II. Mechanism
- Synthetic Catecholamine (Sympathomimetic amine) derived from Dopamine
- Overall effect similar to Dopamine with Nitroprusside
- Selective for Beta Adrenergic Receptors (primarily B1)
- Beta 1 Adrenergic Receptor (potent)
- Increased cardiac contractility, but minimal increase in Heart Rate
- Beta 2 Adrenergic Receptor (weak)
- Mild increase in vasodilation
- Does not directly affect renal or splanchnic flow
- Beta 1 Adrenergic Receptor (potent)
- Relatively mild Alpha 1 Adrenergic Receptor effect
- Vasoconstriction countered by more potent beta effect
- No significant impact on Peripheral Vascular Resistance
- No Dopaminergic Receptor activity (unlike Dopamine)
- Minimal effects on myocardial oxygen demand
- Favorable balance between oxygen supply and demand
- Preferred in Cardiogenic Shock over Dopamine
- Increased perfusion balances inotropic strain
- Benefit lost if not titrated to avoid Tachycardia
- Does not increase infarct size
- Does not elicit Arrhythmia
- Favorable balance between oxygen supply and demand
III. Pharmacokinetics
- Short Half-Life
- As with other Catecholamines, rapidly metabolized by COMT and MAO
- Only effective by infusion
IV. Indications
-
Cardiogenic Shock (Severe Congestive Heart Failure)
- Pulmonary congestion or Hypotension
- Right ventricular infarction
- Use with fluid Resuscitation
- Often used in combination with Dopamine
- Moderate dosages of each (7.5 ug/kg/min)
- Maintains critical organ perfusion
- Less pulmonary congestion than with Dopamine alone
- Not shown to alter mortality
- May alter secondary organ injury outcomes
- Not usually indicated in non-Cardiogenic Shock
- Other Catecholamines preferred in other shock types
- In Septic Shock, may be useful in enhancing left ventricular function
- However, Norepinephrine is preferred agent in fluid refractory Septic Shock
V. Dosing: Pediatric Infusion (Same as Dopamine preparation)
- Preparation
- Draw up "x" mg of Dobutamine
- Where "x" = 6 x Weight in Kilograms
- Add enough D5W or NS to Dobutamine for 100 ml total
- At this dilution
- Infusion rate of 1 ml/h provides 1.0 ug/kg/min
- Start Dose: 5-10 ug/kg/min or 5-10 ml/hour
- Titrate to clinical response (usually <20 ug/kg/min)
VI. Dosing: Adult Infusion
- Preparation
- Start with 2-4 ampules Dobutamine (250 mg each)
- Dissolve 500-1000 mg Dobutamine in 250 ml D5W or NS
- Final Concentration: 2000-4000 ug/ml
- Start Dose: 0.5 to 2.0 ug/kg/min
- Titrate: 2-20 ug/kg/min to clinical response
- Perfusion
- Urine Output
- Blood Pressure
- Avoid increasing Heart Rate 10% over baseline
VII. Adverse Effects
- Tachycardia
- Arrhythmia
- Ectopic beats
- Provokes Myocardial Ischemia if Tachycardia occurs
- Headache
- Nausea
- Tremor
- Hypokalemia
VIII. References
- Olson (2020) Clinical Pharmacology, Medmasters, Miami, p. 13-33
- Goldstein (2010) Clin Auton Res 20(6):331-52 +PMID: 20623313 [PubMed]