June 29, 2022

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What is the difference between dopamine and dobutamine?

What is the difference between dopamine and dobutamine?



 

What is the difference between dopamine and dobutamine? How to use it clinically?

Dopamine and dobutamine are both β-adrenergic agonists and are currently widely used clinically inotropic catecholamine drugs. So what is the difference between the two in use?

 

01. Pharmacological effects

 

1) Dopamine

• Small dose (generally instillation speed <3 μg/kg•min): Mainly dopamine-like agonist, with mild positive muscle strength and renal vasodilation;

• At moderate doses (generally instillation speed 3~5 μg/kg•min), β receptors are mainly excited, which can increase myocardial contractility and cardiac output;

• At larger doses (generally instillation rate > 5 μg/kg•min): α receptor agonistic effect dominates, peripheral vascular resistance increases, renal vasoconstriction, renal blood flow and urine output decrease instead.

 

2)Dobutamine

It mainly activates β₁ receptors and has minimal effect on β₂ and α receptors.

It has a strong positive inotropic effect, enhances myocardial contraction, reduces systemic vascular resistance and pulmonary capillary wedge pressure, increases stroke volume and cardiac output, improves peripheral perfusion, and reduces left ventricular filling pressure.

 

02. Clinical application

 

1)Dopamine

Mainly used for shock syndrome caused by myocardial infarction, trauma, endotoxin sepsis, heart surgery, renal failure, congestive heart failure, etc.; shock that cannot be corrected after blood volume supplementation, especially for oliguria and normal or relatively normal peripheral vascular resistance Low shock; cardiac insufficiency where digitalis and diuretics are ineffective.

 

2)Dobutamine

Mainly used for severe systolic heart failure, such as heart failure caused by decreased myocardial contractility in patients with organic heart disease (including low output syndrome after open heart surgery); cardiogenic shock; stress ultrasound Cardiogram test.

 

 

 

03. Common dosage

 

1)Dopamine

• The treatment of shock and heart failure is started with a small dose (infusion rate of 3 μg/kg•min) and gradually adjusted according to the condition. The maximum infusion rate is 20 μg/kg•min, and when the infusion rate is> 10 μg/kg•min, Peripheral vasoconstriction is obvious, which increases the risk of organ ischemia.

• The infusion rate for cardiogenic shock is 0.5~2.0 μg/kg•min.

 

2) Dobutamine

• The initial drip rate for the treatment of heart failure is 2.5 μg/kg•min, generally maintained at 2.5-10 μg/kg•min. If the patient can tolerate it and needs it, the drip rate can be gradually increased to 20 μg/kg•min , Generally, the continuous medication time does not exceed 3 to 7 days.

• The infusion rate for the treatment of cardiogenic shock is 2.5-20 μg/kg•min. The specific treatment time and administration rate are determined by the patient’s response (such as heart rate, blood pressure, urine output, and whether ectopic beats occur).

 

04. Matters needing attention

 

1) Dopamine

• There are two types of medicine: water injection and powder injection. The auxiliary material of water injection is sodium bisulfite, which can cause allergic reactions, such as inducing or aggravating asthma. Those with a history of sodium bisulfite allergy should not use dopamine water injection containing this substance. .

In order to improve the safety of medication and the stability of drug components, dopamine powder injections with higher purity imported raw materials should be selected first.

• This drug can aggravate angina pectoris due to tachyarrhythmia; pheochromocytoma should not be used; use with caution in obstructive vascular disease; monitor blood pressure, cardiac output, electrocardiogram and urine output when using it, and correct hypovolemia before medication.

• During intravenous infusion, if the blood pressure continues to drop or there is no improvement after the dose is adjusted, you should stop using a stronger vasoconstrictor.

• Abrupt discontinuation of the drug can produce severe hypotension, and gradually reduce the dose when stopping. The drug should be discontinued when the drug is overdose, and α-adrenergic receptor blockers should be given if necessary.

• The more severe the heart failure, the lower the patient’s responsiveness to dopamine, and the dose of dopamine should be increased.

 

2) Dobutamine

• Monitor blood pressure, heart rate and rhythm during use, and correct hypovolemia before medication.

• For patients with severe heart failure, continuous intravenous application will increase the risk of death.

• Increase in systolic blood pressure and increase in heart rate during medication, so the dose should be reduced or the medication should be suspended. The dose should be gradually reduced when stopping the drug.

• The glucose injection of this medicine contains sodium bisulfite, which may cause allergic reactions in some sensitive patients.

• The drug has a short half-life and must be administered by continuous intravenous drip. After starting the constant-rate infusion or changing the infusion rate, the plasma concentration can reach a steady state within about 10 minutes. It is not recommended to give loading doses or high-dose rapid injections.

 

In addition, for patients who are using β-blockers (such as patients with acute decompensated chronic heart failure), dopamine and dobutamine are not recommended first.

 

 

 

(source:internet, reference only)


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