Dobutamine

Dobutamine is a synthetic catecholamine used for short-term intravenous inotropic support. Its principal veterinary applications are low-output cardiac failure and cardiovascular support during anesthesia, particularly in horses. Its predominantly beta1-mediated effect increases cardiac contractility, making it useful when inadequate forward flow reflects depressed myocardial performance.

Group

Beta-adrenergic inotrope

Mechanism of Action

Dobutamine stimulates myocardial beta1-adrenergic receptors, activating adenylyl cyclase and increasing intracellular cyclic AMP. Protein-kinase signaling increases calcium availability during contraction, strengthening myocardial contraction and potentially increasing stroke volume and cardiac output. The racemic drug also interacts with alpha- and beta2-adrenergic receptors, so vascular and heart-rate responses depend on exposure and the patient’s cardiovascular state.

Dose Rates

Dog

Use / stage	Dose	Route	Schedule	Instructions
Cardiac support	5–20 mcg/kg/min	IV	Continuous	Do not use in: Ventricular arrhythmias; Start low and titrate; doses as low as 2 mcg/kg/min have improved cardiac output.
Acute heart failure	5–40 mcg/kg/min	IV	Continuous	Titrate to perfusion response with ECG and blood-pressure monitoring. Rates above 20 mcg/kg/min in dogs increase tachycardia risk.
Shock after fluid resuscitation	5–15 mcg/kg/min	IV	Continuous	Titrate to perfusion response with ECG and blood-pressure monitoring. Rates above 20 mcg/kg/min in dogs increase tachycardia risk.
Decompensated heart failure	2–20 mcg/kg/min	IV	Continuous	Titrate to perfusion response with ECG and blood-pressure monitoring. Rates above 20 mcg/kg/min in dogs increase tachycardia risk.
Low cardiac output	2.5–10 mcg/kg/min	IV	Continuous	Titrate to perfusion response with ECG and blood-pressure monitoring. Rates above 20 mcg/kg/min in dogs increase tachycardia risk.
Inotropic support	1–10 mcg/kg/min	IV	Continuous	Titrate to perfusion response with ECG and blood-pressure monitoring. Rates above 20 mcg/kg/min in dogs increase tachycardia risk.

Cat

Use / stage	Dose	Route	Schedule	Instructions
Cardiac support	2 mcg/kg/min	IV	Continuous	Do not use in: Ventricular arrhythmias
Acute heart failure	5–15 mcg/kg/min	IV	Continuous	Start at the low end; cats are more susceptible to CNS adverse effects.
Inotropic support	1–3 mcg/kg/min	IV	Continuous	Start at the low end; cats are more susceptible to CNS adverse effects.
Inotropic support	1–5 mcg/kg/min	IV	Continuous	Start at the low end; cats are more susceptible to CNS adverse effects.

Horse

Use / stage	Dose	Route	Schedule	Instructions
Anesthetic cardiovascular support	0.5 mcg/kg/min	IV	Continuous	Do not use in: Ventricular arrhythmias
Heart failure	5–10 mcg/kg/min	IV	Continuous	Do not use in: Ventricular arrhythmias
Foal inotropic support	Reference only	IV		After volume replacement, one source gives 2–20 mcg/kg/min but another section gives 3–40 mcg/kg/min. These inconsistent endpoints are retained without selecting a new calculated range.

Indications

Short-term support of dogs and cats with acute low-output heart failure and depressed myocardial contractility.
Cardiovascular support of anesthetized horses and other veterinary patients when reduced contractility contributes to hypotension or poor perfusion.
Inotropic support in selected critically ill patients with myocardial dysfunction, including some cases of septic or cardiogenic circulatory failure.

Contraindications

Ventricular arrhythmias
Use requires controlled infusion and cardiovascular monitoring.

Interactions

MAO inhibitors increase adverse sympathomimetic effects.
Avoid bicarbonate and alkaline mixtures; do not share an incompatible line with heparin, penicillins or cephalosporins.

Adverse effects

Tachycardia, hypertension and ventricular arrhythmias

Preparations

Preparation	Form	Strength	Route
Dobutamine 250 mg/20 mL Concentrate; dilute before infusion.	Injection	250 mg / 20 mL	IV

Monitoring and Administration

Monitor ECG, heart rate, blood pressure and perfusion. Stop or reduce infusion if arrhythmias develop.

Concentrated vials require dilution; mild pink color may occur, but discard brown solution.