DOPAMINE HYDROCHLORIDE 1.6 mg/mL Injection, Solution

INDICATIONS & USAGE Dopamine Hydrochloride in 5% Dextrose Injection, USP is indicated for the correction of hemodynamic imbalances present in shock due to myocardial infarction, trauma, endotoxic septicemia, open heart surgery, renal failure and chronic cardiac decompensation as in refractory congestive failure. When indicated, restoration of circulatory volume should be instituted or completed with a suitable plasma expander or whole blood, prior to administration of dopamine hydrochloride. Patients most likely to respond to dopamine are those whose physiological parameters (such as urine flow, myocardial function and blood pressure) have not undergone extreme deterioration.

Reports indicate that the shorter the time between onset of signs and symptoms and initiation of therapy with volume restoration and dopamine, the better the prognosis. Poor Perfusion of Vital Organs: Although urine flow is apparently one of the better diagnostic signs for monitoring vital organ perfusion, the physician also should observe the patient for signs of reversal of mental confusion or coma. Loss of pallor, increase in toe temperature or adequacy of nail bed capillary filling also may be observed as indices of adequate dosage.

Reported studies indicate that when dopamine is administered before urine flow has decreased to approximately 0.3 mL/minute prognosis is more favorable. However, it has been observed that in some oliguric or anuric patients, administration of the drug has produced an increase in urine flow which may reach normal levels. The drug also may increase urine flow in patients whose output is within normal limits and thus may help in reducing the degree of pre-existing fluid accumulation.

Conversely, at higher than optimal doses for a given patient, urinary flow may decrease, requiring a reduction of dosage. Concomitant administration of dopamine and diuretic agents may produce an additive or potentiating effect. Low Cardiac Output: Dopamine's direct inotropic effect on the myocardium which increases cardiac output at low or moderate doses is related to a favorable prognosis.

Increased output has been associated with unchanged or decreased systemic vascular resistance (SVR). The association of static or decreased SVR with low or moderate increases in cardiac output is regarded as a reflection of differential effects on specific vascular beds, with increased resistance in peripheral beds (e.g., femoral), and concurrent decreases in mesenteric and renal vascular beds. Redistribution of blood flow parallels these changes so that an increase in cardiac output is accompanied by an increase in mesenteric and renal blood flow.

In many instances the renal fraction of the total cardiac output has been found to increase. Increase in cardiac output produced by dopamine is not associated with substantial decreases in systemic vascular resistance as may occur with isoproterenol. Hypotension: Low to moderate doses of dopamine, which have little effect on SVR, can be used to manage hypotension due to inadequate cardiac output.

At high therapeutic doses, dopamine's α-adrenergic action becomes more prominent and thus may correct hypotension due to diminished SVR. As in other circulatory decompensation states, prognosis is better in patients whose blood pressure and urine flow have not undergone extreme deterioration. Therefore, it is suggested the physician administer dopamine as soon as a definite trend toward decreased systolic and diastolic pressure becomes apparent.

DOSAGE & ADMINISTRATION Do NOT administer if solution is darker than slightly yellow or discolored in any other way. Do NOT administer unless solution is clear and container is undamaged. Discard unused portion.

Dextrose solutions without electrolytes should not be administered simultaneously with blood through the same infusion set because of the possibility that pseudoagglutination of red cells may occur. Do NOT add sodium bicarbonate or other alkalinizing substance, since dopamine is inactivated in alkaline solution. Dopamine Hydrochloride in 5% Dextrose Injection should be infused into a large vein whenever possible to prevent the infiltration of perivascular tissue adjacent to the infusion site.

Extravasation may cause necrosis and sloughing of the surrounding tissue. Large veins of the antecubital fossa are preferred to veins of the dorsum of the hand or ankle. Less suitable infusion sites should be used only when larger veins are unavailable and the patient's condition requires immediate attention.

The physician should switch to a more suitable site as soon as possible and the infusion site in use should be continuously monitored for free flow. The less concentrated 800 mcg/mL solution may be preferred when fluid expansion is not a problem. The more concentrated 1600 mcg/mL or 3200 mcg/mL solutions, may be preferred in patients with fluid retention or when a slower rate of infusion is desired.

Rate of Administration: Administration into an umbilical artery catheter is not recommended. Dopamine in 5% Dextrose Injection should not be infused through ordinary intravenous apparatus, regulated only by gravity and mechanical clamps. Only an infusion pump, preferably a volumetric pump, should be used.

Each patient must be individually titrated to the desired hemodynamic or renal response to dopamine. In titrating to the desired increase in systolic blood pressure, the optimum dosage rate for renal response may be exceeded, thus necessitating a reduction in rate after the hemodynamic condition is stabilized. If a disproportionate rise in diastolic pressure (i.e., a marked decrease in pulse pressure) is observed in patients receiving dopamine, the infusion rate should be decreased and the patient observed carefully for further evidence of predominant vasoconstrictor activity, unless such an effect is desired.

Administration rates greater than 50 mcg/kg/min have safely been used in adults in advanced circulatory decompensation states. If unnecessary fluid expansion is of concern, adjustment of drug concentration may be preferred over increasing the flow rate of a less concentrated dilution. When discontinuing the infusion, it may be necessary to gradually decrease the dose of dopamine HCl while expanding the blood volume with intravenous fluids to prevent the development of marked hypotension.

Suggested Regimen: 1. When appropriate, increase blood volume with whole blood or plasma until central venous pressure is 10 to 15 cm H 2O or pulmonary wedge pressure is 14 to 18 mm Hg. 2.

Begin infusion of dopamine hydrochloride solution at doses of 2 to 5 mcg/kg/min in adult or pediatric patients who are likely to respond to modest increments of heart force and renal perfusion. In more seriously ill patients, begin infusion of dopamine hydrochloride at doses of 5 mcg/kg/min and increase gradually, using 5 to 10 mcg/kg/min increments, up to a rate of 20 to 50 mcg/kg/min as needed. If doses in excess of 50 mcg/kg/min are required, check urine output frequently.

Should urinary flow begin to decrease in the absence of hypotension, reduction of dopamine dosage should be considered. More than 50% of adult patients have been satisfactorily maintained on doses less than 20 mcg/kg/min. In patients who do not respond to these doses with adequate arterial pressures or urine flow, additional increments of dopamine may be given in an effort to produce an appropriate arterial pressure and central perfusion.

3. Treatment of all patients requires constan…