Circulatory effects of the PDE‐inhibitors piroximone and enoximone

Abstract

The isolated circulatory response to intravenous application of the phosphodiesterase (PDE) inhibitors piroximone and enoximone was studied. In a randomized sequence of 30 male patients undergoing elective aortocoronary bypass grafting either piroximone (0.5 mg kg−1; n = 10) or enoximone (0.5 mg kg−1; n = 10) were given during steady state of cardiopulmonary bypass (CPB). A group in which NaCl was given as a placebo served as a control (n = 10). MAP was reduced by piroximone (maximum −23 mm Hg) and enoximone (maximum — 18 mm Hg), whereas it increased in the control (+20 mm Hg). Volume of the extracorporeal circuit indicating venous pooling decreased more pronouncedly in the enoximone patients (–440 ml) than in the piroximone group (–300 ml). Laser Doppler flows (LDFs) increased in both PDE‐III inhibitor groups with the higher and longer increase in the enoximone‐treated patients (LDF‐forehead maximum +44%, LDF‐forearm maximum +33%). Piroximone‐induced increase in both LDFs was less pronounced with respect to both time and degree (LDF‐forehead maximum +30%, LDF‐forearm +12%). Oxygen consumption (VO2) was significantly higher in the PDE‐III inhibitor‐treated than in the control patients. Piroximone and enoximone showed significant vasodilatory properties at the arterial and venous side (= ‘venous pooling’), from which patients with heart failure would profit. Vasodilation could be observed for a longer period and was more pronounced in the enoximone‐treated than in the piroximone patients. Alterations in capillary skin blood flow measured by laser Doppler technique gave evidence for an improvement in nutritive microcirculation, which was slightly more pronounced in the enoximone patients.

Cardiovascular effects of enoximone in isoflurane anaesthetized ponies

“…1986). This phenomenon may also have occurred in the present study, as enoximone was reported to cause both arterial vasodilation (Boldt et al. 1993) and increased myocardial contractility (Installe et al.…”

“…In the present study, a significant decrease in RAP during at least 120 minutes after administration of enoximone to our ponies was also observed, which indicated a reduction in pre‐load of the right heart. This finding might be explained by venous pooling, which has been described in man after enoximone treatment (Boldt et al. 1993; Lehtonen et al.…”

“…Furthermore, in man, enoximone increased organ perfusion and skin capillary blood flow (Boldt et al. 1992), while indications for an improved nutritive microcirculation have been reported (Boldt et al. 1993).…”

Conventional Hemodynamic Resuscitation May Fail to Optimize Tissue Perfusion: An Observational Study on the Effects of Dobutamine, Enoximone, and Norepinephrine in Patients with Acute Myocardial Infarction Complicated by Cardiogenic Shock

“…Enoximone improved capillary skin blood flow, measured by a laser Doppler technique, in a study in patients undergoing cardiopulmonary bypass surgery [29]. In addition, Kern et al demonstrated a beneficial effect of enoximone on hepatosplanchnic oxygen consumption and on liver function in fluid-optimized septic shock patients [30].…”

Cardiorespiratory effects of enoximone in anaesthetised colic horses

“…The cardiovascular effects of enoximone in this study are in agreement with the inotropic, vasodilating and mild chronotropic effects of enoximone described in man (Vernon et al 1991;Lehtonen et al 2004), dogs (Dage et al 1982) and ponies (Schauvliege et al 2007). Due to its vasodilating properties, enoximone can induce a decrease in SVR (arterial vasodilation) (Dage et al 1982;Boldt et al 1993) and a certain degree of venous pooling (i.e. venous vasodilation) (Boldt et al 1993;Lehtonen et al 2004).…”