Inotrope
Encyclopedia
An inotrope is an agent that alters the force or energy of muscular contractions. Negatively inotropic agents weaken the force of muscular
Muscle
Muscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...

 contractions. Positively inotropic agents increase the strength of muscular contraction.

The term inotropic state is most commonly used in reference to various drugs
Medication
A pharmaceutical drug, also referred to as medicine, medication or medicament, can be loosely defined as any chemical substance intended for use in the medical diagnosis, cure, treatment, or prevention of disease.- Classification :...

 that affect the strength of contraction of heart
Heart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...

 muscle (myocardial contractility). However, it can also refer to pathological conditions. For example, enlarged heart muscle (ventricular hypertrophy
Ventricular hypertrophy
Ventricular hypertrophy is the enlargement of ventricles in the heart. Although left ventricular hypertrophy is more common, enlargement can also occur in the right ventricle, or both ventricles.- Physiology :...

) can increase inotropic state, whereas dead heart muscle (myocardial infarction
Myocardial infarction
Myocardial infarction or acute myocardial infarction , commonly known as a heart attack, results from the interruption of blood supply to a part of the heart, causing heart cells to die...

) can decrease it.

Cardiac inotropes

Both positive and negative inotropes are used in the management of various cardiovascular conditions. The choice of agent depends largely on specific pharmacological effects of individual agents with respect to the condition. One of the most important factors affecting inotropic state is the level of calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...

 in the cytoplasm
Cytoplasm
The cytoplasm is a small gel-like substance residing between the cell membrane holding all the cell's internal sub-structures , except for the nucleus. All the contents of the cells of prokaryote organisms are contained within the cytoplasm...

 of the muscle cell. Positive inotropes usually increase this level, while negative inotropes decrease it. However, not all drugs involve calcium release, and, among those that do, the mechanism for manipulating the calcium level can vary from drug to drug.

Positive inotropic agents

Positive inotropic agents increase myocardial contractility, and are used to support cardiac function in conditions such as decompensated
Decompensation
In medicine, decompensation is the functional deterioration of a previously working structure or system. Decompensation may occur due to fatigue, stress, illness, or old age. When a system is "compensated," it is able to function despite stressors or defects. Decompensation describes an inability...

 congestive heart failure
Congestive heart failure
Heart failure often called congestive heart failure is generally defined as the inability of the heart to supply sufficient blood flow to meet the needs of the body. Heart failure can cause a number of symptoms including shortness of breath, leg swelling, and exercise intolerance. The condition...

, cardiogenic shock
Cardiogenic shock
Cardiogenic shock is based upon an inadequate circulation of blood due to primary failure of the ventricles of the heart to function effectively....

, septic shock
Septic shock
Septic shock is a medical emergency caused by decreased tissue perfusion and oxygen delivery as a result of severe infection and sepsis, though the microbe may be systemic or localized to a particular site. It can cause multiple organ dysfunction syndrome and death...

, myocardial infarction
Myocardial infarction
Myocardial infarction or acute myocardial infarction , commonly known as a heart attack, results from the interruption of blood supply to a part of the heart, causing heart cells to die...

, cardiomyopathy
Cardiomyopathy
Cardiomyopathy, which literally means "heart muscle disease," is the deterioration of the function of the myocardium for any reason. People with cardiomyopathy are often at risk of arrhythmia or sudden cardiac death or both. Cardiomyopathy can often go undetected, making it especially dangerous to...

, etc.

Examples of positive inotropic agents include:
  • Berberine
    Berberine
    Berberine is a quaternary ammonium salt from the protoberberine group of isoquinoline alkaloids. It is found in such plants as Berberis Berberine is a quaternary ammonium salt from the protoberberine group of isoquinoline alkaloids. It is found in such plants as Berberis Berberine is a quaternary...

