Dobutamine

Dobutamine has predominant B1 effects that increase heart rate and force of contraction. It also has mild B2 and a1 effects and decreases peripheral and pulmonary vascular resistance. Systolic BP may be increased because of the augmented cardiac output. Dobutamine has no specific effects on renal or splanchnic blood flow, but may increase renal blood flow due to an increase in cardiac output.

Uses:
Low cardiac output states

Contraindications:
Before adequate intravascular volume replacement Idiopathic hypertrophic subaortic stenosis

Administration:
• IV infusion: 1–25 μg/kg/min via a central vein
Titrate dose according to HR, BP, cardiac output, presence of ectopic beats and urine output 250 mg made up to 50 ml glucose 5% or sodium chloride 0.9%
(5000 μg/ml)

Dosage chart (ml/h)

Weight (kg)	Dose (ug/kg/min)
	2.5	5.0	7.5	10	15	20
50	1.5	3.0	4.5	6.0	9.0	12.0
60	1.8	3.6	5.4	7.2	10.8	14.5
70	2.1	4.2	6.3	8.4	12.75	16.8
80	2.4	4.8	7.2	9.6	14.4	19.2
90	2.7	5.4	8.1	10.8	16.2	21.6
100	3.0	6.0	9.0	12.0	18.0	24.0
110	3.3	6.6	9.9	13.2	19.8	26.4
120	3.6	7.2	10.8	14.4	21.6	28.8

How not to use dobutamine
In the absence of invasive cardiac monitoring
Inadequate correction of hypovolaemia before starting dobutamine
Do not connect to CVP lumen used for monitoring pressure (surge of drug during flushing of line)
Incompatible with alkaline solutions,e.g.sodium bicarbonate, furosemide, phenytoin and enoximone

Adverse effects
Tachycardia
Ectopic beats

Cautions
Acute myocardial ischaemia or MI
B-Blockers (may cause dobutamine to be less effective)