Should I add dobutamine to a patient already on multiple inotropes, including epinephrine?

Adding Dobutamine to a Patient Already on Multiple Inotropes Including Epinephrine

Dobutamine should not be added to a patient already on multiple inotropes including epinephrine, as it may antagonize epinephrine's effects and provide no additional hemodynamic benefit while increasing the risk of arrhythmias.

Rationale for Not Adding Dobutamine

• Dobutamine can inhibit epinephrine-induced production of cAMP in human cells and appears to have subadditive clinical effects when combined with epinephrine 1
• When epinephrine is combined with moderate to high doses of dobutamine (2.5-5 μg/kg/min), there is no additional increase in cardiac index beyond what is achieved with epinephrine and the lowest dose of dobutamine 1
• Inotropes, especially those with adrenergic mechanisms like dobutamine, can cause sinus tachycardia and may induce myocardial ischemia and arrhythmias 2
• There is long-standing concern that inotropes may increase mortality in heart failure patients 2

Current Recommendations for Inotrope Use

• Inotropes should be reserved for patients with severe reduction in cardiac output resulting in compromised vital organ perfusion, which occurs most often in hypotensive acute heart failure 2
• When a patient is already on epinephrine, adding dobutamine provides little additional benefit due to their pharmacological interaction 1
• For patients requiring multiple vasopressors/inotropes, norepinephrine is recommended as the first-line vasopressor due to fewer side effects and potentially lower mortality compared to dopamine 2, 3
• If additional inotropic support is needed beyond epinephrine, consider alternative agents such as milrinone or levosimendan rather than dobutamine 2, 3

Risks of Multiple Inotrope Therapy

• Prolonged infusion of dobutamine (>24-48 hours) is associated with tolerance and partial loss of hemodynamic effects 2, 4
• Dobutamine increases the incidence of arrhythmias originating from both ventricles and atria, with this effect being dose-related 2
• The FDA label for dobutamine notes that it has not been shown in controlled trials to be safe or effective in the long-term treatment of heart failure 5
• Multiple inotropes can lead to excessive tachycardia, myocardial ischemia, and increased myocardial oxygen demand 2

Alternative Approaches

• If the patient has low systemic vascular resistance, consider adding a vasopressor such as norepinephrine instead of another inotrope 2, 3
• For patients with persistent hypotension despite adequate cardiac filling pressures and current inotropes, consider vasopressin as an additional agent 2
• In cases of cardiogenic shock where multiple inotropes are failing, mechanical circulatory support should be considered rather than adding more inotropes 3
• For patients on beta-blockers, levosimendan may be preferable to dobutamine to reverse the effect of beta-blockade 2

Special Considerations

• If the patient is already on epinephrine, adding dobutamine may actually reduce the effectiveness of epinephrine through pharmacological antagonism 1
• Hypovolemia should be corrected with suitable volume expanders before considering additional inotropic support 5
• No improvement may be observed with dobutamine in the presence of marked mechanical obstruction, such as severe valvular aortic stenosis 5
• If the patient has atrial fibrillation, dobutamine may facilitate conduction through the AV node and lead to dangerous tachycardia 4