Pimobendan

Abstract

Pimobendan is a novel cardiotonic vasodilator (inodilator) which derives its inotropic activity from a combination of phosphodiesterase III inhibition and sensitisation of myocardial contractile proteins to calcium. The acute haemodynamic benefits of pimobendan (2.5 to 10mg orally; 5 to 10mg intravenously) seen in patients maintained on conventional diuretic, digitalis and vasodilator therapy for chronic heart failure (increases in cardiac output and stroke volume, and reductions in left ventricular preload and afterload) persisted on short term (1 month) therapy, and showed only limited evidence of attenuation on longer term (6 months) oral therapy with pimobendan 2.5 or 5mg twice daily. Adjunctive therapy with pimobendan 1.25 to 5mg twice daily for periods of 3 to 6 months improved exercise tolerance on symptom-limited exercise testing, New York Heart Association (NYHA) functional class, and quality of life, and additionally reduced the need for hospitalisation in patients with moderate to severe chronic heart failure. Pimobendan appears to be well tolerated at therapeutic doses (1.25 to 5mg twice daily) in patients with chronic heart failure, and preliminary indications suggest that it is largely devoid of the proarrhythmic effects of classical phosphodiesterase III inhibitors. Although information regarding the long term effects of pimobendan on mortality is currently lacking, the drug nevertheless shows potential benefit as an adjunctive therapy in patients with chronic heart failure.

Acute Effects of Pimobendan on Cardiac Function in Dogs With Tachycardia Induced Dilated Cardiomyopathy: A Randomized, Placebo-Controlled, Crossover Study

“…This phosphodiesterase-3 inhibitor and calcium sensitizer medication has complex effects, and the exact mechanism(s) by which it improves clinical signs and survival remain to be defined. Pimobendan exerts direct effects on both the myocardium and the vasculature, and is described as an “inodilator”—both a positive inotrope and vasodilator ( 3 , 4 ). While its effects on improving ventricular systolic function are well-known, it has also been suggested that its load modulating properties (e.g., decreased vascular resistance) may be equally or more important in the setting of dilated cardiomyopathy (DCM), characterized by volume/fluid overload ( 1 , 5 ).…”

Successful Identification of Cardiac Troponin Calcium Sensitizers Using a Combination of Virtual Screening and ROC Analysis of Known Troponin C Binders

“…22 It has undergone clinical trials and is currently used in veterinary medicine as a treatment for congestive heart failure in canines. 23–25 Another calcium sensitizing compound more recently discovered is NSC147866 which has been shown to bind to both cNTnC and the cNTnC-cTnI 147-163 complex. 10, 26 Other compounds reported to bind to the hydrophobic pocket of cNTnC are bepridil 10, 22, 27 , W7 10, 28 , DFBP-O 10, 26, 29 , and trifluoperazine 22, 27, 30 .…”

Hypoglycemia after Mitral Valve Repair in Dogs

“…The authors considered the possibility of medications used during the perioperative period being related to hypoglycemia. All dogs in this study were on pimobendan, which has insulinotropic properties [ 28 ], but the postoperative decrease in insulin levels implies lack of excessive insulinotropic actions. ACD-A was used as an anticoagulant during blood collection for autologous blood transfusion, and MAP was used as a blood preservation solution for allogeneic blood.…”