  • Bipyridine
    Bipyridine
    Bipyridines are a family of chemical compounds with the formula 2, which are formed by the coupling of two pyridine rings. Six isomers of bipyridine exist, but two isomers are prominent: 2,2'-bipyridine is a popular ligand in coordination chemistry and 4,4'-bipyridine is a precursor to the...

     derivatives
    • Inamrinone
    • Milrinone
      Milrinone
      Milrinone is a phosphodiesterase 3 inhibitor. It potentiates the effect of cyclic adenosine monophosphate .Milrinone also enhances contraction of the left ventricle by increasing Ca2+-ATPase activity on the cardiac sarcoplasmic reticulum...

  • Calcium
    Calcium
    Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...

  • Calcium sensitisers
    • Levosimendan
      Levosimendan
      Levosimendan is a calcium sensitiser used in the management of acutely decompensated congestive heart failure. It is marketed under the trade name Simdax .-Mode of action:...

  • Catecholamine
    Catecholamine
    Catecholamines are molecules that have a catechol nucleus consisting of benzene with two hydroxyl side groups and a side-chain amine. They include dopamine, as well as the "fight-or-flight" hormones adrenaline and noradrenaline released by the adrenal medulla of the adrenal glands in response to...

    s
    • Dopamine
      Dopamine
      Dopamine is a catecholamine neurotransmitter present in a wide variety of animals, including both vertebrates and invertebrates. In the brain, this substituted phenethylamine functions as a neurotransmitter, activating the five known types of dopamine receptors—D1, D2, D3, D4, and D5—and their...

    • Dobutamine
      Dobutamine
      Dobutamine is a sympathomimetic drug used in the treatment of heart failure and cardiogenic shock. Its primary mechanism is direct stimulation of β1 receptors of the sympathetic nervous system. Dobutamine was developed by a laboratory led by Drs...

    • Dopexamine
      Dopexamine
      Dopexamine is a β2-adrenergic receptor agonist. It also acts at dopamine receptors.Use in sepsis has been proposed.It is considered a inotropic agent....

    • Epinephrine
      Epinephrine
      Epinephrine is a hormone and a neurotransmitter. It increases heart rate, constricts blood vessels, dilates air passages and participates in the fight-or-flight response of the sympathetic nervous system. In chemical terms, adrenaline is one of a group of monoamines called the catecholamines...

       (adrenaline)
    • Isoprenaline (isoproterenol)
    • Norepinephrine
      Norepinephrine
      Norepinephrine is the US name for noradrenaline , a catecholamine with multiple roles including as a hormone and a neurotransmitter...

       (noradrenaline)
  • Digoxin
    Digoxin
    Digoxin INN , also known as digitalis, is a purified cardiac glycoside and extracted from the foxglove plant, Digitalis lanata. Its corresponding aglycone is digoxigenin, and its acetyl derivative is acetyldigoxin...

  • Digitalis
    Digitalis
    Digitalis is a genus of about 20 species of herbaceous perennials, shrubs, and biennials that are commonly called foxgloves. This genus was traditionally placed in the figwort family Scrophulariaceae, but recent reviews of phylogenetic research have placed it in the much enlarged family...

  • Eicosanoid
    Eicosanoid
    In biochemistry, eicosanoids are signaling molecules made by oxidation of twenty-carbon essential fatty acids, ....

    s

    • Prostaglandin
      Prostaglandin
      A prostaglandin is any member of a group of lipid compounds that are derived enzymatically from fatty acids and have important functions in the animal body. Every prostaglandin contains 20 carbon atoms, including a 5-carbon ring....

      s
  • Phosphodiesterase inhibitors
    • Enoximone
      Enoximone
      Enoximone is an imidazole phosphodiesterase inhibitor. It is used in the treatment of congestive heart failure. Selective for phosphodiesterase 3...

    • Milrinone
      Milrinone
      Milrinone is a phosphodiesterase 3 inhibitor. It potentiates the effect of cyclic adenosine monophosphate .Milrinone also enhances contraction of the left ventricle by increasing Ca2+-ATPase activity on the cardiac sarcoplasmic reticulum...

    • Theophylline
      Theophylline
      Theophylline, also known as dimethylxanthine, is a methylxanthine drug used in therapy for respiratory diseases such as COPD and asthma under a variety of brand names. Because of its numerous side-effects, the drug is now rarely administered for clinical use. As a member of the xanthine family, it...

