We studied 12 patients with stable effort angina in a randomized, double-blind, cross-over and placebo-controlled trial to compare the different antianginal efficacy of "acute" and "chronic" (after reaching a steady-state level) gallopamil therapy. Efficacy was assessed using treadmill exercise testing (Bruce protocol) after a 50 mg single-dose and at the end of a nine-dose course of 50 mg of gallopamil (given three times a day). Three daily exercise tests were performed the first, second, fifth and eighth day of the study protocol at 8, 12 and 16 h. Four hours after a single-dose of gallopamil 50 mg both angina-free exercise time and time to 1 mm ST segment depression increased by a mean value of 78 s (p < 0.003) and 53 s (p < 0.03), respectively, with respect to placebo values. Under steady-state conditions exercise time and time to 1 mm ST segment depression increased by a mean value of 59 s (p < 0.009) and 46 s (p < 0.015), respectively, 4 h after the last dose. The duration of the anti-ischemic effects was no longer present after 8 h for both treatment schedules. Furthermore no significant differences were observed on parameters of ischemia after a single dose as compared to "chronic" therapy. The results of this study reveal that, in accordance with the pharmacodynamic properties of the drug, the anti-ischemic efficacy of 50 mg of gallopamil remains for approximately 4 h. Reaching a steady-state condition does not imply a prolongation of the anti-ischemic effect.