Sympathicolytic

The sympathicolytic and adrenolytic actions are masked in this case and are overshadowed by the pronounced central action of these alkaloids on the vasomotor center. […] Dihydroergocornine (DHO 180). Crude extracts of ergot are both oxytocic and sympathicolytic.

This, we think, rather confirms Dr. Page’s findings that Apresoline inhibits somewhat specifically the effect of stimulation of the central end of the vagus, although some peripheral sympathicolytic effect is present too. / In contrast to the effect of these three drugs, the Rauwolfia alkaloid, Serpasil, has no sympathicolytic and no ganglionic blocking activity.

Sympathectomy has been shown to alleviate allodynia in animal models, some patients with causalgia respond positively to sympathicolytic procedures, and injection of epinephrine in a stump neuroma may induce intense pain (Chabal et al. 1992; Choi and Rowbotham 1997; Attal and Bouhassira 1999).

Bein: We have compared in the cat the influence of various drugs with a different point of attack (namely a sympathicolytic, “Regitine”; a ganglionic blocking substance, “pendiomide”; a phthalazine derivative, “Apresoline”; and a recently isolated alkaloid from Rauwolfia serpentina, “Reserpine” or “Serpasil”) on the blood pressure rise, produced either by stimulation of the central end of the vagus, or, for comparison, by adrenaline or by noradrenaline.

The rat is pretreated with a sympathicolytic for the following reasons: / In an untreated rat intravenous injection of 0.1–0.5 ml 0.9% NaCl solution (the permitted volume of injection) elicits a pressor reaction. This reaction is completely prevented by means of a sympathicolytic (Dekanski, 1952).

Fig. 7. Action of sympathicolytics on platelet aggregation induced by adrenaline in a concentration of 5.10⁻⁵M

In total, the ECG remained therefore unchanged after treatment with sympathicolytics in 15 men. […] A possibly present depression of the ST-segment and inversion of the T-wave due to myocarditis does not change after application of the sympathicolytics, which is also true for the experimentally provoked ST-depression caused by damage to the myocardium (Furberg, 1967, 1968).

Yocon* is indicated as a sympathicolytic and mydriatric.

Centrally acting sympathicolytics cause a decrease in the sympathetic outflow from the brainstem. This reduction in sympathetic outflow brings about vasodilatation of the peripheral vascular bed with a concomitant drop in the blood pressure