What are all the inotropes used for treating shock?

From the Guidelines

Inotropes used for treating shock include norepinephrine, epinephrine, dopamine, dobutamine, vasopressin, phenylephrine, milrinone, and levosimendan, with norepinephrine being the first-line agent for most shock types, especially septic shock, due to its strong alpha and moderate beta effects that increase blood pressure while supporting cardiac output 1.

Key Inotropes and Their Uses

• Norepinephrine (starting at 0.01-0.3 mcg/kg/min) is typically first-line for most shock types, especially septic shock, due to its strong alpha and moderate beta effects that increase blood pressure while supporting cardiac output.
• Epinephrine (0.01-0.5 mcg/kg/min) is useful in anaphylactic shock and as a second-line agent in septic shock.
• Dopamine (1-20 mcg/kg/min) has dose-dependent effects but has fallen out of favor due to increased arrhythmia risk.
• Dobutamine (2-20 mcg/kg/min) primarily increases cardiac output and is valuable in cardiogenic shock.
• Vasopressin (0.01-0.04 units/min) is often added as a catecholamine-sparing agent in septic shock.
• Phenylephrine (0.1-5 mcg/kg/min) is a pure alpha agonist used when tachycardia must be avoided.
• Milrinone (loading dose 50 mcg/kg, then 0.375-0.75 mcg/kg/min) and levosimendan (0.05-0.2 mcg/kg/min) are phosphodiesterase inhibitors that increase contractility without significantly increasing myocardial oxygen demand, making them useful in cardiogenic shock.

Mechanisms of Action

These medications work by various mechanisms including alpha and beta adrenergic stimulation, vasopressin receptor activation, or phosphodiesterase inhibition to increase cardiac contractility, heart rate, and/or vascular tone to improve tissue perfusion in shock states.

Clinical Considerations

The choice of inotrope should be guided by the underlying cause of shock, the patient's hemodynamic profile, and the potential risks and benefits of each medication, with a focus on minimizing morbidity, mortality, and improving quality of life 1.

From the FDA Drug Label

Milrinone lactate is a positive inotrope and vasodilator, with little chronotropic activity different in structure and mode of action from either the digitalis glycosides or catecholamines Clinical studies in patients with congestive heart failure have shown that milrinone lactate produces dose-related and plasma drug concentration-related increases in the maximum rate of increase of left ventricular pressure

The inotropes used for treating shock that are mentioned in the provided drug labels are:

• Milrinone: a positive inotrope and vasodilator, used to increase myocardial contractility in patients with congestive heart failure.
• Epinephrine: a catecholamine, used to treat hypotension associated with septic shock, although its primary use is as a vasopressor, it also has inotropic effects 2, 3.

From the Research

Inotropes Used for Treating Shock

The following inotropes are used for treating shock:

• Dobutamine 4, 5, 6, 7
• Milrinone 4, 6, 7
• Dopamine 4, 5, 6
• Epinephrine 4, 5, 6
• Levosimendan 4, 6
• Isoproterenol 6
• Omecamtiv mecarbil (OM) 6
• Istaroxime 6
• Nesiritide 6

Classification of Inotropes

Inotropes can be classified into different categories, including:

• Endogenous catecholamines (epinephrine, norepinephrine, and dopamine) 6
• Vasopressor agents (vasopressin, selepressin, phenylephrine) 6
• Calcium-sensitizing agents (levosimendan) 6
• Cardiac-specific myosin activators (omecamtiv mecarbil) 6

Use of Inotropes in Different Types of Shock

Inotropes are used in different types of shock, including:

• Cardiogenic shock 4, 5, 6, 7
• Septic shock 5, 6
• Hypovolemic shock 6