Possible Interaction: Adenosine and Isoproterenol

“ Adenosine had minimal effect on the control HPS cycle length, but in the presence of isoproterenol increased it from 906 +/- 183 to 1,449 +/- 350 ms, P less than 0.001.”

“However, the effectiveness of ISP may be partially due to the complementary effect of adenosine , and, therefore, a combination of the two drugs seems preferable.”

“ Adenosine (100 mumol/l) in the presence of isoprenaline (1 mumol/l) decreased Ica from the level obtained with isoprenaline to 87.5% of basal Ica.”

“ Adenosine significantly lengthened the sinus cycle length in … 909 ± 188 ms, P < 0.05), during isoproterenol infusion (516 ± 67 vs 766 ± 146 ms, P < 0.05), after propranolol (850 ± 153 vs 914 ± 143 … after the combination of propranolol and atropine (662 ± 76 vs 801 ± 121 ms, P < 0.05).”

“The minimal dose of adenosine during isoproterenol infusion with 4 microg/min was higher than that with 2 microg/min in group 2, but not in group 1 patients.”

“The minimal dose of adenosine to terminate tachycardia during isoproterenol infusion of 2 microg/min was greater than that during the baseline state in both groups 1 and 2.”

“ Adenosine as well as carbachol did not affect the positive inotropic response of BDF 9148 or DPI 201-106 but reduced the effectiveness of isoprenaline (P less than 0.05).”

“4 The positive inotropic effect of DPI 201‐106 was not antagonized by adenosine or carbachol, whereas both compounds reduced the positive inotropic effect of isoprenaline.”

“Similarly isoproteranol which induces a sustained elevation in cAMP suppressed the adenosine induced increases in OKT8 and Fc gamma receptor expression.”

“ Adenosine added to isolated electrically driven preparations of human ventricular heart muscle antagonized the positive inotropic effect of isoprenaline (mean EC50 19 mumol 1(-1), n = 9).”

“ Isoproterenol and adenosine , alone or simultaneously, protected hearts but the consecutive treatment gave the highest protection.”