult to handle. Levosimendan is a new Ca2+-sensitizer for the treatment of acutely decompensated heart failure that has proved to be effective during the decompensation of chronic heart failure and acute myocardial infarction. Levosimendan differs from other cardiotonic agents that are used for acute heart failure in that it utilizes a unique dual mechanism of action: Ca2+-sensitization through binding to troponin C in the myocardium, and the opening of ATP-sensitive K+ channels in vascular smooth muscle. In general, these mechanisms evoke positive inotropy and vasodilation. Clinical studies suggested long-term benefits on mortality following short-term administration. It may, therefore, be inferred that levosimendan has additional effects on the cardiovascular system that are responsible for the prolongation of survival. Results of preclinical and clinical investigations suggest that the combination of levosimendan-induced cardiac and vascular changes has favorable effects on the coronary, pulmonary and peripheral circulations. Redistribution of the circulating blood offers an improved hemodynamic context for the development of a positive inotropic effect through Ca2+-sensitization of the contractile filaments, without a proportionate increase in myocardial oxygen consumption or the development of arrhythmias. Activation of ATP-sensitive K+ channels, both on sarcolemma and mitochondria, may protect against myocardial ischemia, and decreased levels of cytokines may prevent the development of further myocardial remodeling. Collectively, these effects of levosimendan shift the disturbed cardiovascular parameters towards normalization, thereby halting the perpetuation of the vicious cycle of heart failure progression. This may contribute to stabilization of the circulation and improved life expectancy of patients with chronic heart failure.

Levosimendan in Cardiac Surgery: Current Best Available Evidence

Recent upsurge in referral of patients with high perioperative risk or compromised left ventricular function for cardiac surgery has lead to an increasing use of pharmacologic support in the form of vasodilator and inotropic therapy to achieve improvement of tissue perfusion in the perioperative period or to support weaning from cardiopulmonary bypass. Traditionally, perioperatively used inotropic agents, epinephrine, dobutamine, and milrinone, are limited by significant increases in myocardial oxygen consumption, proarrhythmia, or neurohormonal activation. Levosimendan, a new inodilator for the treatment of decompensated heart failure, has also shown promise in elective therapy of cardiac surgical patients with high perioperative risk or compromised left ventricular function, as well as in rescue therapy of patients with difficult weaning from cardiopulmonary bypass. This review article briefly discusses the pharmacology of levosimendan and evaluates current best available evidence to assess the safety and efficacy of levosimendan usage in cardiac surgery.

Levosimendan for the treatment of acute heart failure syndromes

Levosimendan is a novel calcium-sensitising agent that has been shown to have beneficial inotropic, metabolic and vasodilatory effects in the treatment of acute and advanced chronic heart failure. Levosimendan binds to troponin-C in cardiomyocytes and, thereby, improves cardiac contractility without disturbing the metabolic status of the heart and increasing myocardial oxygen demand or provoking fatal cardiac arrhythmias. Levosimendan also opens ATP-sensitive potassium channels, causing peripheral arterial and venous dilatation, and increasing coronary flow reserve. When it is given as a short-term therapy, levosimendan enhances cardiac output, reduces systemic vascular resistance and lowers pulmonary capillary wedge pressure. Clinical outcomes were significantly reduced in decompensated or postmyocardial infarction heart failure patients who received levosimendan, compared with those on dobutamine or placebo. Recent investigations focusing on the anti-inflammatory and antiapoptotic actions of levosimendan in the failing heart indicate that improvement of cardiac contractile performance is closely related with the drug-induced reduction of circulating pro-inflammatory cytokines and apoptosis inducers. The most common adverse effects of levosimendan treatment are hypotension and headache. Overall, levosimendan represents an effective and safe option for the treatment of decompensated heart failure patients.

Levosimendan: a novel inotropic agent for treatment of acute, decompensated heart failure

OBJECTIVE

To review the literature on a novel calcium sensitizer, levosimendan.

DATA SOURCES

Articles were identified through searches of MEDLINE (1966-June 2005), International Pharmaceutical Abstracts (1970-June 2005), and EMBASE (1992-June 2005) using the key words levosimendan, simendan, calcium sensitizer, calcium sensitiser, and congestive heart failure.

STUDY SELECTION AND DATA EXTRACTION

Clinical trials and pharmacokinetic studies evaluating the safety and efficacy of levosimendan were selected.

DATA SYNTHESIS

Levosimendan 6-24 mug/kg intravenous bolus followed by a 24-hour continuous infusion of 0.05-0.2 microg/kg/min improved cardiac output and reduced pulmonary capillary wedge pressure in a dose-dependent manner. Dose-ranging and randomized clinical trials have demonstrated improvement in symptoms and hemodynamics and short-term survival outcomes in the treatment of acute, decompensated heart failure. Clinical trials evaluating retrospective mortality data and combined endpoints (mortality, rehospitalization) have demonstrated better outcomes with levosimendan compared with dobutamine. The incidence of hypotension with levosimendan is not significantly different than with dobutamine, but there is a dose-related increase in heart rate.

CONCLUSIONS

Levosimendan is useful in moderate to severe low-output heart failure in patients who have failed to respond to diuretics and vasodilators. Based on current studies, levosimendan appears to be a safe alternative to dobutamine for treatment of acute, decompensated heart failure. Prospective clinical trials are needed to confirm the effect of levosimendan on long-term survival and its role in heart failure in the setting of myocardial infarction.

Effects of Levosimendan on Restrictive Left Ventricular Filling in Severe Heart Failure

BACKGROUND

A restrictive pattern of left ventricular filling is often present in patients with severe heart failure. Although the hemodynamic effects of levosimendan have been studied, the effects of levosimendan on LV filling pattern have not been investigated.

METHODS

Pulsed-wave Doppler mitral (transthoracic) and pulmonary venous flow (transesophageal) velocity curves were recorded in 30 patients with a restrictive pattern of left ventricular filling with New York Heart Association class III or IV heart failure who had a documented left ventricular ejection fraction < 30% by echocardiography and received a 0.1 microg/kg/min infusion of levosimendan for 24 h.

RESULTS

Levosimendan caused significant (p < 0.001) increases in stroke volume (from 46 +/- 4 to 57 +/- 4 mL) and decreases in pulmonary capillary wedge pressure (from 21 +/- 1 to 15 +/- 1 mm Hg). The E wave decreased (from 96 +/- 7 to 71 +/- 5 cm/s), and the A wave increased (from 40 +/- 4 to 46 +/- 4 cm/s). Moreover, deceleration time was increased (from 112 +/- 7 to 189 +/- 14 ms). The S wave of pulmonary venous flow was increased (from 38 +/- 3 to 60 +/- 3 cm/s), and atrial reversal was decreased (from 36 +/- 2 to 29 +/- 2 cm/s). All changes were significant (p < 0.001). Using stepwise linear regression analysis, we found that the percentage changes of the early/late transmitral diastolic peak flow velocity (E/A) ratio and the percentage changes of the isovolumetric relaxation time were independent predictors of the increase in cardiac output. Furthermore, the percentage changes of the systolic/diastolic ratio and the percentage changes of the E/A ratio were independent predictors of the decrease in pulmonary capillary wedge pressure.

CONCLUSIONS

Treatment with levosimendan improved measures of left ventricular diastolic function. Consequently, left ventricular stroke volume was increased.