Analgesic effects of adenosine during exercise-provoked myocardial ischaemia

The analgesic potential of adenosine during myocardial ischaemia was studied in patients with coronary artery disease and exercise-limiting angina pectoris. Patients were given a low dose of adenosine or placebo in a double-blind cross-over fashion by continuous i.v. infusion before and during two exercise tests. Adenosine decreased chest pain by 45 +/- 13% (p < 0.02) while heart rate-blood pressure product and electrocardiographic signs of myocardial ischaemia did not change. Ten healthy volunteers received increasing doses of adenosine by continuous i.v. infusion. The heat pain threshold increased in skin covering the chest (p < 0.03) and also tended to increase at the left thenar eminence (p < 0.07). In conclusion, the neuromodulator adenosine can therefore act as an analgesic in myocardial ischaemia.