Effects of a new cardioselective beta-adrenergic blocker (tolamolol) on exercise tolerance in patients with angina pectoris

An Assessment of the Anti-Anginal Effect of Tolamolol, a New Beta-Blocking Agent

The anti-anginal activity of a new beta-blocking agent, tolamolol, was investigated in an open study.

Seventeen patients ( fourteen males, three females) from two centres were given tolamolol in doses varying from 150 mg to 800 mg daily for periods of between one and thirty-four weeks. Records were made of the number of attacks of angina and of the consumption of sublingual glyceryl trinitrate ( GTN). Blood pressure and heart rate were monitored together with possible side-effects and the results of routine laboratory tests. There was an over-all reduction in anginal attack rates and the number of GTN tablets used, although these did not reach statistical significance in the small numbers concerned. Heart rate and blood pressure were similarly reduced. Side-effects were of mild severity and were tolerated or disappeared with continued treatment.

A double-blind trial of penbutolol: a new beta-receptor blocking agent in the treatment of angina pectoris

A double-blind placebo controlled study of angina pectoris with penbutolol was undertaken in parallel groups in fifty-two patients. The duration of the study was six weeks. The dosage range for penbutolol was 8 mg to 50 mg per day. Six patients were dropped from the analysis. Seventeen patients (81%) in the penbutolol series exhibited a 50% reduction in anginal attacks, NTG consumption and subjective improvement. Significant reduction in nitrite intake was observed. Effort tolerance was improved significantly in those receiving penbutolol. Penbutolol was well-tolerated.

Electrophysiologic effects of tolamolol on atrioventricular conduction in man

The electrophysiologic effects of tolamolol (UK-6558-01), a beta-adrenergic blocking agent, were studied in 13 patients by means of intracardiac electrograms and the extrastimulus method. Tolamolol (4 to 30 mg. intravenously) resulted in : (1) prolongation of sinus cycle length (SCL) in all patients (p less than 0.01); (2) prolongation of sinus escape time (SET) in 11 of 13 patients (p less than 0.001); (3) prolongation of A-V nodal conduction time during sinus rhythm in 1i of 13 patients (p less than 0.001); (4) onset of A-V nodal Wenckebach block at longer paced cycle lengths in 10 of 11 patients (p less than 0.001); (5) prolongation of the functional refractory period (FRP) of the A-V node in 11 of 11 patients (p less than 0.001); and (6) prolongation of the effective refractory period (ERP) of the A-V node in 10 of 10 patients (P less than 0.001). Tolamolol had no effect on His-Purkinje system (HPS) conduction time in any patient, including 3 patients with abnormal H-V intervals. Because of the marked increase in A-V nodal conduction time encountered by premature atrial depolarizations, the relative and effective refractory periods of the HPS could not be determined in any patient after tolamolol. Atropine (0.5 or 1.0 mg. intravenously) significantly reversed the effects of tolamolol on: sinus cycle length (4 of 5 patients); sinus escape time (3 of 3 patients); A-V nodal conduction time (4 of 5 patients); and A-V nodal refractioriness (5 of 5 patients).

Double-blind comparison of tolamolol, propranolol, practolol, and placebo in the treatment of angina pectoris

Forty-two patients with angina pectoris have completed a randomized, double-blind trial comparing tolamolol 100 mg and 200 mg with propranolol 80 mg, practolol 100 mg, and placebo, all given three times a day. Tolamolol 200 mg thrice daily was found to be equivalent to propranolol 80 mg thrice daily in anti-anginal efficacy. Anginal attack rates and trinitrin consumption were significantly reduced by all active treatments as compared with the placebo but tolamolol and propranolol were the most effective. Tolamolol 200 mg thrice daily was most effective in reducing blood pressure, while propranolol was most effective in reducing the resting heart rate. All treatments except the placebo significantly increased the amount of exercise which could be performed before angina appeared (exercise work), while tolamolol 200 mg thrice daily significantly reduced Robinson's index when compared with all other active agents. The degree of S-T segment depression induced by exercise was significantly lessened by both tolamolol and propranolol but not by practolol or placebo. There was no difference in patient preference between tolamolol and propranolol but tolamolol at both dose levels was preferred to practolol. Both tolamolol and propranolol are potent adrenergic beta-receptor antagonists and equal in anti-anginal efficacy but tolamolol has the advantage of being cardioselective. It is superior to practolol.