Effects of Dopamine in Man

Abstract

Dopamine, the biochemical precursor of norepinephrine, was infused intravenously into 11 normal subjects and 2 patients. Results of hemodynamic studies in 6 normal subjects indicated that dopamine increased cardiac output and stroke volume in all subjects. Arterial pressure also increased in all subjects with a predominant systolic pressure increment. Calculated vascular resistance decreased in 5 subjects and did not change in the other subject. Changes in heart rate were of small magnitude and were inconstant in direction. Left atrial pressure did not change in 2 patients at a time when substantial increments in cardiac output were produced by dopamine. Comparison of the doses of dopamine and norepinephrine calculated to produce equivalent increments in systolic pressure indicated that dopamine was 1/25 to 1/56 as potent as norepinephrine in this respect. Infusions of dopamine produced relatively small but consistent increments in blood glucose levels. It is concluded that the pharmacological actions of dopamine in man are different from those of epinephrine and norepinephrine. Because of its distinctive properties, dopamine may be useful in the treatment of patients with inadequate cardiac output.

Depression of Ventilation by Dopamine in Man

“…However, high doses of alpha blockers may le re(Iuired to block alpha adreniergic receptors in chemoreceptors (10), so that our studies do niot exclude the possibility that the effect of dopaminie is mediated throuigh alpha receptors. W\e did niot give agents Dopamine has been observed to stimulate ventilationi in manl (24). Infusioni of dopamiine in two stubjects at doses of' 10 and 12 ug/kg per min produced an increase in ventilationi whereas four subjects who receive(ldoses ranging f'romll 5 to 8 ug/kg per min had nio change in ventilation (24).…”

Survival After Shock Requiring High-Dose Vasopressor Therapy

“…We estimated norepinephrine dose equivalences (e-Table 1) based on prior studies, emphasizing studies in septic adults [8][9][10][11][12] rather than children, 13,14 animal models, 15 or healthy adults. 16 Briefl y, we considered 100 m g dopamine equivalent to 1 m g norepinephrine; 1 m g epinephrine equivalent to 1 m g norepinephrine; and 2.2 m g phenylephrine equivalent to 1 m g norepinephrine.…”

Effect of dopamine on regional pulmonary perfusion.

“…Regarding the action on the heart, dopamine had an inotropic action at the dose with which no chronotropic action is elicited (Mc Donald and Goldberg 1963). In 50% of normal men heart rates increase in the dose range of 10-15 µg/kg/min and frequent ventricular extrasystoles are seen above this dose (Horwitz et al 1962). The consensus seems that it is often dangerous and even useless to administer more than 25µg/kg/min (Goldberg 1972;Ramdohr et al 1973).…”

“…It is particularly unique in that the renal blood flow, diuresis and sodium excretion increase while renal vascular resistance decreases following dopamine administration McNay et al 1965;Goldberg 1972). Its dose administered, however, is often critical, because dopamine can either induce vasodilation or vasoconstriction according to the dose administered (Horwitz et al 1962;Black and Rolett 1968;Harrison et al 1969). Vasodilation is not only limited to the renal vessels but also seen in the celiac or the mesenteric arteries (Eble 1964), the coronary (Schuelke et al 1971;Higgins et al 1972) and the cerebral circulation (Essen 1972).…”