Randomized, placebo-controlled evaluation of lidoflazine in patients receiving beta-blocker therapy with propranolol: improvement in anginal symptoms and exercise tolerance with combined drug therapy.

Twenty-nine patients symptomatic despite beta-blocker therapy were entered into a randomized, double-blind, placebo-controlled, crossover trial of lidoflazine added to propranolol. After clinically documented beta blockade was achieved, patients were randomized to either propranolol plus placebo (P) or propranolol plus lidoflazine (L). Patients initially receiving lidoflazine (group with treatment sequence LP) showed improvement in exercise tolerance from propranolol alone (7.2 to 9.3 minutes, p less than 0.05). Those randomized initially to propranolol plus placebo (group with treatment sequence PL) had unchanged exercise tolerance (7.3 minutes). After 4 months, patients were crossed over to the alternative form of therapy. Patients (group PL) now receiving lidoflazine in addition to propranolol increased their exercise duration (7.8 minutes), but not, significantly. However, patients switched to propranolol plus placebo (group LP) continued to sustain their improved exercise capacity, showing a "carryover" effect. Symptomatic improvement was manifested by a statistically significant reduction in both anginal attack rate and nitroglycerin consumption. The therapeutic efficacy of combined therapy was associated with further blunting of the heart rate response to exercise achieved by beta blockade alone. The combination of agents was well tolerated.