Comparison between atenolol and nadolol in essential hypertension at rest and on exercise.

1 The effects of 4 week treatment periods of once-daily atenolol 100 mg, nadolol 80 mg, nadolol 160 mg and placebo on resting and exercise heart rate and blood pressure were compared in a single-blind crossover trial in fifteen patients with essential hypertension. 2 Both atenolol and nadolol, irrespective of dose, reduced resting and exercise blood pressures to the same extent. 3 Nadolol caused a greater bradycardia both at rest and during exercise than did atenolol, thereby effecting a greater reduction in double-product. 4 During progressive treadmill exercise neither atenolol nor nadolol prevented a linear increase in heart rate and blood pressure which were parallel to, but at a lower level than, that produced by placebo. 5 In each individual patient the magnitude of the hypotensive effect produced by one drug was similar to that produced by the other. 6 All the treatment periods resulted in the same linear increase in the patients' perceived exertion scores during exercise despite marked differences in haemodynamic responses evoked by the beta-adrenoceptor blockers compared with placebo. 7 Neither atenolol or nadolol produced any significant change in peak expiratory flow rate compared with placebo.