  • Glucagon
    Glucagon
    Glucagon, a hormone secreted by the pancreas, raises blood glucose levels. Its effect is opposite that of insulin, which lowers blood glucose levels. The pancreas releases glucagon when blood sugar levels fall too low. Glucagon causes the liver to convert stored glycogen into glucose, which is...


Negative inotropic agents

Negative inotropic agents decrease myocardial contractility, and are used to decrease cardiac workload in conditions such as angina. While negative inotropism may precipitate or exacerbate heart failure, certain beta blockers (e.g. carvedilol
Carvedilol
Carvedilol is a non-selective beta blocker/alpha-1 blocker indicated in the treatment of mild to moderate congestive heart failure . It is marketed under various trade names including Carvil , Coreg , Dilatrend , Eucardic , and Carloc as a generic drug ., and as a...

, bisoprolol and metoprolol) have been shown to reduce morbidity and mortality
Death
Death is the permanent termination of the biological functions that sustain a living organism. Phenomena which commonly bring about death include old age, predation, malnutrition, disease, and accidents or trauma resulting in terminal injury....

 in congestive heart failure
Congestive heart failure
Heart failure often called congestive heart failure is generally defined as the inability of the heart to supply sufficient blood flow to meet the needs of the body. Heart failure can cause a number of symptoms including shortness of breath, leg swelling, and exercise intolerance. The condition...

.
Cardiac glycoside
Cardiac glycoside
Cardiac glycosides are drugs used in the treatment of congestive heart failure and cardiac arrhythmia. These glycosides are found as secondary metabolites in several plants, but also in some animals, such as the milkweed butterflies. -Function:...

s
  • Beta blocker
    Beta blocker
    Beta blockers or beta-adrenergic blocking agents, beta-adrenergic antagonists, beta-adrenoreceptor antagonists or beta antagonists, are a class of drugs used for various indications. They are particularly for the management of cardiac arrhythmias, cardioprotection after myocardial infarction ,...

    s
  • Calcium channel blocker
    Calcium channel blocker
    A calcium channel blocker is a chemical that disrupts the movement of calcium through calcium channels.CCB drugs devised to target neurons are used as antiepileptics. However, the most widespread clinical usage of calcium channel blockers is to decrease blood pressure in patients with...

    s
    • Diltiazem
      Diltiazem
      Diltiazem is a non-dihydropyridine member of the class of drugs known as calcium channel blockers, used in the treatment of hypertension, angina pectoris, and some types of arrhythmia....

    • Verapamil
      Verapamil
      Verapamil is an L-type calcium channel blocker of the phenylalkylamine class. It has been used in the treatment of hypertension, angina pectoris, cardiac arrhythmia, and most recently, cluster headaches. It is also an effective preventive medication for migraine...

    • Clevidipine
      Clevidipine
      Clevidipine is a dihydropyridine calcium channel blocker indicated for the reduction of blood pressure when oral therapy is not feasible or not desirable....



Class IA antiarrhythmics such as
  • Quinidine
    Quinidine
    Quinidine is a pharmaceutical agent that acts as a class I antiarrhythmic agent in the heart. It is a stereoisomer of quinine, originally derived from the bark of the cinchona tree.-Mechanism:...

  • Procainamide
    Procainamide
    Procainamide INN is a pharmaceutical antiarrhythmic agent used for the medical treatment of cardiac arrhythmias, classified by the Vaughan Williams classification system as class Ia.-History:...

  • disopyramide
    Disopyramide
    Disopyramide is an antiarrhythmic medication. It is a Class Ia antiarrhythmic used in the treatment of ventricular tachycardias...



Class IC antiarrhythmics such as
  • Flecainide
    Flecainide
    Flecainide acetate is a class Ic antiarrhythmic agent used to prevent and treat tachyarrhythmias . It is used to treat a variety of cardiac arrhythmias including paroxysmal atrial fibrillation , paroxysmal supraventricular tachycardia Flecainide acetate is a class Ic antiarrhythmic agent used to...

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