We evaluated the efficacy of isosorbide dinitrate (ISDN) spray (E-1000) in exercise-induced anginal attacks in 20 patients with stable effort angina pectoris. E-1000 is a newly developed angina-relieving agent which contains 0.125 mg of ISDN in 1 spray and has a quick onset of action when applied to buccal mucosa by spraying. The patients were divided into two groups with different protocols. In protocol 1, the patientsunderwent treadmill exercise tests (Bruce protocol) and 1 or 2 sprays of E-1000 or a placebo were administered at moderate anginal pain, when the exercise was stopped after 1 min of cooling down, and pain-relieving time as well as 50% ST recovery time was measured in a single-blind cross-over manner. In protocol 2, the patients were administered 2 sprays of E-1000 or a placebo at the onset of chest pain and exercise was continued until it reached a moderate degree, and time from the onset of pain to the exercise end-point (onset-end point time), pain-relieving time, and ST recovery time were compared in a single-blind manner.
In protocol 1, no significant differences in pain-relieving time nor in ST recovery time were observed. On the .other hand, in protocol 2, onset-end point time was longer (111.3±41.4 sec vs. 73.1±21.9 sec, P <0.05) and ST recovery time (106±43 sec vs 135±49 sec, P <0.05) was less in the E-1000 run compared to the placebo run. There were no significant differences in the extent of ST depression and heart rate during exercise and the recovery period, while systolic blood pressure at 5th min of the recovery period was significantly lower in the E-1000 run.
It is concluded that the angina-relieving effects of ISDN spray are significant when it is administered at the onset of anginal pain, by suppressing the increase of chest pain as well making ST recovery quicker. ISDN spray is a useful angina-relieving agent due to its quick onset of action and ease of use.