Reference

Doxofylline differs from methylxanthines in its movement of cytosolic calcium

Doxofylline differs from methylxanthines in its movement of cytosolic calcium. Franzone, Jose Sebastian; Cirillo, R.; Reboani, M. C.In this study， 7440-70-2 and 69975-86-6 are also used. (Ist. Biol. Chemioter., "ABC" S.p.A., Turin, Italy). Int. J. Tissue React., 13(3), 131-8 (English) 1991. CODEN: IJTEDP. ISSN: 0250-0868. DOCUMENT TYPE: Journal CA Section: 1 (Pharmacology) Doxofylline (Ansimar), a new xanthine deriv. with high antibronchospastic activity and no extrapulmonary or cardiac side-effects, clearly demonstrating its inability to mobilize intracellular calcium stores, unlike other xanthins. In vitro, doxofylline does not cause rabbit ear artery contraction under Ca++-free conditions. In vivo, doxofylline does not induce a decrease in the calcium concn. of rabbit washed blood platelets. In the same trials theophylline showed opposite results. Furthermore, doxofylline does not antagonize receptors of Ca-antagonists, and does not interfere with the influx of calcium into the cell. Doxofylline also has a very low affinity for adenosine receptors inhibiting cAMP-phosphodiesterase as does theophylline. The absence of typical methylxanthine side-effects is undoubtedly due to doxofylline's low affinity for adenosine receptors, although this does not explain the absence of cardiovascular effects. The present study presents clear evidence that the inability of doxofylline to cause pos. inotropism can be linked to its inability to induce calcium movement from intracellular stores. .

Chronotropic and arrhythmogenic effects of two methylxanthine bronchodilators, doxofylline and theophylline, evaluated by Holter monitoring: comparison with experimental in vitro and in vivo results

Chronotropic and arrhythmogenic effects of two methylxanthine bronchodilators, doxofylline and theophylline, evaluated by Holter monitoring: comparison with experimental in vitro and in vivo results. Dini, Frank Lloyd (Clin. Pharmacol. Res. Dep., ABC Pharm., Turin, Italy). Curr. Ther. Res., 49(6), 978-85 (English) 1991. CODEN: CTCEA9. ISSN: 0011-393X. DOCUMENT TYPE: Journal CA Section: 1 (Pharmacology) Chronotropic actions of theophylline and doxofylline were examd. in isolated guinea pig atrial prepns., in anesthetized cats, and in patients undergoing bronchodilator treatment. The exptl. results showed a marked cardiac stimulation elicited by theophylline on heart rate, whereas doxofylline provided only a slight increase in the rate of beating. Unlike theophylline, doxofylline did not influence heart chronotropism in humans. The electrocardiog. Holter monitoring showed no detectable effect on cardiac rhythm exerted by doxofylline, while aminophylline caused enhanced heart rate and increased cardiac automaticity. No severe cardiovascular side effects were reported with either drug. Doxofylline appears to possess less cardiac excitatory action than theophylline and therefore should be useful in patients with arrhythmias and chronic airway obstruction.Except for chemicals metioned above, 58-55-9 and 69975-86-6 are also used. .