American Journal of Pharmacology and Pharmacotherapeutics www.pubicon.in American Journal of Pharmacology and Pharmacotherapeutics Cardiovascular Effect of Pyridazine Derivative Pimobedan and Other Related Compounds Mohammad Asif* Department of Pharmacy, GRD (PG) IMT, Dehradun, 248009 Uttarakhand, India *Corresponding author e-mail: aasif321@gmail.com A B S T R A C T The pyridazine ring is present in various biologically active compounds and some pyridazine compounds have been reported as valuable cardiovascular agents. Benzimidazole-pyridazinone compound, 4,5-dihydro-6-[2-(4-methoxyphenyl)-1H-benzimidazole-5-yl]-5-methyl-3(2H)- pyridazinone (pimobedan or vetmedin) is a potent cardiovascular agent. It is a non adrenergic, non-glycoside inotropic drug with vasodilator activities and exerts a stimulatory myocardial activity by a dual mechanism of action with raise in calcium sensitivity of cardiac myofilaments and inhibition of phosphodiesterase. Pyridazine is an attractive compound for designing and development of novel pyridazine compounds as cardiotonic agents in future. Keywords: Pimobendan, cardiovascular, vasodilatative, phosphodiesterase, calcium sensitiser. INTRODUCTION Nowadays cardiovascular diseases (CVD) are major public health problem wordwide, in this regards ischemic heart disease (IHD) or coronary heart disease (CHD) is more common. 1 The prevalence is increasingly occurs in the elderly population. 2 The common cause is coronary artery disease (CAD), either alone or in combination with hypertension. Other factors, likes hypercholesterolaemia, diabetes mellitus, obesity and smoking may raise the risk of rising this syndrome. Indications of heart failure (HF) contain fatigue, anorexia, limited exercise tolerance, and dyspnoea 3 . This results from myocardial ischaemia (MI), arrhythmias, non- compliance with treatment or intercurrent infections. Acute heart failure (AHF) may also arise suddenly following a cardiac insult in a patient without previous evidence of overt CVD. About 15% of worldwide mortality is attributable to heart disease (HD) 4 . It is estimated that HD will be the biggest cause of disease burden worldwide By 2020 5,6 . The IHD is the most important and most common contributor to the development of HF. 7,8 Treatment with positive inotropic agents is indicated for Review Article