The haemodynamic and myocardial effects of dopexamine: a new beta 2‐ adrenoceptor and dopaminergic agonist.

Abstract

1 Dopexamine increases inotropic state and rate of relaxation independent of changes in heart rate. 2 Dopexamine has a chronotropic effect and results in a decrease in systemic vascular resistance. 3 Dopexamine has a spectrum of action that should be useful in patients with severe heart failure.

Comparison of the effects of dopamine, dobutamine, and dopexamine upon renal blood flow: a study in normal healthy volunteers.

“…For dopamine and dobutamine this appears to be dose related whereas for dopexamine this reaches a plateau at the low dose level. This agrees with previous experimental work which showed that a mild increase in contractility is achieved with dopexamine together with reduction in afterload (Jaski et al, 1986).…”

Inhibition of Uptake1 by dopexamine hydrochloride in vitro)

“…An afterload-reducing agent and renal vasodilator with positive inotropic activity, dopexamine hydrochloride improves cardiac function in patients with heart failure (Dawson et al, 1985;Svensson et al, 1986) and suspected coronary artery disease (Jaski et al, 1986). Plasma levels typically obtained in man (0.02-0.61M; internal reports and Jaski et al, 1986) and in anaesthetized dogs (0.08-0.4tiM; Dr D Hall, personal communication) with therapeutic-dose infusions of dopexamine hydrochloride, would on the basis of these in vitro studies, be within the concentration range able to produce Uptake, block, and it is suggested that the inotropic response is partially mediated by Uptake, blockade and hence potentiation of endogenous noradrenaline.…”

“…Plasma levels typically obtained in man (0.02-0.61M; internal reports and Jaski et al, 1986) and in anaesthetized dogs (0.08-0.4tiM; Dr D Hall, personal communication) with therapeutic-dose infusions of dopexamine hydrochloride, would on the basis of these in vitro studies, be within the concentration range able to produce Uptake, block, and it is suggested that the inotropic response is partially mediated by Uptake, blockade and hence potentiation of endogenous noradrenaline. The ability to block neuronal uptake of noradrenaline is shared by two other clinically used positive inotropic catecholamines, dopamine (Iversen, 1971) and dobutamine, although these are at least ten fold weaker than dopexamine hydrochloride.…”

The effects of dopexamine, a new dopamine analogue, on platelet function in stress.

“…It is a potent 032-adrenoceptor agonist but has no a-adrenoceptor activity. The compound also inhibits neuronal re-uptake of catecholamines (Svenson et al, 1988), so it may affect agonist receptor interactions in this fashion (Jaski et al, 1986). Furthermore it has no appreciable P I-receptor activity (Brown et al, 1985a;Heitz et al, 1983) and evidence suggests it has potent inotropic properties probably via myocardial P2-adrenoceptors (Miller et al, 1981).…”